# Solar power ~ no more running the engine



## DavidB.UK (Sep 11, 2011)

I know there are lots of threads on solar power but some are quite old and of all of the threads I have read I am still yet to find an answer to the following question...

Has anybody (full-time) liveaboard managed to use solar power for *ALL* of their live-aboard power needs.

Computer+lighting+ refrigeration+Nav lights+water pumps+radio+etc

Basically, can it be done?
Has it been done?
How was it achieved?


----------



## AncientTech (Jun 16, 2012)

DavidB.UK said:


> I know there are lots of threads on solar power but some are quite old and of all of the threads I have read I am still yet to find an answer to the following question...
> 
> Has anybody (full-time) liveaboard managed to use solar power for *ALL* of their live-aboard power needs.
> 
> ...


I am yet to be a live aboard with solar but I do know about amps and that is basically what your going to be breaking everything down to. Also it will depend on specific equipment as well, an old fridge box will run 80-120ah a day. A newer fridge box will run 30-60ah a day and that is if you actually run it all day. most people I know run them only part of the day to maintain the temp. Same thing for the computer. does it require a 1-4amp charger or a 8 amp. with careful planning and a good controller and battery bank there should be no reason you couldn't run it all on solar except for the lack of good sun.
But with that said there is some very awesome progress being made with hydro or tow alternators using some of the same advancements from wind alternators. So even without good sun you could have a way to charge a battery bank. In the event you have no sun or wind you can always follow the old latin rule "Destitutus ventis, remos adhibere"


----------



## WDS123 (Apr 2, 2011)

Theory says it is possible.

reality says not.


----------



## dbrimm (Oct 10, 2007)

The wife and I did for a couple years living on the hook in the caribbean (the Virgins / Puerto Rico area). 

We had IIRC 320 watts in two panels with the appropriate smart charger/controller feeding a bank of 8 T105 batteries. I did have to use the engine to bring the batteries back up once during hurricane season but it was after 5-6 continuous days of heavy rain and no sun. Other than that one time we were fully solar powered. 

The saving grace with us was our lack of refrigeration so didn't have to budget that into our needs power wise. We powered a laptop or two, halogen cabin lights 2-3 at a time (at night), deck lights, stereo, GPS/Radio/Chartplotter, water pump, bilge pump(s), occasional windless use, occasional SSB use, about 1 hour a day watermaker use. This was on a Ohlson 38 FWIW.


----------



## DavidB.UK (Sep 11, 2011)

I suppose the other addition would be a pedal powered generator rigged up to 1/2 an exercise bike would be another solution for top up.

I am a regular runner so if on the hook, 30-40 minutes on a bike would be a better (more useful) workout! especially on the grey days!


----------



## Stumble (Feb 2, 2012)

David,

I know a lot of people who have tried, but none that have done it successfully. The problem is the number of batteries you need plus the sq footage of solar panels you need to be truly independent is costly, and weighs a lot. 

If you can get your requirements down as low as possible, have oversized panels, and a huge battery bank then you can get close. The problem isn't the day after day of sunny skies, but 3-4 days in a row of clouds.

Alternative energy options like wind power, towed power, and bikes can help. But they come with their own set of problems. Typically is is just cheaper and easier to accept a small amount of engine operation to recharge low batteries than it is to deal with the alternatives.


----------



## DavidB.UK (Sep 11, 2011)

Some good points indeed.

I suppose of you approach it from the other direction (looking for where power can be saved) as well as how to create it then a compromise could be found.

If for example I were to:

have a couple of extra batteries

Daily exercise on a pedal powered generator instead of my daily run

a couple of good solar panels

use iPad instead of 27inch iMac

led lighting

low power fridge

...and finally accept the fact that I might occasionally need to use the engine!

Then that could be a happy compromise


----------



## paintpollz (Nov 16, 2011)

yikes, generator bikes and solar panels?

For a newbies prospective, I'm not sure I see return on purchasing things like that. If you had 3-4 marine batterys, and say a 20 hp yamar diesel, how long would it really take at idle to charge the batteries? And how much fuel would you really burn doing it?


----------



## DavidB.UK (Sep 11, 2011)

Not sure?

Please chime in? How much diesel are we talking about using Paintpollz's example?

to qualify my own example a little further, I don't own a laptop I have an iMac which I love but it is quite thirst for power and is the only thing I own which would require an inverter (I have already starting preparing to liveaboard and sold virtually all my material possessions to go towards the boat kitty).

because my computer is not portable an iPad would be useful anyway, as the only alternative (for internet) is a USB dongle or connection through mobile (cell) phone.

I just did a quick search and found this too ($198):









*Product Description*
Pedal power generator ZSFD-1088 is a Brushless Alternator with Gearbox Which can give 50W output with 15-18rpm rotating speed. Because it can give powerful output with low speed, low torque and small size, it is widely used for Exercise Bike, Household Electric Appliance and other Portable charger etc.

The Specification of it is Below:

1. Electric Performance
(1)Rated Rotating Speed: 2000r/min (16RPM with Gearbox)
(2)Rated Current: ≥2500mA
(3)DC Voltage Output: 36-55V DC
(4)AC Voltage Output: 30-50V AC
(6)Line to Line Resistance: 5.8Ω±0.5Ω

2. Mechanical Behavior and Operating Characteristics

(1)Mechanical Noise: <60dB
(2)Output Characteristics: No-load output Voltage varies directly with the rotating speed
(3)Ratio of Speed: 1:125
(4)Weight (Approximate): 3.2kg

3. Dimension: 255mm(L)X120mm(W)X40mm(H)

4. Configuration is below:









Also this...








The multifunctional powerbank includes a 12V internal battery and through the integrated inverter you can also select an ouput of 3V, 4.5V, 6V, 9V and 12V so it can almost always match your mobile devices for charging them.

Even an AC inverter is integrated in the powerbank so you can enjoy 220V power at max.100W. To complete the powerbank is equiped with an integrated flashlight, storage space or adapters etc and an integrated handle for easy carrying and transportation.

The Powerplus Gazelle is a heavyweight addition to the PowerPlus range, offering a truly versatile portable Eco Power solution. The Gazelle is pedal powered, or can be charged by optional car adapter or the included mains adapter. It offers a range of DC outputs along with a USB output and an amazing 230 Volt AC output for running mains applications such as TV's, Laptop computers, mains lighting, refrigerators etc. The main power bank when charged can be slid off it's stand and used anywhere any time to power any appliance up to 100 Watts. The Gazelle also has an integrated bright LED search light with 2 light settings.

Fully charged the Gazelle will shine its integrated 9 LED light for up to 85 hours, a 7 Watt Energy saving light bulb for 10 hours, a 14 inch TV for 1.5 hours, or a Laptop computer for an hour.

Size: 337 x 355 x 267mm


----------



## bljones (Oct 13, 2008)

We do it throughout the summer, living without shorepower. I suppose it boils down to your definition of "liveaboard".
We do not have refrigeration, air conditioning, hot water, television 20" monitors, etc, so we have no big constant loads. Our lighting is all LED, and largely AA battery powered. The only significant electrical loads are the stereo, autopilot and 1000 watt inverter, all of which are used sparingly. We have a single battery starter bank and a single battery house bank. We sail every day, so the incidental generation from the engine running an hour or so a day as we tool out and about and cruise around in addition to the passive generation from our solar panel keeps us topped up. Some may find our lifestyle too primitive, too damn close to camping. 
We manage our electrical loads- for example, charge the netbook and the phone and the handheld vhf while motoring out, always make sure the panel follows the sun as much as possible, and if you don't need it turn it off. We have had a very sunny season so far, which is a BIG variable in the "how big a solar panel do I need" equation. In the UK you are going to get less generation from the same size panel than someone crusing in the caribbean for example. 
The more luxury you have, the more energy you waste, the more wattage you need to generate, until, as someone pointed out, it becomes unsustainable.


----------



## DavidB.UK (Sep 11, 2011)

bljones said:


> We do it throughout the summer, living without shorepower. I suppose it boils down to your definition of "liveaboard".
> We do not have refrigeration, air conditioning, hot water, television 20" monitors, etc, so we have no big constant loads. Our lighting is all LED, and largely AA battery powered. The only significant electrical loads are the stereo, autopilot and 1000 watt inverter, all of which are used sparingly. We have a single battery starter bank and a single battery house bank. We sail every day, so the incidental generation from the engine running an hour or so a day as we tool out and about and cruise around in addition to the passive generation from our solar panel keeps us topped up. Some may find our lifestyle too primitive, too damn close to camping.
> We manage our electrical loads- for example, charge the netbook and the phone and the handheld vhf while motoring out, always make sure the panel follows the sun as much as possible, and if you don't need it turn it off. We have had a very sunny season so far, which is a BIG variable in the "how big a solar panel do I need" equation. In the UK you are going to get less generation from the same size panel than someone crusing in the caribbean for example.
> The more luxury you have, the more energy you waste, the more wattage you need to generate, until, as someone pointed out, it becomes unsustainable.


Good advice, nice to hear from you BL, I have been reading some of your older threads with great interest just a few days ago.


----------



## AncientTech (Jun 16, 2012)

DavidB.UK said:


> I just did a quick search and found this too ($198):


Nice find, I will put that on my research list for sure.


----------



## Capt.aaron (Dec 14, 2011)

You need a sh%t load of pannels, and a lot of sun every day ( which is impossible) And you can almost do it. I've done it for years but have no fridge, manual pumps, and I use a kerosene lamp to read at night.


----------



## paintpollz (Nov 16, 2011)

Thanks for the response BLjones. 

When I get my first boat, hopefully within 5 years, I'll be a weekender and daysailor. I'm curious as to when I have kids, and all the gadgets they will be using. I know when the time comes, I will be using a good deal of power. But if I only need to run the diesel an hour a day on the weekends (not including motoring in/out of the harbor) to support that, I don't see any need to worry about other power generating devices. 4 gallons of diesel (say $20) a weekend to keep the batteries charged is fine with me. But like I said in my previous post, I'm really not sure if that's all it would take, maybe its a lot more than that. 

That footpedal thing is really cool though!


----------



## bljones (Oct 13, 2008)

our yanmar 1GM10 burns about a quart an hour of fuel. 20 gallons will last a while.

As far as electronic device charging, you learn the art of sneak-charging. when you go to the laundromat, bring all of your devices and charge them up while you do your laundry, for example.


----------



## DavidB.UK (Sep 11, 2011)

bljones said:


> our yanmar 1GM10 burns about a quart an hour of fuel. 20 gallons will last a while.
> 
> As far as electronic device charging, you learn the art of sneak-charging. when you go to the laundromat, bring all of your devices and charge them up while you do your laundry, for example.


ha ha ha ha!

I have done that when I forgot my phone's car charger on a long road trip, stopped for a coffee so that I could plug my phone in to charge it


----------



## FarCry (Apr 21, 2007)

I have a 135 watt Kyocera panel, a well insulated fridge that makes ice cubes and keeps them frozen and beer at 34 degrees, 2 T105 batteries and a Victron BMV 601 to monitor things. My boat sits in a slip (not a liveaboard) and is only plugged into shore power after 4 days of straight rain or very heavy clouds (about 6x/year). When out for a week or two, we run the LED interior lights, fans, GPS/chartplotter, stereo, Bebi anchor light, a 20" (roughly) LED TV for movies, water pump etc and don't need to run the engine to charge the batteries. Typically in the morning the batteries are down about 30 amps which is normally made up by the solar panel by early afternoon. When I see that the batteries are topped off I will run a small inverter if anything needs to be charged. Far Cry is only 31' long and doesn't have autopilot or a separate large freezer. We don't really try to conserve energy and it seems to have been working very well for at least a couple of years.

According to the battery monitor the lowest the batteries have ever been was down 80 amps. 

The only time I was having trouble keeping the batteries charged up I discovered that some seagulls had decided to leave some "shade" on the solar panel...


----------



## DavidB.UK (Sep 11, 2011)

FarCry said:


> The only time I was having trouble keeping the batteries charged up I discovered that some seagulls had decided to leave some "shade" on the solar panel...


I wonder... can you eat roasted seagull?


----------



## bljones (Oct 13, 2008)

tastes like chicken.
really lousy chicken.


----------



## DavidB.UK (Sep 11, 2011)

bljones said:


> tastes like chicken.
> really lousy chicken.


ha ha ha! ...Duly noted


----------



## paintpollz (Nov 16, 2011)

FarCry said:


> I have a 135 watt Kyocera panel, a well insulated fridge that makes ice cubes and keeps them frozen and beer at 34 degrees, 2 T105 batteries and a Victron BMV 601 to monitor things.


You my friend, have it figured out.

Thanks for the input.


----------



## copacabana (Oct 1, 2007)

I have two 65w panels and a 210amp battery bank and never have to run my engine to charge unless it has been a week of rain. Rather than look for more amps of power I just reduced my consumption. My boat is 100% LED (the warm yellow kind) and I leave tons of lights on in the evening. My fridge runs on propane and I have modern low-power consumption electronics aboard. We use the laptop for movies and listen to music on the stereo quite a bit. My panels keep my batteries fully charged and I never see the voltage drop below 12.6v. I think that if I add a 12v fridge in a small, well-insulated box (drawing 30 to 40 amps a day) I could still get by using just solar, providing I upped my panels to 2 x 135w and added another 200amps to the battery bank.


----------



## wingNwing (Apr 28, 2008)

We go solar-only for days at a time. Fulltime liveaboards with lots of creature comforts. latitude 27-37 north. So I'm baffled by the replies on this thread that say you can't possibly. How do we make it work?

Efficient refrigeration: Frigoboat keel-cooler. Insulate the boxes, then insulate some more. We draw 25-30 amp-hour/day in 70 degree water, and that includes a shoebox-sized icebox.

All LED lighting.

Solid-state notebook instead of large laptop.

Small handheld GPS chartplotter instead of big screen.

No radar.

2 65-watt solar panels.

When it doesn't work: Autumn to winter, when there just aren't enough hours of daylight, especially when the water is still warm so the fridge has to work hard.

When we're running the autopilot (big power pig)

When I want to spend hours and hours and hours on the computer.

We still need to run the engine for hot water, or use a sunshower.


----------



## TQA (Apr 4, 2009)

DavidB.UK said:


> I know there are lots of threads on solar power but some are quite old and of all of the threads I have read I am still yet to find an answer to the following question...
> 
> Has anybody (full-time) liveaboard managed to use solar power for *ALL* of their live-aboard power needs.
> 
> ...


Sure it can be done. Lots of cruisers are energy self sufficient, it is no big secret.

I have 400 watts of tiltable solar and 675 amp/hrs bat cap. [ 6 x 6v Golf carts. The Adler Barbour Super cold machine makes ice every day. The anchor light is on at night. I am a nethead so somedays the lappie runs for hours. If the sunshines I am fully charged by early afternoon and could easily run the Spectra watermaker which I rarely do as it costs more in Filters than to buy water.

I am on the hook about 355 days a year and run the engine JUST for battery charging about twice a year usually after 3+ cloudy days.

The guys who rely on wind generators usually have two and need to run their engines more often.

As for the guys who have a weedy wind generator that cast shadows on their flexible solar panels welllllll they burn lots of diesel.


----------



## hellosailor (Apr 11, 2006)

Refrigeration is not a NEED. Computers vary widely in the power they NEED. And computers themselves are often not a NEED.

Bottom line is not whether you can survive on solar, but whether you can afford to buy enough panels to feed the lifestyle you WANT. Odds are that you can't, or that if you can, you'll find a genset and fuel to be much less expensive.


----------



## TQA (Apr 4, 2009)

hellosailor said:


> you'll find a genset and fuel to be much less expensive.


Hmmm not sure about that. My 400 watts of solar would cost under a thousand dollars US. Running costs are zero.

A Yanmar generator costs $8000 and diesel is $5 a gallon out here.

Also you have to factor in the noise and pollution plus you will become a social outcast exiled to the far cliffs.


----------



## wingNwing (Apr 28, 2008)

TQA said:


> Hmmm not sure about that. My 400 watts of solar would cost under a thousand dollars US. Running costs are zero.
> 
> A Yanmar generator costs $8000 and diesel is $5 a gallon out here.
> 
> Also you have to factor in the noise and pollution plus you will become a social outcast exiled to the far cliffs.


The bigger issue for me, is that you have to be there to turn the generator on and off every day. I like being able to get away from the boat for a day or two in order to go exploring.


----------



## hellosailor (Apr 11, 2006)

ROFL. Comapring a 400 watt solar panel, which might put out 20-30,000 wat-hours per day, to a 5? 10? kw diesel genset that can put out the same power in just two hours instead of 24?

Yes, the fuel costs money. But you're cleverly ignoring the question of how much power is needed in one day, and whether your 400W solar panel could even make a DENT in that "requirement" including a fridge, computer, and other devices. And of course, since you can't have sun all the time, you'll also have to upsize your battery banks to make sure you can carry through 2-3 sunless days, when the genset wouldn't need that.

Not that solar can't be the answer--if you properly phrase the question. In the past 3 years the prices for solar panels have plummeted but again, depending on what someone's energy budget is, sometimes you simply can't fit enough of them onto a boat. In secure locations, unshaded.


----------



## paintpollz (Nov 16, 2011)

hellosailor said:


> ROFL. Comapring a 400 watt solar panel, which might put out 20-30,000 wat-hours per day, to a 5? 10? kw diesel genset that can put out the same power in just two hours instead of 24?
> 
> Yes, the fuel costs money. But you're cleverly ignoring the question of how much power is needed in one day, and whether your 400W solar panel could even make a DENT in that "requirement" including a fridge, computer, and other devices. And of course, since you can't have sun all the time, you'll also have to upsize your battery banks to make sure you can carry through 2-3 sunless days, when the genset wouldn't need that.
> 
> Not that solar can't be the answer--if you properly phrase the question. In the past 3 years the prices for solar panels have plummeted but again, depending on what someone's energy budget is, sometimes you simply can't fit enough of them onto a boat. In secure locations, unshaded.


This is what I've figured thru previous posts, from a weekender's standpoint, that doesn't even have a boat yet :laugher.

The price of fuel compared to the the energy created to provide luxuries on the water is minimal.

The initial cost for solar, while not incredibly expensive, coupled with the living adjustments to maintain battery power, seems like a greater loss in living comfort, when, primarly relying on a solar system for power regeneration.

I think it would be beneficial to combine the two, but then again, is it really necessary to have 2 systems? It seems for a weekender, no. But a cruiser, definitely.


----------



## FarCry (Apr 21, 2007)

hellosailor said:


> ROFL. Comapring a 400 watt solar panel, which might put out 20-30,000 wat-hours per day, to a 5? 10? kw diesel genset that can put out the same power in just two hours instead of 24?
> 
> Yes, the fuel costs money. But you're cleverly ignoring the question of how much power is needed in one day, and whether your 400W solar panel could even make a DENT in that "requirement" including a fridge, computer, and other devices. And of course, since you can't have sun all the time, you'll also have to upsize your battery banks to make sure you can carry through 2-3 sunless days, when the genset wouldn't need that.
> 
> Not that solar can't be the answer--if you properly phrase the question. In the past 3 years the prices for solar panels have plummeted but again, depending on what someone's energy budget is, sometimes you simply can't fit enough of them onto a boat. In secure locations, unshaded.


Can't follow your math in the first sentence. A kilowatt hour (kWh) is equal to 1000 watts per hour. I think you meant 2-3 kWh per day for the solar output, but maybe not. Or we can make it really simple, 400 watts worth of solar is possibly actually getting 400 watts of power into the battery bank every hour for a few hours each day, in a perfect world.

If we can agree on math and terminology then what I think what you are trying to say is that a 5kw generator can put out "roughly" double the power of the 400 watts worth of solar panels in one hour of run time. And then what? Would you suggest having a massive battery bank to store the excess power? Would you suggest running the genset 24/7 with a minimal battery bank? If not, how long are you suggesting it should be run in a 24 hour period? What was the initial purchase price of the genset? What is the expected life of the unit? What does it cost to run per hour when considering all costs over it's expected life span? Do you have some advanced system logic that automatically turns it on and off when the batteries need charging if the boat is not occupied? Are you running it while heeled over during long crossings? How big is the boat you are basing you assertions on and what exactly is it's electrical budget for an average 24hr period? What latitude is this boat?

Until you decide to provide more information to back up your comments, disagreeing with what I have seen on my boat over the past couple of years and TQA has clearly stated has me wondering what you are basing your claims on. Maybe you are running A/C 24/7....


----------



## hellosailor (Apr 11, 2006)

" I think you meant 2-3 kWh per day for the solar output, but maybe not. Or we can make it really simple, 400 watts worth of solar is possibly actually getting 400 watts of power into the battery bank every hour for a few hours each day, in a perfect world."

Yes, sorry, I multiplied that out wrong. 2-3kWH would be 2000-3000 watts hours, not 20-30,000 watt hours. That is why I am not allowed to practice mathematics across state borders. Or in any of several states at all.

"How big is the boat you are basing you assertions on " They aren't my assertions, the OP gives us no information as to the boat size or energy demands except he "needs" lots of stuff. Let's say the diesel genset (also unspecified, also not mine) is a conventional small diesel with a 5-10kw output. It still comes back to running the genset for two hours, will provide the same power that 400W panel provides in a whole day. And the genset obvisouly can be run longer if needed.

Lifetime costs? Overall economics? Not applicable here. The question was, and is, can the OP run all their stuff all day all night with just a 400W solar panel, as opposed to being able to do so from a genset? Comparing costs doesn't matter, if only one of the solutions can provide the needed power.

And with no energy budget "the rest is an exercise left for the reader" as they say.


----------



## DavidB.UK (Sep 11, 2011)

Hi guys, OP...

I am looking to buy my first little boat (26-30ft) as a liveaboard.
The favourite so far is a little westerley 28.

I will not have access to shore power and have been trying to get some idea of what my power needs will be and once I have the boat, how much of my power needs can I get from solar.

OP was posted to find out if it is possible to be self sufficient from sunlight and a little daily pedal power. Without the need for running the engine to make electricity.

I work from home currently and spend a lot of time of the computer.
27inch iMac is quite power hungry I think... 
_ Line voltage: 100-240V AC
Frequency: 50Hz to 60Hz, single phase
Maximum continuous power: 310W (27-inch models)_
(((iPad could be used for a lot of that time spent online and save power that way)))

Apart from that I am thinking I will require minimum lighting and will use LED lights to conserve power

Small fridge
Coffee machine
water pumps

I wont be running nav lights, GPS etc right away as most of the time I will be moored up on a local river bank

Anything else, just ask...


----------



## AdamLein (Nov 6, 2007)

Make a spreadsheet. Columns:

A: Appliances
B: Energy draw in amps or watts-at-12-volts
C: Usage in hours per day
D: Daily energy draw in Ah or Wh = B * C 

Then sum column D to get daily energy usage.

You can go one step further. Subtract from this the number of Wh or Ah you expect to put into the system on an average day. For example I have a 2A panel, and I mostly sail when whether's nice; I assume I can get 10 Ah into my batteries on a given day. So I subtract those 10 Ah from my daily usage to get a net deficit per day. If this number is negative, you're in luck. If not, you can only stay off-grid for a certain number of average days before you need to go for shore power.

Take your house bank capacity (for me, 150 Ah) and decide how much of that you're willing to use (say, 30% or 45 Ah). You can go off grid for safe_capacity/daily_deficit days.


----------



## Paddyd (Jun 14, 2012)

It can be done with a combination of solar panels and wind turbines 
qty 2 400w to 650w wind turbines placed on either aft of your boat 
a couple panels placed aft 
and a couple panels on top of your cabin
seperate in to two battery banks each running different sections or pcs of equipment 
when you do the math it comes something like this 
25w to 30 w panel will run your radio/cd player all day 
65w panel will run you radio , marine radio and computer all day 
the problem is placement of panels and battery storage banks ...
I run everyweekend with the radio going , run my lights for anchoring out on 2 15w panels hook to a controller and two 12 volt batteries
I just got a 400w wind turbine generator to add to the boat this weekend.


----------



## GeorgeB (Dec 30, 2004)

DavidB.uk, electrical systems for boats can get complicated pretty quickly and you need to do a lot more engineering before we can answer specific questions. The info you have given so far in this thread isn’t enough to support a WAG, let alone a cogent analysis. My suggestion to you is get a copy of the “12 Volt Bible” read it thoroughly, and then come back with questions. You will need to construct an energy budget. Remember the formula: watts= volts * amps. Your computer consumes a whopping 310 watts that converts to 26 amps per hour. Multiply that by the intended hours of usage, factor in the conversion loss through your inverter and you could be looking at 360 amps per day just for that one device. 360 amps is the storage capacity of a 4D battery which you should not run down pass half capacity so you need two. Where are you located at? West coast of Mexico? Wattage on solar panels assumes direct overhead sunlight so the further north you go (like England for example) the efficiency of the panel will drop off considerably. Likewise, what are you going to do on cloudy or raining days? Your production then will drop to only a few amps per hour whereas the computer is using 26. Check the engine specs on your Westerly’s engine. Chances are it is using a 40 amp diode controlled alternator which means for most of the time it’s max output is somewhere around 5-10 amps per hour (your small displacement diesel engine is a lousy way to generate electrons). You have a lot of homework to do.


----------



## DavidB.UK (Sep 11, 2011)

GeorgeB said:


> DavidB.uk, electrical systems for boats can get complicated pretty quickly and you need to do a lot more engineering before we can answer specific questions. The info you have given so far in this thread isn't enough to support a WAG, let alone a cogent analysis. My suggestion to you is get a copy of the "12 Volt Bible" read it thoroughly, and then come back with questions. You will need to construct an energy budget. Remember the formula: watts= volts * amps. Your computer consumes a whopping 310 watts that converts to 26 amps per hour. Multiply that by the intended hours of usage, factor in the conversion loss through your inverter and you could be looking at 360 amps per day just for that one device. 360 amps is the storage capacity of a 4D battery which you should not run down pass half capacity so you need two. Where are you located at? West coast of Mexico? Wattage on solar panels assumes direct overhead sunlight so the further north you go (like England for example) the efficiency of the panel will drop off considerably. Likewise, what are you going to do on cloudy or raining days? Your production then will drop to only a few amps per hour whereas the computer is using 26. Check the engine specs on your Westerly's engine. Chances are it is using a 40 amp diode controlled alternator which means for most of the time it's max output is somewhere around 5-10 amps per hour (your small displacement diesel engine is a lousy way to generate electrons). You have a lot of homework to do.


Thanks George,
I realise that I have lots of homework to do.

I guess the answers I wanted from this thread were to find out if it's possible or not.


----------



## bvander66 (Sep 30, 2007)

We are close but not yet. Probably never will because we use SSB and computer which draws a fair bit. If we didnt have refrigeration then probably could. I know if we have a few good sunny days and run only our refrigeration then the panels can keep up. the other help has been converting all lights to LED.


----------



## GeorgeB (Dec 30, 2004)

David, I don’t want to say that it is impossible, but perhaps close to it. My live aboard friends do it dockside where they have access to 30 amp power (at 120 volts). Higher voltage gives you a lower amp draw for a given wattage. We use solar panels to augment power for our summer cruises and they can be a PITA. You need to angle them so they are as perpendicular to the sun as they can be as efficient as possible, and a shadow cast across a panel will generally kill its output. We rarely use the netbook and our main consumption is the refrigerator and even with the panels (three for a total of around 100 watts), we resort to using the engine every fourth day or so. We have an externally regulated 110 watt high output alternator.


----------



## wingNwing (Apr 28, 2008)

Ditch the coffeemaker. Converting electricity to heat to boil water is notoriously inefficient. Many of these little coffeemakers can use 600 watts, granted its only for a short time, but still ... it's a big, unnecessary power drain if you're trying to go all solar.

Boil water on top of your propane stove instead and use a drip-style coffeemaker such as a melitta. Bonus: the coffee tastes better if the water isn't boiled.


----------



## DavidB.UK (Sep 11, 2011)

I do like my coffee maker, mainly for the fact that it keeps the pot hot and I have it set up with a timer plug right now so I put coffee and water in it cold last thing at night then the coffee is ready by the time I walk down to the kitchen

That said perhaps I need to find other ways...
Does anybody use those little 12v coffee makers designed for long distance truckers and campers.








Or are they going to be much the same deal with regard to power consumption?

Either that or go live somewhere in the tropics and one cup in the morning will be enough and I don't need to get the coffee hot and will get better sunshine...
Maybe year 2 on a bigger boat!


----------



## wingNwing (Apr 28, 2008)

Same issue on the 12-volt; you're still using electricity to make heat. If you're serious about going all-solar, you have to eliminate unnecessary electric drains. Make your coffee on the stovetop then put it in a thermos bottle or other insulated carafe. It'll stay warm at least until mid-afternoon ... and then, its time to switch the beverage of the day to beer, wine, or rum anyway. Problem solved!


----------



## DavidB.UK (Sep 11, 2011)

wingNwing said:


> Make your coffee on the stovetop then put it in a thermos bottle or other insulated carafe. It'll stay warm at least until mid-afternoon...


Brilliant idea!



wingNwing said:


> ...and then, its time to switch the beverage of the day to beer, wine, or rum anyway. Problem solved!


Now you talking!
And I prefer red to white too... so do need to keep the wine refrigerated!


----------



## pointyendfirst (Dec 26, 2008)

David, I have a 1967 Westerly 28 which i got without a working diesel so i just use a 5hp outboard. For power I only use solar but i keep my use very low as i only do short cruises e.g. 7-10 days at a time. I use it for depth sounder, vhf radio, very rare bilge pump, occasional running lights, fans, and occasional tillerpilot. It's not a very big panel, so old I don't know the wattage, but here in Tanzania it works out ok. Would love to hear more about your boat! I can't do PMs since my post count is too low but if you could PM me your email i'd love to correspond as I am in the bashing and tearing part of a major refit.


----------



## wingNwing (Apr 28, 2008)

DavidB.UK said:


> And I prefer red to white too... so do need to keep the wine refrigerated!


LOL - our previous boat had no refrigeration. That's where we learned to drink only red wine, and Pusser's rum with a splash of water ... just because those two were the only drinks we could think of that tasted good warm.


----------



## DavidB.UK (Sep 11, 2011)

What do you use for primary food stuffs without refrigeration then?

What do you use for fresh meats/fish/Dairy/cooked meats?

I suppose I could keep the milk bottle/beer/white wine tied up on a string in the water when moored up and retrieve then as required.

And I 'could' use the same principal for the other food stuffs and keep them in airtight plastic tubs all trailing in the cooler waters...

What did you do? What do others do without refrigeration?


----------



## wingNwing (Apr 28, 2008)

Your solution to trail the wine in the water and bring it up when you need it is pretty creative -- but not quite necessary -- a locker below the water level will stay cool, if not cold, and do the job fairly well. To do without refrig, think cans, and single-servings. We used UHT milk in 250-ml boxes; packets of mustard or mayo from a fast-food place. Hard cheese like Parmesan or individual wax-rind cheese like Dutch Gouda doesn't need refrig the way a block of Cheddar might; we used olive oil instead of butter; and kept all in that cool locker. Canned tuna or salmon, or foil pouches. Veggies like tomato, corn, or green beans are okay canned. Many vegetables will keep a couple of days without refrigeration, again, as long as they're cool and dark, think potatoes, onion, cabbage, carrot. More fragile stuff, we just planned to use the day we got it. A block of ice in a well-insulated fridge box in cool water would last 4 days, so that was another option.

After a couple of years though, it really started to feel like camping out, and we decided to add refrigeration. We researched the most power-efficient fridge we could find, and in our installation it only needs 25-30 amp hours/day - easy for our solar to provide. Took us another year to save up for it, but worth it!


----------



## DavidB.UK (Sep 11, 2011)

wingNwing said:


> Your solution to trail the wine in the water and bring it up when you need it is pretty creative -- but not quite necessary -- a locker below the water level will stay cool, if not cold, and do the job fairly well. To do without refrig, think cans, and single-servings. We used UHT milk in 250-ml boxes; packets of mustard or mayo from a fast-food place. Hard cheese like Parmesan or individual wax-rind cheese like Dutch Gouda doesn't need refrig the way a block of Cheddar might; we used olive oil instead of butter; and kept all in that cool locker. Canned tuna or salmon, or foil pouches. Veggies like tomato, corn, or green beans are okay canned. Many vegetables will keep a couple of days without refrigeration, again, as long as they're cool and dark, think potatoes, onion, cabbage, carrot. More fragile stuff, we just planned to use the day we got it. A block of ice in a well-insulated fridge box in cool water would last 4 days, so that was another option.


 Some good advice there.
I do plan on having refrigeration but the boat currently at the top of my shortlist doesn't have any, but the idea of a 12v coolbox as a short term solution is a good idea.



wingNwing said:


> We researched the most power-efficient fridge we could find, and in our installation it only needs 25-30 amp hours/day - easy for our solar to provide. Took us another year to save up for it, but worth it!


 Awww bless, I know that feeling! As much as I sympathise, it's nice to know I am not alone!


----------



## wingNwing (Apr 28, 2008)

Oh, forgot to mention: when we were fridge-less, we were in northern Lake Michigan, I'm guessing the water rarely got above 20 or 25C, and that only in midsummer? As soon as we got to the Chesapeake where teh water was bathtub-warm in summer, we started saving for the 12-V fridge system.


----------



## wingNwing (Apr 28, 2008)

Do you have access to blocks of ice? Another good tide-you-over solution is to just use the box as an old-fashioned ice box.


----------



## wingNwing (Apr 28, 2008)

Have you seen this thread? http://www.sailnet.com/forums/provisioning/88139-longer-than-stuff-lasts-frige.html#post887282


----------



## DavidB.UK (Sep 11, 2011)

wingNwing said:


> Do you have access to blocks of ice? Another good tide-you-over solution is to just use the box as an old-fashioned ice box.


When I used to work as a temp (travelling) chef, I would often use a broccoli box (waterproof polystyrene) and fill it with ice cubes.

That worked a treat for cold beers and milk for a morning cuppa!


----------



## copacabana (Oct 1, 2007)

Wing'n'wing, has the fridge been living up to your expectations in terms of power consumption? In warm weather has the draw been in the 25 to 30 amp range?


----------



## Tim R. (Mar 23, 2003)

We do it in Maine on 260W of solar. I will also be adding a wind gen.


----------



## wingNwing (Apr 28, 2008)

copacabana said:


> Wing'n'wing, has the fridge been living up to your expectations in terms of power consumption? In warm weather has the draw been in the 25 to 30 amp range?


This chart was pretty accurate, or slightly conservative for 70-75 degree water - we measured that 25-30 amp hours via Xantrex Link 20. We've had the fridge for 8 years or so and it's been wonderfully trouble free and quiet.

Consumption Guide


----------



## wingNwing (Apr 28, 2008)

treilley said:


> We do it in Maine on 260W of solar. I will also be adding a wind gen.


Wow. I assume the 260 W is under ideal conditions? Do you have to angle your solar panels, living as far north as Maine? (We just installed our panels flat and accepted the inefficiency, but we're further south than you - < 40 degrees latitude in summer; <30 in winter.


----------



## DavidB.UK (Sep 11, 2011)

wingNwing said:


> Have you seen this thread? http://www.sailnet.com/forums/provisioning/88139-longer-than-stuff-lasts-frige.html#post887282


Just read it, very interesting indeed!


----------



## DavidB.UK (Sep 11, 2011)

Just had a thought...

Would it (in theory) be possible to power a coolbox with a 'power matched' solar panel.

The reason I ask is that it has just occurred to me that the warmer the weather the more more solar power and the greater the need for refrigeration... a perfect match!

Any thoughts peeps?


----------



## Stumble (Feb 2, 2012)

DavidB.UK said:


> Just had a thought...
> 
> Would it (in theory) be possible to power a coolbox with a 'power matched' solar panel.
> 
> ...


Possible, but not really. Solar panels are notoriously fickle in how much power they produce, loosing as much as half their production from a shadow cast across part of the panel. In ideal situations it could work, but boats are rarely ideal situations.

A better option is to use a battery to level the power usage. So that power is stored as its generated, and used as its needed, and you can disconnect the two events from each other. This is really important because a large portion of a fridges usage will be at night just after cooking dinner. A lot has been removed, warm air has entered and there won't be any sun until the next morning, usually around 10am when power production really ramps up.

What I don't understand is the desirability of trying to get completely off grid. A small 3.5kw generator will put out the equivalent of a massive solar array, and will cost about .5gallons/hr to operate. Installation costs are lower, less prone to breakage or theft, and while no one likes the sound of a generator running, the net cost is likely to be lower with diesel than with a large solar array.

If you are ok going without things like refrigeration, and a microwave, then th enumbers get a whole lot better, and easier to work. But the more modern appliances you want, the easier and cheaper it is to just by a small generator.


----------



## erps (Aug 2, 2006)

> We do it in Maine on 260W of solar. I will also be adding a wind gen.


Same here in the Puget Sound (when the sun is shining). Two panels, 130 watts each, keeps the fridge running 24/7 which has a freezer box. We can make ice for our coke and rum, play Bob Marley on the stereo and watch a movie on a small flat panel t.v in the evening. In the winter, ain't gonna happen in the PNW.


----------



## bassviking (May 28, 2008)

I've been living aboard in a marina in San Diego for at least 3 months on solar only. 

Back in March I put a 230 watt panel flat on top of the bimini and ran that to a Morningstar Sunsaver MPPT Charge controller. I have 4 GC2s from Sams Club bought fresh at the same time as the solar setup for the house bank and a group 31 for the starting battery. 

Since I installed this setup I haven't had the battery charger on at all, ever. I have refridgeration as my biggest electrical drain. My interior lights are all LED except for three flourescent lights. I don't have an inverter and do keep the boat plugged in for occaisional AC electrical needs like a vacuum cleaner or tools. 

I get home from work around 2330 most nights and check the voltage levels. Its usually sitting around 12.7-12.8 unless the fridge compressor is running. In the morning I usually see 12.6. 

So far in three months I haven't had any problems and I'm really really happy with this setup. It works and I haven't worried about electricity much at all since I put it together.


----------



## hellosailor (Apr 11, 2006)

Bass, you have a single 230-watt panel and what size/type refrigerator then?


----------



## xymotic (Mar 4, 2005)

If you think you could 'get by' with an ipad, go for it but I would highly recommend a Macbook air instead. It's the most power miserly thing I've ever seen, recharges fast and runs a long time on its internal batt.


----------



## DavidB.UK (Sep 11, 2011)

xymotic said:


> If you think you could 'get by' with an ipad, go for it but I would highly recommend a Macbook air instead. It's the most power miserly thing I've ever seen, recharges fast and runs a long time on its internal batt.


I *LOVE* the MacBook Air!
Wonderful bit of kit for sure!

I would have thought that the iPad would be better on battery power though?


----------



## wingNwing (Apr 28, 2008)

Near as I understand, the iPad is slightly better (only slightly!) but it is like having "computer lite" in terms of capabilities. It makes a great secondary but most people need at least one real computer/laptop in addition.

(That said, Dan LOVES his new iPad)


----------



## DavidB.UK (Sep 11, 2011)

Would be in addition to my iMac, but significantly less power hungry!
That way I would only turn the iMac on when I needed it.

I had an iPad 1 on for a week that was lent to me on trial, and whilst I concluded that they are fantastic! I found that (for my needs) there was not enough functionality for me to have one as a stand alone machine.

As you say wingNwing a great secondary tool.
If I was to get rid of the iMac and have only a portable, them top spec MacBook Air would be the way to go without any doubt in my mind.


----------



## safira (May 10, 2010)

Why make everything hard? I would suggest that some of you subscribe to the K.I.S.S. program .... as to liveing on a boat with just solar for power .. YES, It can be done and has been done ... I am doing it at this time ... Instead of asking, Can it be done? Say I can do that, then figure it out. Do not make it complicated.
With solar it is a give take thing ... to use this you do not use that ... or you can limit useage to different times ... just use the thing on the shoulders ... 
I use a 6 battery bank system and have all the power i requier to watch movies use a computer and that stuff ... refirigeration is nice to have but a ice chest is good to the only drawback is getting the ice ... refirigiration is make big steps as to powerconsumption and such and being more efficient so hang in the a little longer on that one ...
The main thing that you have to understand is that living on a boat is a lot different then living on land ... if you are tied to a dock then I consider you to be land based .... get off the dock and go to anchoror at least a mooring ... have a tiny bit of adventure ...


----------



## windnrock (May 27, 2012)

We have 6 125Ah batteries in our house bank, 3 85watt Siemens panels producing and avg of 50-60Ah, 2 80watt flexible producing avg 20-30Ah. Our biggest users are the watermaker at 28Ah and the refer at 30Ah. With most lighting now converted to LED and windvane steering we just need to be reasonably judicious. With 700+ Ah in the house bank, we can go a few days without charge. We are thinking of getting an Aquair 100 towed generator, but thanks to you folks I may just get my wife an exercise bike for her birthday! We really only need our engine for maneuvering and emergencies, of course the ultimate would be to have 20hp electric for the dingy too! That is coming as may be total electric motor. Has anyone heard of a mast laminated with solar material? Or flex panels in sails?


----------



## DavidB.UK (Sep 11, 2011)

windnrock said:


> ...but thanks to you folks I may just get my wife an exercise bike for her birthday!


ha ha ha ha!

I have been thinking about manual charging options more and more recently, mainly due to the fact that the terms "bright, warm and sunny day" and the word "England" are not used in the same sentence as often as they might me elsewhere...

I think that if you are the type who works out regularly then sure that expended energy could be put to productive use by using it to charge the house batteries right?

So far I have only come up with a few imaginative ways and (have just this moment) decided to start another thread regarding this and see what ideas the community throws up...


----------



## DavidB.UK (Sep 11, 2011)

windnrock said:


> Has anyone heard of a mast laminated with solar material? Or flex panels in sails?


I googles this a while back and according to what I found we may actually be able to buy solar panel cloth very soon! so we may even see sail makers beginning to sail solar panel sails in the not too distant future!

I think using solar panels (the flexible sticky backed ones) up both sides of the mast is a great idea, but I think (belt and braces) additional fixings would be prudent! I plan to do that myself (solar panels up the sides of the mast! pretty much at least one side will get sunshine throughout the day.


----------



## windnrock (May 27, 2012)

I have seen clear panels used for windows/skylights. I have no doubt it is expensive, but the technology is coming. While most of the flexible panels and material is not as efficient as the ridged panels, it does a better job under low light and indirect light conditions. I think with advances in storage, motor design and panel efficiency, we will see boats with all electric motors, aux as well as the dingy. Till then, "Keep peddling honey, I'm almost done with the email!"


----------



## Bene505 (Jul 31, 2008)

Living last week on the hook and doing 2 days of heavy laptop use, I can say that we do ok with solar (135 + 40) and wind (Fourwinds II), when I'm not working. That's because we are usually on shore exploring or at the beach and not using any electricity during the day. Running the inverter to power the laptop put me at a big deficit. (I don't have a 12v adaptor for my company's laptop.)

We have a Victron battery monitor. I HIGHLY recommend getting one.

I converted the 8 halogen lights in the salon to cheap warm-white LEDs. At 1/10th the price of the good ones, they'll do for now. Specifically, for just the salon, 3.6amps dropped down to 1.1 amps. That's a 70% reduction. I'm slowly working on replacing the lights in the 4 staterooms and the 6 reading lights too.

Note that we don't get too much wind generally -- looking back over my "pre-wind-genny-purchase weather research" leads me to think that by "average wind" they mean "the average of the daily highest wind speeds".

We have a separate freezer. The neighboring fridge gets some cooling though the adjoining wall. When I do install the fridge compressor, I'll need another 135w panel. I'm in the market for 2 of them, if I can find a decent price. I really don't like running the engine for charging. Due to the large size of our bimini, mounting another panel is reasonably straightforward.

We also have long range wifi, which burns about 0.5 amps. That includes the Wireless Access Point on the boat.

Regards,
Brad


----------



## DavidB.UK (Sep 11, 2011)

Bene505 said:


> ...I converted the 8 halogen lights in the salon to cheap warm-white LEDs. At 1/10th the price of the good ones, they'll do for now. Specifically, for just the salon, 3.6amps dropped down to 1.1 amps. That's a 70% reduction. I'm slowly working on replacing the lights in the 4 staterooms...


4 state rooms! Wow that must be some size of boat.
What is it?



Bene505 said:


> We also have long range wifi, which burns about 0.5 amps. That includes the Wireless Access Point on the boat.


When you say long range...
What is the actual working range in real life use?


----------



## Bene505 (Jul 31, 2008)

DavidB.UK said:


> 4 state rooms! Wow that must be some size of boat.
> What is it?


Beneteau 505. We have the 5th cabin up front, but use that for storing sails and fishing poles. We even call it the garage.

The onboard webcam is transmitting pictures every 5 minutes, if you want to see what the interior looks like right now.



> When you say long range...
> What is the actual working range in real life use?


I have permission from the marina 3/4 mile away to use their WiFi, but I'm finding that I'm hitting a subscription WiFi just fine. (The subscription is included with my cable subscription.) There's a thread on it hereabouts Google this: "Bene505 long range wifi site:sailnet.com" (leave the quotes out).

Regards,
Brad


----------



## Kuanyiniv (Nov 18, 2007)

paintpollz said:


> yikes, generator bikes and solar panels?
> 
> For a newbies prospective, I'm not sure I see return on purchasing things like that. If you had 3-4 marine batterys, and say a 20 hp yamar diesel, how long would it really take at idle to charge the batteries? And how much fuel would you really burn doing it?


Have you ever seen these generators?
Bike Power Generators -- Windstream Power


----------



## DavidB.UK (Sep 11, 2011)

Kuanyiniv said:


> Have you ever seen these generators?
> Bike Power Generators -- Windstream Power


They look fantastic!
Somebody posted about them in another thread I started to be specifically about human power!

http://www.sailnet.com/forums/cruising-liveaboard-forum/89496-human-powered-electricity-generating.html


----------



## foggysail (Sep 19, 2010)

GeorgeB said:


> DavidB.uk, electrical systems for boats can get complicated pretty quickly and you need to do a lot more engineering before we can answer specific questions. The info you have given so far in this thread isn't enough to support a WAG, let alone a cogent analysis. My suggestion to you is get a copy of the "12 Volt Bible" read it thoroughly, and then come back with questions. You will need to construct an energy budget. Remember the formula: watts= volts * amps. Your computer consumes a whopping 310 watts that converts to 26 amps per hour. Multiply that by the intended hours of usage, factor in the conversion loss through your inverter and you could be looking at 360 amps per day just for that one device. 360 amps is the storage capacity of a 4D battery which you should not run down pass half capacity so you need two. Where are you located at? West coast of Mexico? Wattage on solar panels assumes direct overhead sunlight so the further north you go (like England for example) the efficiency of the panel will drop off considerably. Likewise, what are you going to do on cloudy or raining days? Your production then will drop to only a few amps per hour whereas the computer is using 26. Check the engine specs on your Westerly's engine. Chances are it is using a 40 amp diode controlled alternator which means for most of the time it's max output is somewhere around 5-10 amps per hour (your small displacement diesel engine is a lousy way to generate electrons). You have a lot of homework to do.


There are two things I am hung up with, first is where to begin and second is where these figures come from.

A computer using over 300 watts????? Really???? Is someone using a workstation instead of a laptop on their boat? That figure needs to be reexamined. Another point I a reference to a 40 ampere diode controlled alternator. Semiconductors today are cheap, there is little cost difference between a 50 ampere diode and a 100 ampere diode but the diode rectifiers are not the limitation or problem with alternators. Enough on alternators, the thing that still confuses me is the high power computer.

Foggy


----------



## TQA (Apr 4, 2009)

A lappie with a normal screen draws from 30 watts to 75 approx. Some of the Kindle style touchscreen tablets are down in single digits though.


----------



## foggysail (Sep 19, 2010)

Wifey and I just finished about 10 days on a mix of anchor and mooring. I have a 7.5kw Kohler generator capable of satisfying any reasonable energy demand that arises. There are costss. First is gas at over $4 plus the noise; even quite generators make noise. I lost it when I found my tired batteries near complete sulfation because of depleted charge due mostly to our 8.3cu ft fridge that includes a defrost cycle.

Sure I/we can give up the fridge but I understand life is short and who knows how long we will be dead. The fridge stays! OH the fridge is powered by a 1kw Zantrex inverter energized with the house batteries, 2 hugh group somethings that weigh about 150#+ each.

I took action a couple of days ago and ordered 2 each 145 watt 20-21vdc panels from Amazon for $320 delivered. I also ordered a MPPT controller for $80 on Ebay....time will tell how close it really is to being true MPPT but it is a start. I just do not want to run my generator any longer than necessary including over an hour in the morning for coffee.

Two 145 watt panels with a decent controller....I do not believe mine is decent should produce in Massachusetts about 15 amperes/hour charge for at least 4 hours/DAY...I HOPE! If my assumptions are sound and if actual use verifies my estimate, I probably will add more panels later. Final note, I am changing those oversized batteries to 4 each T105s or T125s next week.

What are others actually measuring with their panels?

Foggy


----------



## wingNwing (Apr 28, 2008)

We have 2 65-watt panels, at our latitude (<40 in summer; <30 in winter) we have seen as much as 8 amp instantaneous coming in. Our fridge/freezer (keel-cooled and heavily insulated) draws about 30 amp-hours/day in 70 degree water. We converted all our lights to LED; the solar panels take care of 100% of our needs on sunny days including 1 hour of computer time per day. Now looking to transition from laptop with spinning hard drive to a solid state/flash memory type to save energy further.


----------



## erps (Aug 2, 2006)

> Two 145 watt panels with a decent controller....I do not believe mine is decent should produce in Massachusetts about 15 amperes/hour charge for at least 4 hours/DAY...I HOPE!


We have two 135 watt panels. Before we got the panels, we consumed on average 50 amp/day. After the panels, we would show that we were down 20 amps when we got up in the morning. During the day, we restored that by noon and the solar panels ran the refrigeration all day as well with no loss, so when the sun went down, we were fully charged. Next morning, down only 20 amps again, instead of 50. Our panels keeps our batteries very happy.


----------



## DavidB.UK (Sep 11, 2011)

foggysail said:


> There are two things I am hung up with, first is where to begin and second is where these figures come from.
> 
> A computer using over 300 watts????? Really????


Hi Foggy,

The figures below are from apple themselves, mine is either late 2009 or early 2010 (i'm not sure but the power consumption differences are minimal).









This is the culprit...









One advantage it does have is the solid aluminium base means that it could be drilled and mounted securely.


----------



## blistovmhz (Jun 29, 2012)

For the sake of putting all options on the table, if you're not bluewater cruising and just weekend bombing, you can always chuck the diesel entirely, install a small electric drive, a larger prop, and it'll charge your batteries while you sail. Combine this with two small wind turbines and a decent solar outfit. I know this would easily satisfy my electrical requirements. Fridge, laptop, router, small SAN, LED lighting, speakers.

That said, as many others have posted, it's all just thermodynamics. E in E out. Ditch the old car stereo (their built in amps are horrendous power pigs) and use the laptop or phone as stereo. Install a small puter amp. Save yourself 30-40 watts right there.


----------



## blistovmhz (Jun 29, 2012)

As for a desktop in the boat. No. Just no.
The PSU alone, at idle, not even connected to a motherboard, uses 3x the power of my core i5 notebook.
My notebook at idle, screen and wifi on, consumes just shy of 13W. I believe 70W is peak, but my average consumption over the course of an average day (I work from my puter all day) is about 14.5W. 261Wh per day assuming 18h/d of use.
Compare this to that iMac at idle


----------



## Noelex (Jan 23, 2008)

blistovmhz said:


> That said, as many others have posted, it's all just thermodynamics. E in E out. Ditch the old car stereo (their built in amps are horrendous power pigs) and use the laptop or phone as stereo. Install a small puter amp. Save yourself 30-40 watts right there.


This is bad advice.
Car stereos vary a bit in their power consumption, but about 1 A playing 2 speakers at reasonable volumes is typical.

Laptops will use much more than this.

Stay with the stereo.


----------



## DavidB.UK (Sep 11, 2011)

blistovmhz said:


> As for a desktop in the boat. No. Just no.
> The PSU alone, at idle, not even connected to a motherboard, uses 3x the power of my core i5 notebook.
> My notebook at idle, screen and wifi on, consumes just shy of 13W. I believe 70W is peak, but my average consumption over the course of an average day (I work from my puter all day) is about 14.5W. 261Wh per day assuming 18h/d of use.
> Compare this to that iMac at idle


I hear what you are saying and if I were to buy a new machine now, then I wouldn't buy and iMac.

Don't get me wrong I absolutely *LOVE LOVE LOVE* my mac, and now I have made the switch I will always buy MAC but this machine was bought when I was working from home office.

As has already been stated earlier, if I can figure out a way to use an iPad or MacBookAir for most things and only use the iMac when I HAVE to, then that will probably work.

Until I started this thread I didn't realise just how much of a difference there is between running a desktop and a laptop.


----------



## DavidB.UK (Sep 11, 2011)

*Just saw this on a Facebook post, interesting...*









Lloyd's Blog: Solar bottles of light


----------



## MattSplatt (Dec 10, 2010)

For music, when using a computer (only if it was on anyway, of course) or iPod as a source and you only need an amp... search for a Sonic Impact T-Amp, or a 'Class T' based amplifier. These are low power digital audio amps with absolutely ridiculously good audio quality for their price, and they run from 12V. I have one of these - an $80 plastic toy, for gawd sake! - in my lounge room driving an iPod into full size speakers and it's absurd how good it sounds. There are lots of drooling gobsmacked reviews on the intarwebs if you have a look.


----------



## DavidB.UK (Sep 11, 2011)

I bought one of these a few years back when I was working away alot and it has been a fantastic piece of kit!

Has a rechargeable battery pack which will power the speakers (and they are perfectly loud enough for 1 room) for 6-7 hours on 1 full charge!








and it even comes with a remote control!


----------



## hellosailor (Apr 11, 2006)

David, everything old is new again. On tall ships they had "deck prisms" to get light down below before recycled pop bottles were invented. You should still be able to buy them and install them.

These days almost everything is "built to a price" so Foggy's point about the price of alternator diodes misses one important point: If a manufacturer can save ten cents by using a smaller diode, they can and will do so. And that way the final vendor can shave a buck or three off their price and maybe five bucks off the price to the end customer, and that's how the vast majority of the world works. Pennywise and poundfoolish often rules the day.

Eryka, there's something you should be aware of with the energy saving fast SSD drives. Yes they are wonderful but like all solid state "flash" memory devices, they have a finite life. It may be something like 50,000-100,000 cycles, but once each bit has been cycled that many times, they start to fail. Flash cards, USB sticks, SSD drives, all of them have the same issue. Of course hard drives take mechanical wear, but vendors don't always mention SSD drives also are consumables, often with a lifetime much shorter than hard drives have. 

It's all about budget and balance, there's a trade-off to almost every decision. Like running a refrigerator off an inverter, instead of getting a DC model and not having an inverter to consume 5-10% of the power beyond what the fridge needs.


----------



## wingNwing (Apr 28, 2008)

hellosailor said:


> Eryka, there's something you should be aware of with the energy saving fast SSD drives. Yes they are wonderful but like all solid state "flash" memory devices, they have a finite life. It may be something like 50,000-100,000 cycles, but once each bit has been cycled that many times, they start to fail. Flash cards, USB sticks, SSD drives, all of them have the same issue. Of course hard drives take mechanical wear, but vendors don't always mention SSD drives also are consumables, often with a lifetime much shorter than hard drives have.
> 
> .


Thanx Hello, I hadn't known that! Guess I'll have to be even more diligent about backups, just in case. (I'm still lusting after hubby's iPad, though...)


----------



## Paddyd (Jun 14, 2012)

basically you are going to need panels that exceed 240w 
that means 2 to 3 panels 
and add a 400w wind generator for marine usage 
and you will be fine 
try 
BOTC Wind & Solar 10 Best Items needed for Cruising | Galveston Island, TX 77551 
the guy is a smart engineer who redesigned his wind generator in order to really make it for marine use ....


----------



## foggysail (Sep 19, 2010)

I want to go back to that prior post on Apple's computer power. WOW! I am typing on an old IBM T40 powered with an AC adapter rated at 16volts with maximum output of 4.5 amperes for a total of 72 maximum output watts. I doubt the load on the supply is anywhere near the adapter power supply's capability. There is an internal fan in the T40, the computer surface is mildly warm. I would guess that the referenced Apple must be hot even with an internal fan. 

I do agree that thermo is the right way to analyze any power usage but folks, I am almost beyond words regarding Apple's whatever. How long does its battery last......never mind, I am still lost for words.

HELLOSAILOR--- Sure, the things you pointed out about product cost are true. I mentioned the cost difference between a 50 to 100 ampere diode only to illustrate that the diode was really not the problem with alternators. Alternators used in boats at least have a puny cooling system with the only fan that which is mounted on the unit's pulley. All alternators that I am familiar with have a copper wound stationary armature and that as I see it is the major limitation. Copper has a positive temperature coefficient which means the hotter it gets, the higher the copper resistance becomes....which generates more heat..raising the resistance...if not properly cooled and if operated continuously at high currents, it can have a thermal runaway. 

I find here in the forum folks with a great deal of practical experience!!!

Replies by WingNwing sharing her experience with solar and others help me a great deal with my introduction to solar. My days with sail ended when I switched to power so I am not as conservative with energy usage as I once was. I will be later this season or early next change my lighting to LEDs. That does make a lot of sense. My panels should arrive this week, my controller...who know? But I will try to keep current here in the forum with progress and of course, lack of it.

Foggy


----------



## hellosailor (Apr 11, 2006)

Mystery eBay controller, what brand is that? The Genasun MPPT controllers are about the least expensive on the market and they are well more than that. 

Most marine alternators, possibly "all" production boats, aren't really installed the way the alternator makers would recommend. In a car, one set of fan blades may be enough, but for marine use or heavy-duty use, many of them recommend dual fans and specific models allow for the use of one set of blades in front of the alternator and the second set behind it. Apparently once the frame heats up, you're toast, so to speak, so ducting in cool air probably would be the most effective way to increase alternator output on a boat. I've wondered if having an alternator body fluted by a machine shop would create more problems than it solved--but fluting any metal surface is also a great way to get better heat transfer.

A lot of laptops run 100/110W power supplies these days. Remember that the power supply needs to provide roughly twice as much power as the laptop consumes. Half of that runs the laptop (including spinning drives and a bright screen) while the other half is only used when the battery needs charging. Run on AC all the time, and you only need half of the power supply's max power. Run while you're recharging the battery, and you need it all.

That the laptop supplies are often rated 16-19vdc baffles me. I've asked around and never gotten an answer, or even a speculation, on why they need that voltage. Laptop batteries seem to top out around 12 volts (nominal) so in theory, all they would ever need is a 14.4 volt charger. 16 might be justified as conservative design, but by the time they get to 19...no one knows why, and the makers don't talk to civilians. The old Toshibas and IBMs that used to get chosen on boats because they ran directly on 12 volts, are long gone AFAIK. And meanwhile, nothing in the laptop should "need" more than five volts really to run these days. Baffling. 

Thank god these same folks haven't had any interest in redesigning pens and pencils. Although, when I see a four-pack of ballpoints with a $6.49 price tag on them, I really have to wonder who drugged my KoolAide.


----------



## foggysail (Sep 19, 2010)

DavidB.UK said:


> Hi Foggy,
> 
> The figures below are from apple themselves, mine is either late 2009 or early 2010 (i'm not sure but the power consumption differences are minimal).
> 
> ...


Dave--

And on cool/cold days it will provide warmth!
I am stunned! 350watts at 12vdc requires 29 AMPERES! Does that seem logical? Are we interpreting Apple's specification correctly? Yes, the specification does say 350 watts but that is peak power which would occur when the CPU was processing data which would last milliseconds maybe. The number just seems too large.

Even the idle wattage will require 12 amperes at 12vdc. That is a lot of current and if true, I wonder how they even sell those things. Maybe they are just not meant for boats

Foggy


----------



## hellosailor (Apr 11, 2006)

"I am stunned! 350watts at 12vdc requires 29 AMPERES! Does that seem logical?"

The Apple specs are for home and business users, 350 watts at "mains" voltage. 110/220 volts AC, not 12VDC.

Remember that iMac is not a laptop, it is a "desk" computer.


----------



## DavidB.UK (Sep 11, 2011)

The post regarding iMac specs were taken from apple's website.

Perhaps thats the peak load when a super nerd is hacking into the pentagon, but for mere mortals it may be only a few seconds here and there when it is drawing that much. My particular machine is also running 16 (yes sixteen) gig of RAM, which means that it is very rare that I find myself 'waiting for the computer'...

The mac itself though is silent running by the way I don't think it has a fan to honest, clever heat dissipation. For those who are not familiar, the picture showing the screen and a keyboard... that's it! an iMac is basically like a deep flat screen, the computer internals are all contained behind the screen. 

Also... my mac has a 240v supply rather than 110v (just to throw another variable in)


----------



## foggysail (Sep 19, 2010)

Dave--- if you're happy with it, I am happy with it


----------



## Cruisingdad (Jul 21, 2006)

As Wing-N-WIng stated, I am surprised at some of these responses.

Our boat has been off the grid for years now. We have refrigeration, radio, some LED lights, use several home-style lamps, electric heads, water pump, etc. We have a 2000 watt Prosine Inverter. THis runs the microwave, cofee pot, lamps, etc.

We live very comfortably. Our boat does have air conditoining, but we cannot run that off of solar. Not a big problem most of the time as we put up sun shades and open all the hatches and get a nice breeze. 

Our setup is the following:

4 - 130W Kyocera SOlar Panels on top of a dedicated solar arch.
4 - 4-D Lifeline AGM batteris for the house bank, totalling 840 ah.
1 - Outback MPPT MX60 SOlar CHarge Controller
1 - Xantrex Prosine 2.0 (2000 watt) Inverter/charger
1 - Mastervolt 3.5 kw Diesel Generator

We use, ballpark, 160-180 ah day on the hook. THis does not include AC, of course. We generate, 200-220 ah in solar/day. We have generated more solar than this and we have used more power than 180 ah/day... but these are good averages and being very reasonable.

You do get the cloudy days which drops the output of solar down considerably. THat is why we also have a very large batery bank to get us through those days. The trick is over sizing your battery bank and oversizing your solar panels so that you can make it through the cloudy days.

The wife and I recently agreed that the solar setup is the best thing we have put on the boat. It is quiet and watches out over itself. THere is no maintenance and it is completely trouble free. However, it is very expensive.

Diesel will have to get really expensive before it becomes economically viable to take solar over running your main. Now, if you throw a diesel generator in there, then all bets are off as you can easily rack up $15000 on a diesel generator installed. But my solar investment is as follows:

$3750 for custom solar arch, installed.
$650ish/panel for a total of $2600
$400ish for the Outback MPPT solar charge controller
$300ish in wire and fittings.

All together, I am ballpark: $7000 dollars into this solar setup. THat is a LOT of diesel in your main engine. THis also does not count the 1600 or so dollars in batteries (which I got at a steal). So a high end solar setup is not cheap and I think anyone would have a tough time making a good economical decision from it. But like I said, it is awesome now and the best thing I have put on my boat. It makes us fairly worry free about our energy budget. And should we ever want, we can crank up the generator and have air conditioning down below and charge the batteries that way. 

As far as saving energy, WIng-N-WIng was right again about the coffee pot. We do use an electric coffee pot, but have a bodum also. If you are going to use an elecric, we found that the carraffe style coffee pots are the best because then you are only paying for the electricity to make it - not keep it hot. At the very least, when you are done making coffee, turn it off and pour it into a carraffe. 

LED lighting helps, but is also expensive. Look into lamps with CFL or LED bulbs that you can buy at Costco inexpensively as another option. What we do is everytime a halogen bulb goes out, we replace with a LED. 

ANother energy saving tip is replacing your anchor light with an LED light. THat is a lot of energy going to waste up there for those that anchor out a lot like us.

THe refrigeration is going to be one of the largest consumers of electricity. I personally would never cruise without a fridge and freezer. It makes life much more enjoyable. A very cheap way to decrease your electrical use on your friedge is to go to Lowes and buy styrofoam sheets. THey are cheap and come in long runs. Cut them to fit into your box. Before taping them into the inside, completely wrap them in Foil Duct tape. THis reduces the mold, makes it easier to clean, and makes them last longer. If you have a top opening fridge, make panels that sit across the top with at least two openings. THat way, when you want to open the fridge to get something out, you open it, then pull out only one panel which reduces the exposure and keeps more cold air in. If you have a front door opening style, do the same - but also add in thin hanging sheets of plastic that you have to reach through to get to your stuff. You can see through it but at least when you open the door, you don't dump all your cold air out. FYI - the front door opening fridges, though convenient, are a terrible waste of electricity and cooling capacity. Lastly, arrange your fridge/freezer so that you have easy access to the most used things and always put it back in the same place. THat minimizes the shuffling around in the fridge (especially with those like me who have kids).

Hope all this helps.

Brian


----------



## Cruisingdad (Jul 21, 2006)

Our Outback MPPT Charge Controller:










Our Solar Panels:


----------



## hellosailor (Apr 11, 2006)

"Also... my mac has a 240v supply rather than 110v (just to throw another variable in) "
Watts is Watts, David. they don't care about Volts.


----------



## DavidB.UK (Sep 11, 2011)

hellosailor said:


> "Also... my mac has a 240v supply rather than 110v (just to throw another variable in) "
> Watts is Watts, David. they don't care about Volts.


ok 
my mistake.

I am struggling to wrap my head around the relationships between *amps* vs *volts* vs. *watts* TBH

Anybody recommend any reading materials to help me to elevate my level of understanding?

Electrics for dummies perhaps???


----------



## blowinstink (Sep 3, 2007)

DavidB.UK said:


> ok
> my mistake.
> 
> I am struggling to wrap my head around the relationships between *amps* vs *volts* vs. *watts* TBH
> ...


Amps measures "current"
Volts measures "electrical force"
Watts measures "power" consumed

If you were drinking an electrical milkshake (alcoholioc of course since this is sailing) the Amps would be how fast you were sucking on the straw, the volts would be how much sugar was in the milkshake and the watts would be the resulting calories (impacted by both the speed at which you sucked it through the straw and the amount of force / sugar - thus AxV=W or in traditional terms I (current) *V (voltage)=P (power)

You'll probably need your own metaphor  but you'll get it.


----------



## DavidB.UK (Sep 11, 2011)

blowinstink said:


> Amps measures "current"
> Volts measures "electrical force"
> Watts measures "power" consumed
> 
> ...


:laugher That's a great mteaphor, made me chuckle. Thank you


----------



## foggysail (Sep 19, 2010)

hellosailor said:


> Mystery eBay controller, what brand is that? The Genasun MPPT controllers are about the least expensive on the market and they are well more than that.
> 
> Most marine alternators, possibly "all" production boats, aren't really installed the way the alternator makers would recommend. In a car, one set of fan blades may be enough, but for marine use or heavy-duty use, many of them recommend dual fans and specific models allow for the use of one set of blades in front of the alternator and the second set behind it. Apparently once the frame heats up, you're toast, so to speak, so ducting in cool air probably would be the most effective way to increase alternator output on a boat. I've wondered if having an alternator body fluted by a machine shop would create more problems than it solved--but fluting any metal surface is also a great way to get better heat transfer.
> 
> ...


OK, first thanks for your reply. The so called MPPT that I purchased is found at:

www .ebay.com/itm/180890446908?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Not sure if posting URLs is permitted so you might need to add the hppt stuff and delete the space after the www.

How it performs remains to be seen. I selected this model for price plus I did not want the electrical noise that a buck converter generates.

Alternators--- cooling is a must! Years ago in another life, I found many high voltage, high power devices were water cooled. I often wonder why alternators at least the high power units for marine use are not water cooled. Some of the methods are simple such as wrapping a copper tube around the outer periphery of the case. Sure, it needs to be secured for heat transfer, soldering or brazing would be almost impossible in the field but not in a manufacturing facility.

Foggy


----------



## wingNwing (Apr 28, 2008)

blowinstink said:


> Amps measures "current"
> Volts measures "electrical force"
> Watts measures "power" consumed
> 
> ...


Okay, try voltage is analogous to the alcohol content (proof) of the drink, amps is speed with which you down shots or glasses, and watts is the resulting hangover.

Nice metaphor dude!


----------



## blistovmhz (Jun 29, 2012)

I think of Amps vs. Volts vs. Watts like water flowing through a pipe.
"D" = Pipe diameter = Volts
"S" = Speed of water flow = Amps
"F" = Overall throughput = Watts.

If we want to attain overall throughput of "F", we can use a big pipe with slow flow or a skinny pipe with a fast flow. A bigger pipe = less pressure to attain "F". If you go with a skinnier pipe, you must increase "S" to attain "F", but this results in higher pressure.


----------



## DavidB.UK (Sep 11, 2011)

foggysail said:


> OK, first thanks for your reply. The so called MPPT that I purchased is found at:
> 
> www .ebay.com/itm/180890446908?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
> 
> Foggy


Your link was not working so I searched for the item number, the link is here MPPT 30A Solar Power Controller Regulator Converter 12V/24V Auto Switch 720W aub | eBay

I am not a mod but links seem to be ok as long as you are not promoting your own products and it is relevant to the thread


----------



## blowinstink (Sep 3, 2007)

blistovmhz said:


> I think of Amps vs. Volts vs. Watts like water flowing through a pipe.
> "D" = Pipe diameter = Volts
> "S" = Speed of water flow = Amps
> "F" = Overall throughput = Watts.
> ...


I don't get it. How many proof is the "water"?


----------



## blowinstink (Sep 3, 2007)

wingNwing said:


> Okay, try voltage is analogous to the alcohol content (proof) of the drink, amps is speed with which you down shots or glasses, and watts is the resulting hangover.
> 
> Nice metaphor dude!


Now, there's a sailor!


----------



## foggysail (Sep 19, 2010)

Cruisingdad said:


> As Wing-N-WIng stated, I am surprised at some of these responses.
> 
> Our boat has been off the grid for years now. We have refrigeration, radio, some LED lights, use several home-style lamps, electric heads, water pump, etc. We have a 2000 watt Prosine Inverter. THis runs the microwave, cofee pot, lamps, etc.
> 
> ...


Brian--

WHAT A GREAT POST, GOOD JOB! Yes solar is expensive although quickly becoming more affordable. It was doing GREAT before the GREAT ONE imposed a tariff on China which I do not agree with when we are in a world economy but what do I know.

Today one can purchase a polycrystalline 140 watt panel for $160 delivered from Amazon where I purchased 2 each. The poly panel had advantages and disadvantages over the monocrystalline which cost more today. If I was purchasing panels for my home roof where surface area was critical, mono would be the way to go.

Even the MPPT controller I purchased for $80 is a great step in the right direction if it achieves anything close to what one expects in a MPPT controller.

You comments on insulation make sense! I will not go to that extreme because we do not live on our boat which spends most of its life tied to a finger pier. How can one not applaud the concept of using a vacuum storage container for coffee. Because I have two battery concepts, one for 12vdc power and another for 24vdc power I will need to run our generator in the mornings for coffee and charging the 24vdc bank. It is used to power my Maxwell HWC2200 windlass along with a Freedom inverter which provides power for a CFL lamp along with our microwave. Our fridge which is indispensable gets powered from a 1kw Xantrex pure sinewave inverter energized from a 12vdc bank.

My newly purchased panels should remove most of the power bite our batteries currently suffer. If I need to increase our capacity, I will at that time purchase another panel.

HEY! I cannot leave this post without commenting on your pictures! Another great job. There will be many who read this thread who will gain insight and knowledge from your post.

Foggy

EDIT: I installed a hard top which is about 10'X9'over my rear deck. I expect to have no problems mounting my collectors.


----------



## Maine Sail (Jan 6, 2003)

foggysail said:


> Brian--
> 
> WHAT A GREAT POST, GOOD JOB! Yes solar is expensive although quickly becoming more affordable. It was doing GREAT before the GREAT ONE imposed a tariff on China which I do not agree with when we are in a world economy but what do I know.
> 
> ...


Foggy,

I wish you luck with your "MPPT" controller. I have removed two controllers that looked identical to that one. They were made in China, sold on Flea Bay, and were NOT MPPT despite being sold as such. One was not even PWM but rather a cheap ON/OFF shunting controller... One was replaced with a Genasun MPPT and the other with a Morninstar. The performance improvement was immediate. One of the controllers literally charged to 13.7V that is it...... It would then shut off until battery voltage fell and it would turn back on and shut off again at 13.7V. MPPT controllers don't behave like that.

I have some more information on installing solar that may not have been brought up in this thread at the link below...

*Installing A Marine Solar Panel*

Generally I think the Morningstar controllers are some of the most reliable in the marine environment but the Outback products are good too but limited in smaller ranges.. For small arrays under 150W the Genasun's are hard to beat for an MPPT... I was just on my boat watching my panel pump 4.8 -4.9A into my battery bank on a panel rated at 4.4A.... That's about a 10% improvement. It is always cheaper to put the money into a panel if starting from scratch but if you're maxed on panel size then an MPPT can help_ some_..


----------



## foggysail (Sep 19, 2010)

Maine Sail said:


> Foggy,
> 
> I wish you luck with your "MPPT" controller. I have removed two controllers that looked identical to that one. They were made in China, sold on Flea Bay, and were NOT MPPT despite being sold as such. One was not even PWM but rather a cheap ON/OFF shunting controller... One was replaced with a Genasun MPPT and the other with a Morninstar. The performance improvement was immediate. One of the controllers literally charged to 13.7V that is it...... It would then shut off until battery voltage fell and it would turn back on and shut off again at 13.7V. MPPT controllers don't behave like that.
> 
> ...


Well, that is nice to know! I hope it is not just a switch inside this surprise box. If you found junk in a similar product, most likely what is being delivered will also be junk. Even if wired directly assuming 50% of the panel ratings or that of one panel at 140 watts under ideal conditions, a 21vdc panel should yield almost 7 amperes. A far cry from say 80% using MPPT wich would then be (.8)*(280)/13vdc = 17 amperes!!!

We are in the middle of our season. If I purchased a pig, I will swallow the pig. My plan for next season was to design my own a MPPT controller over the winter for use next season. That should not be too hard to do using current microcontroller technology such as one of Microchip's PIC18F4550. $80 was worth the risk.

Foggy


----------



## Cruisingdad (Jul 21, 2006)

foggysail said:


> Brian--
> 
> WHAT A GREAT POST, GOOD JOB! Yes solar is expensive although quickly becoming more affordable. It was doing GREAT before the GREAT ONE imposed a tariff on China which I do not agree with when we are in a world economy but what do I know.
> 
> ...


THank you for the kind words.

I do want to make a few clarifications:

1) I helped another sailor install his solar panels and MPPT charge controller on his boat in FOrt Lauderdale. He got his stuf off of Ebay. It did not work and was very poorly consructed. The connections under the panels would not accept anything but vbery small diameter wire, were not water tight, did not have blocking diodes, and were poorly soldered in. THe "mppt" controller was a little box not much bigger than my hand with a few lights on it and I won't even comment on its lack of functionality. I do wonder, in this instance, if you don't get what you pay for. My advice is to independently monitor those panels and output and keep your receipt ready.

2) Why do you have to start your generator to make coffee if you have a inverter? And why isn't your windlass 12v? Why are you inverting for your fridge? Is it not also 12v? What is the make of the fridge? Sems like if you are inverting to make a 12v appliace run, you are losing power in the process. Just me.

3) Not sure where you are located, but be thoughtful about being able to get those panels down in a reasonable amount of time if you are in a hurricane zone like me. I do like the hard dodgers and that should make a good place to mount IF (big if) the boom does not sit over the panels. I will cautioun you that most panels do not work (and can actually suck power backwards) if shaded too much. What too much is depends I guess on the panels (and whether they have Bdiodes), but I would venture anything more than 20%. Maybe not even that much???

Anyways, good discussion.

Brian


----------



## Cruisingdad (Jul 21, 2006)

Maine Sail said:


> Foggy,
> 
> I wish you luck with your "MPPT" controller. I have removed two controllers that looked identical to that one. They were made in China, sold on Flea Bay, and were NOT MPPT despite being sold as such. One was not even PWM but rather a cheap ON/OFF shunting controller... One was replaced with a Genasun MPPT and the other with a Morninstar. The performance improvement was immediate. One of the controllers literally charged to 13.7V that is it...... It would then shut off until battery voltage fell and it would turn back on and shut off again at 13.7V. MPPT controllers don't behave like that.


I see you beat me to it. I had the same issue on a boat install in FLL.

Brian


----------



## foggysail (Sep 19, 2010)

Cruisingdad said:


> THank you for the kind words.
> 
> I do want to make a few clarifications:
> 
> ...


 Brian--- no boom on this 40' Silverton with twin Crusaders!

Yes, from what I now learn the MPPT controller is described elsewhere as a POS. I will monitor the output carefully although as I type, I am expecting the worse. It will not be the end of life if as expected it turns out to be that POS others have described including a video of a Harbor Freight displaying a similar device.

Windlass! I cringed at the wiring losses I expected if I resorted to a 12vdc windlass because I wanted something, no, I wanted the biggest dog in the park! I wanted to be ABSOLUTELY SURE that woof would get my anchor out of whatever the bottom happened to be back onto the bow of my boat. I would have purchased an AC powered windlass that I could run with my genny if I had found one. I also wanted to use the existing wiring already on the boat that previously powered a small, too small Goode windlass.

So I have a Maxwell HWC2200 which is huge! It lowers and retrieves my 5/16" chain rode with an 80# Maxium Supreme anchor attached as if it was a toy.

The 24vdc system does just as expected. If I could have changed everthing in the boat to 24vdc I would have. That task was just too big so I settled with using the 24vdc for the windlass and some lighting along with my microwave.

Back to the panels/controller. If the POS controller does not have a reverse polarity protection diode, I will make sure I install one. Earlier I posted about designing my own next winter. That is something that will happen!!!

Location-- Massachusetts. And yes we do get storms although other areas get pounded far more often than us.

Foggy

EDIT: I junked an old Norcold which was not cold but was very noisy for an apartment 8.3 cubic ft fridge made by Summit. We wanted black, it came only in white. I sprayed it black....looks nice. The inside shelving was made from wire, I replaced that with 1/2" Lexan...that works out well. I power the thing with a 1kw Xantrex true sine wave inverter when dock or generator power is unavailable. I wired in a relay that automatically switches over from dock/genny power to the inverter power. This fridge is very quite, has automatic defrost, an interior light. It is great!


----------



## Cruisingdad (Jul 21, 2006)

foggysail said:


> Brian--- no boom on this 40' Silverton with twin Crusaders!
> 
> Yes, from what I now learn the MPPT controller is described elsewhere as a POS. I will monitor the output carefully although as I type, I am expecting the worse. It will not be the end of life if as expected it turns out to be that POS others have described including a video of a Harbor Freight displaying a similar device.
> 
> ...


Ahhh... that explains a lot. Did not realize it was a motor boat. I salivate everytime we are invited over to someones motorboat and they open up their 25 cf fridge and not so quickly plop cubes of ice into our cups for a drink! I realize they do it for effect. As a good friend of mine once said to his wife anchored off of Columbia, "Here is your one cube of ice. Make it last. Do you realize how much diesel it takes to make that ice!??"

HEHE!

Good luck with it all. If you have any questions about it, let me know. At the least, you might consider keeping your panels and trying a different charge controller??? I am very pleased with the Outback. Hey, it's just money, right??

Brian


----------



## MarioG (Sep 6, 2009)

Yes it can be done,we have been running on solar power for over a year now with great results this includes having a TV , computer,cell phone and a few chargeable power tools , water& bildge pumps aboard. This is all from 1 135w panel. I'm sure when and if we do a frige unit I will need another panel for it. All the lighting has be changed to LED. We have gone 3 days running off the 2 house batteries before figureing out a connection for the solar panel had become undone, so we know one or two days with out good sun doesn't seem to be a problem.


----------



## AdamLein (Nov 6, 2007)

The analogies above are not great. Voltage is nothing like sugar, or alcohol concentration, and certainly nothing like pipe diameter.

Buy this book:

Amazon.com: Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems (9780071432382): Nigel Calder: [email protected]@[email protected]@http://ecx.images-amazon.com/images/I/[email protected]@[email protected]@51COhV9x6TL


----------



## Bene505 (Jul 31, 2008)

AdamLein said:


> The analogies above are not great. Voltage is nothing like sugar, or alcohol concentration, and certainly nothing like pipe diameter...[\QUOTE]
> 
> The pipe analogy works extremely well if you use:
> 
> ...


----------



## foggysail (Sep 19, 2010)

Bene---

My mind wandered for a moment and I started to think of gallons of amperes

Foggy


----------



## tdw (Oct 2, 2006)

Seems to me that one of the mistakes people make with boat power is to try and make the boat fit the equipment rather than t'other way round. 

Other point is that presuming you want hot water for a shower then you'll need to run the engine an hour or so a day anyway which is a big assist for your panels.

Beyond that we have circa 300w of solar panels plus wind gen. Wind gen is currently not working for some reason and we'll typically need to run engine for an extra hour a day if using notebook puter and its a bit overcast. Sunny days the panels will cope with the hot water engine run time. With wind gen fully operational and only running the thing during the day (noise) we cope quite happily. 

We've resisted the temptation to have a decent espresso machine. Even the lowest of the breed sucks up 750w albeit not for long. Nonetheless we'll stick with our venerable old stove topper. Probably increase fridge capacity in due course so will add another panel at same time. 

We use an oil lamp for general lighting , currently halogens for reading but as with BBQ boy we are switching to LED as they blow.


----------



## Cruisingdad (Jul 21, 2006)

tdw said:


> Seems to me that one of the mistakes people make with boat power is to try and make the boat fit the equipment rather than t'other way round.
> 
> Other point is that presuming you want hot water for a shower then you'll need to run the engine an hour or so a day anyway which is a big assist for your panels.
> 
> ...


I wonder if you get more of a winter than we do? We can generally go about three days on the water heater without needing to either turn on the generator or main. Is it well insulated?

Brian

PS I have two more 130 watt kyocera panels in storage still in the box. I am actually thinking about finding a way to hook them into the system as well. What would that be... 780 watts of solar! When cruising, I can make money as a mobile power company for small islands.


----------



## hellosailor (Apr 11, 2006)

Brian, you can put up USB cords and offer "iPad and ihone recharging, $1 each" or better yet, become an EV recharging station.<G>

But seriously, doesn't EVERYONE have colder winters than Florida? I know when it gets down to 68F/20C all the old folks bolt their doors and put on their warm clothes, but...if you don't keep salt and a snow shovel handy, seriously? Winter?


----------



## tdw (Oct 2, 2006)

Cruisingdad said:


> I wonder if you get more of a winter than we do? We can generally go about three days on the water heater without needing to either turn on the generator or main. Is it well insulated?
> 
> Brian
> 
> PS I have two more 130 watt kyocera panels in storage still in the box. I am actually thinking about finding a way to hook them into the system as well. What would that be... 780 watts of solar! When cruising, I can make money as a mobile power company for small islands.


Brian,
Sydney weather is quite seasonal. Unlike e.g. Queensland we have a distinct, albeit by North American standards mild, 40 degrees is bloody cold for us, winter warm autumn and spring and hot sub tropical summer.

How big is your tank ? Our problem is not so much that the water in the tank goes cold but that we use it all up. I do accept btw that with only the two of us on board we are somewhat profligate with out hot water usage for showers. We tend to head to some form of civilisation every couple of weeks at least plus we have the water maker so water usage in itself is not a big issue for us.

Summer of course is very different cos we'll usually shower with a cold rinse after a swim but in summer we generate more than our daily needs from solar. Its only in winter when a hot shower is a nice bit of luxury and with less sunshine for solar that we need the engine. Ironically in winter Sydney has less wind than summer so we don't get much out of the wind genny.


----------



## Cruisingdad (Jul 21, 2006)

I think it is 12 gallons. But it really keeps it hot a long while... suprisingly such.

Brian


----------



## maiden (Mar 9, 2002)

Not living aboard any longer, but I could do all but the refrigerator full time on the solar panels. Every other day I would run the engine. Now I have a question also, I have 2 85W solar panels mounted and I am looking for a solar panel regulator so I don't overcharge my batteries. I have 2 battery banks and was wondering if there is a regulator available that can regulate the two separately?


----------



## mdbee (May 2, 2007)

Like this one?

Morningstar Corporation » SunSaver Duo

I have used this one on several installations.



maiden said:


> Not living aboard any longer, but I could do all but the refrigerator full time on the solar panels. Every other day I would run the engine. Now I have a question also, I have 2 85W solar panels mounted and I am looking for a solar panel regulator so I don't overcharge my batteries. I have 2 battery banks and was wondering if there is a regulator available that can regulate the two separately?


----------



## Cruisingdad (Jul 21, 2006)

mdbee said:


> Like this one?
> 
> Morningstar Corporation » SunSaver Duo
> 
> I have used this one on several installations.


I have not used that unit, but I think Maine Sail reccomended it and I trust his reccomendations. WHy don't you refer back to this thread and ask him about it?

FOr larger installatoins, I think Outback is the way to go.

Brian


----------



## smurphny (Feb 20, 2009)

Would like to see some non-theoretical, longitudinal data on the number of watt/hrs actually captured by solar panels on boats. I've seen numbers all over the place. I wonder how many real-life watts can be counted on per 100 watt panel.


----------



## hellosailor (Apr 11, 2006)

"Would like to see some non-theoretical, longitudinal data on the number of watt/hrs actually captured by solar panels on boats."

Oh, come on smurph, that's not even trying. Sandia Labs and other hands-on places have solid data for what solar panels produce versus location and rating. If you want them to preform all the tests again "on boats" beause there's some magical effect on the water, then you'll have to do what I did a couple of years ago, deploy a set of panels and take measurerments every 15 minutes and see what effect the BOAT has on anything.

The numbers are all out there for anyone who bothers to look for them. Sandia, universities, other countries, all the data are about the same.


----------



## smurphny (Feb 20, 2009)

hellosailor said:


> "Would like to see some non-theoretical, longitudinal data on the number of watt/hrs actually captured by solar panels on boats."
> 
> Oh, come on smurph, that's not even trying. Sandia Labs and other hands-on places have solid data for what solar panels produce versus location and rating. If you want them to preform all the tests again "on boats" beause there's some magical effect on the water, then you'll have to do what I did a couple of years ago, deploy a set of panels and take measurerments every 15 minutes and see what effect the BOAT has on anything.
> 
> The numbers are all out there for anyone who bothers to look for them. Sandia, universities, other countries, all the data are about the same.


Have done all the power consumption spreadsheets, including estimated times of use/recharging of things like SSB, computers, etc. Just installed a new Isotherm SP refrig. unit and a third solar panel and have closely figured everything again. I would just like to know how others, in the real world, have done as far as their initial calculations vs how it actually worked out. You know the old saying about "best laid plans." Sometimes all the data collecting and planning in the world turns out bad. Fukushima comes to mind


----------



## tdw (Oct 2, 2006)

I'd have thought that trying to get a really accurate gauge of solar panel output would be as useful as pissing into the wind. Seriously. The slightest variation in conditions and all your best laid plans have well and truly gang eft agleyed.

Now even if you did have an accurate idea of how much your panels were producing given e.g today's cloud cover for an hour an a half what would you seriously do about it ? Turn down the stereo for a couple of hours ? Come on now. (that doesn't deserve a smiley face but it wasn't meant to sound as terse as it might read.)

Reality is you want a damn good meter to tell how much you are producing right now and how much you are pulling. If on a bright sunny day that is not well into the plus side of the equation then either get more panels or turn something off cos once night falls you are in trouble. 

Trying to create a power usage plan in anything other than the vaguest of senses is possibly a bit of fun with spreadsheets but for mine that is about it.


----------



## hellosailor (Apr 11, 2006)

"Sometimes all the data collecting and planning in the world turns out bad."
SUre, but now you'ver changed the question. You're not interested in real output any more, you're interested in how well people have done their math. How well the rated consumption of ice boxes matches their actual consumption.
So you put a Watt's Up DC accumulating wattmeter on the big loads, and instead of debating what they draw, measure what they actually consume over 24 hours (etc) and multiply it out.
Watt's Up Meter - DC Inline

Or you start with a BMS that measures you entire load for the boat.

No biggie. And nothing to do with panel output, any more than it has to do with any other power source.


----------



## killarney_sailor (May 4, 2006)

Coming to this discussion rather late, but my 2 cents worth. We have 2 - 85w panels and a wind generator (Air Marine). Our batteries are about 800 amp/hours. We almost never have to run the engine or genset to just charge batteries. We might run the genset to power the watermaker and have the battery charger on, but we don't use the watermaker all that often. We have gone for weeks at anchor without fossil fuel use and made passages of a couple of weeks without needing to run the engine.

Considerations:
- My thought was that it would be either windy or sunny (sometimes both, rarely neither) where we were going to be sailing
- We are in the tropics where it tends to be both intensely sunny and quite windy. If we were back on Lake Ontario (much less wind and less intense sun) it would not be nearly as good.
- solar panels swing out from the boat's ralings so there is very little shading in most conditions; my understanding is that even the shadow of a stay can reduce output by 50% for poly-crystalline panels (I wanted mono-crystalline but could not find the right shape and size)
- We have seperate refrigerator and freezer so two Danfoss compressors; insulation was to a high standard for when the boat was built 30 years ago, by modern standards probably not
- All lights that are used for any length of time are LEDs; no electric appliances although we do tend to use iPad and notebook computers quite a bit.
- We are careful about wasting power.
- Forgot -we also have vane steering which saves a lot of amp/hours on a passage.


----------



## foggysail (Sep 19, 2010)

killarney_sailor said:


> Coming to this discussion rather late, but my 2 cents worth. We have 2 - 85w panels and a wind generator (Air Marine). Our batteries are about 800 amp/hours. We almost never have to run the engine or genset to just charge batteries. We might run the genset to power the watermaker and have the battery charger on, but we don't use the watermaker all that often. We have gone for weeks at anchor without fossil fuel use and made passages of a couple of weeks without needing to run the engine.
> 
> Considerations:
> - My thought was that it would be either windy or sunny (sometimes both, rarely neither) where we were going to be sailing
> ...


Killarney--

This stuff is all relatively new to me so I am no expert. I understood that a mono panel is far more sensitive to shadows than a poly. Am I mistaken?

Foggy


----------



## killarney_sailor (May 4, 2006)

I certainly am not an expert and it has been a few years since my research, but I thought it was monocrystalline that were better with shading. Can remember which company, but there was one type of mono panels that had cells on top and bottom. Thought it would be great sticking out from the rail with reflection on the bottom, but they were entirely the wrong size and shape.


----------



## smurphny (Feb 20, 2009)

hellosailor said:


> "Sometimes all the data collecting and planning in the world turns out bad."
> SUre, but now you'ver changed the question. You're not interested in real output any more, you're interested in how well people have done their math. How well the rated consumption of ice boxes matches their actual consumption.
> So you put a Watt's Up DC accumulating wattmeter on the big loads, and instead of debating what they draw, measure what they actually consume over 24 hours (etc) and multiply it out.
> Watt's Up Meter - DC Inline
> ...


That's what I mean by "longitudinal data" as I initially mentioned. I have not changed the question at all. Longitudinal data is that which gets collected over the long term in the *actual* use of any theory/hypothesis.


----------



## foggysail (Sep 19, 2010)

Is this the right thread to ask what others are doing for controllers? I purchased a junk so called MPPT controller from China that I am now attempting to sent back...more on that later. My options as I type include installing a reverse protection diode and just connect my two each 145 watt panels to the batteries with fuses and switches. The next option is to see if I can purchase an inexpensive pulse width modulated buck converter to get by the rest of the season.

So what are others doing?? OH-- the panel output voltages ar in the 21vdc range with current in the 8 ampere range/panel

Foggy


----------



## aeventyr60 (Jun 29, 2011)

I've had a Sunsaver 20 for several years, 2 bank capable.. They also make a 30 amps model as well.

Have heard of many, many problems with the MPPT controllers here at anchor in SE Asia as well as on my owners group.


----------



## hellosailor (Apr 11, 2006)

Foggy, before you install a protection diode, make sure your panels don't already have one built in. Or, check the "backflow" at night to see if what they consume is more than what the diode will cost you during the day, since there's some voltage loss across all diodes and all diode types are not equal.

I'd suggest one of the low-end Genasun MPPT controllers, they seem to do a good job at the lowest prices on the market for real MPPT controllers.


----------



## Cruisingdad (Jul 21, 2006)

foggysail said:


> Is this the right thread to ask what others are doing for controllers? I purchased a junk so called MPPT controller from China that I am now attempting to sent back...more on that later. My options as I type include installing a reverse protection diode and just connect my two each 145 watt panels to the batteries with fuses and switches. The next option is to see if I can purchase an inexpensive pulse width modulated buck converter to get by the rest of the season.
> 
> So what are others doing?? OH-- the panel output voltages ar in the 21vdc range with current in the 8 ampere range/panel
> 
> Foggy


I sure wouldnt be pumping 21 vdc into my batteries. Those panels are too large not to use a controller.

I use an Outback MX60 MPPT. Has worked flawless for years. Best thing I have installed. I know others have used Bluesky and I think Maine reccomened Morningstar but I have no first hand experience with them.

Brian


----------



## foggysail (Sep 19, 2010)

Cruisingdad (Brian)--

I know enough about these panels now to be dangerous........that even scares me! Now back to the 21vdc. I understand that the panels are current sources so the voltage reallys should not matter when working into a short or lower voltage unless their internal impedance , causes the panels to heat up.

The voltage drop will be across the panels, not the batteries because their internal resistance is too low. For example, if you charge a depleted battery and place say about 14vdc across its terminals, you would need to supply MANY amperes depending on the state of charge. If the battery was in the low 12vdc range and not sulfated, that thing could accept as much as 50 amperes DC but a panel can only supply 8 amperes on a good day.

Now if the battery is fully charged, that is another matter! It might enter a state of equalization.

Yes, I share your concern but my concern is with the panel not the battery unless the battery is left completely unattended. I might install the panels along with the wiring next week without using them to charge anything. I don't want to damage them before I even get to properly use them. Thanks for sharing your concerns--

Foggy


----------



## Cruisingdad (Jul 21, 2006)

foggysail said:


> Cruisingdad (Brian)--
> 
> I know enough about these panels now to be dangerous........that even scares me! Now back to the 21vdc. I understand that the panels are current sources so the voltage reallys should not matter when working into a short or lower voltage unless their internal impedance , causes the panels to heat up.
> 
> ...


I'd sure watch that water level and make sure tehy aren't bubbling. I wouldn't do it. Maine was sharing with me about a 10watt panel cooking a group 27. That sure shocked me as I have always seen them too small to matter. Your batteries are no doubt larger, but your panels are too.

I am curious what happens. Let me know.

Brian


----------



## Maine Sail (Jan 6, 2003)

foggysail said:


> Is this the right thread to ask what others are doing for controllers? I purchased a junk so called MPPT controller from China that I am now attempting to sent back...more on that later. My options as I type include installing a reverse protection diode and just connect my two each 145 watt panels to the batteries with fuses and switches. The next option is to see if I can purchase an inexpensive pulse width modulated buck converter to get by the rest of the season.
> 
> So what are others doing?? OH-- the panel output voltages ar in the 21vdc range with current in the 8 ampere range/panel
> 
> Foggy


You NEED a controller with those panels or you will cook the batteries when the get charged. Anything from Morningstar is good and even an inexpensive PWM would be FAR BETTER than nothing. The ProStar 15 is an excellent controller for the money.

*ProStar 15*

Search around you can likely find it for even less. Fried batteries will cost a lot more than a PWM controller....


----------



## Cruisingdad (Jul 21, 2006)

Maine Sail said:


> You NEED a controller with those panels or you will cook the batteries when the get charged. Anything from Morningstar is good and even an inexpensive PWM would be FAR BETTER than nothing. The ProStar 15 is an excellent controller for the money.
> 
> *ProStar 15*
> 
> Search around you can likely find it for even less. Fried batteries will cost a lot more than a PWM controller....


That's what I thought too. But hey, I am the same guy who said you don't need one for a 10w panel.

Brian


----------



## hellosailor (Apr 11, 2006)

"I know enough about these panels now to be dangerous"
Not yet but you're getting there.(G)

The voltage from the panels will vary with the load they are connected to, and a battery in different states of charge presents different loads. If the panels are small enough (compared to the battery capacity) you don't need a controller. But funny things happen, and a controller is cheap compared to new batteries or a fire. With nearly 300W of panels, you really want a controller. If you consider that an MPPT controller can give you 10% more power from your panels, ask yourself, what would an extra 30-40W panel cost you? Could you use that added power? If the answer is "yes", then an MPPT controller is worth buying. If you've got more power than you know what to do with, the answer is no.


----------



## tdw (Oct 2, 2006)

I've amended HelloSailors post to read "10% more power" I'm pretty certain he slipped on the 'shift' key.


----------



## Classic30 (Aug 29, 2007)

hellosailor said:


> The voltage from the panels will vary with the load they are connected to, and a battery in different states of charge presents different loads.


That's actually not correct, HS: The voltage from the panels will vary with the amount of sunlight falling on the cells. It's the *current* that varies with the load it's connected to.

That's why it's important to have a controller of some form on even the smallest of systems - since, unless a battery is used regularly it's still possible to overcharge ("boil") it during long summer days if directly connected to a solar panel.

Several of the smaller 'maintenance charging' panels on the market now have basic PWM controllers built-in - so it can become tricky for the layman to work out whether he needs a controller or not.


----------



## foggysail (Sep 19, 2010)

Come on now guys--- there are two things happening here. First was the discussions on risk where I believe the largest risk is with the panels, not the batteries IF THEY ARE WATCHED.

The second thing that folks are missing resides in one of my last sentence from above:

" I might install the panels along with the wiring next week without using them to charge anything. I don't want to damage them before I even get to properly use them. Thanks for sharing your concerns-- "

Years ago when I was an electrical design engineer there were many discussions about how a circuit would work by folks in both management and marketing. I learned that there is no way to ******** physics. Later in life as an engineering manager, I drove that base into younger engineers so often that one Christmas they handed a plaque to me that read "YOU CANNOT ******** THE CIRCUIT!"

So what does all this mean to our current discussion. I firmly believe the greatest risk are with the panels...because I am just learning this stuff rather than the batteries IF THE BATTERIES ARE WATCHED. There is little doubt in my mind that once they are fully charged, overcharging will result in them being forced into equalization along with boiling the water out of them...as someone just cautioned so overcharging must be prevented.

Now getting back to my YOU CANNNOT B----- gets to the heart of all this. Things happen!! Surprises happen!!! If the model is wrong things can smoke. That was why I backed away earlier by saying I might (if time permits) install teh panels along with the wiring BUT NO WAY do I intend to connect them to the batteries. There will be a controller of some type installed.

Now on the POS MPPT that was just delivered yesterday, I am banging on the seller for a refund. Yeah, I know, good luck. But the seller has a refund policy that does not mention that the item must be defective before it can be returned. Hey, I intend to squawk and squawk loudly to try forcing the issue. OK, I paid $80 for the POS that I refuse to connect to my new collectors. $80 is $80, it is far from ruining my life. I just resent getting screwed.

Foggy


----------



## foggysail (Sep 19, 2010)

Maine Sail said:


> You NEED a controller with those panels or you will cook the batteries when the get charged. Anything from Morningstar is good and even an inexpensive PWM would be FAR BETTER than nothing. The ProStar 15 is an excellent controller for the money.
> 
> *ProStar 15*
> 
> Search around you can likely find it for even less. Fried batteries will cost a lot more than a PWM controller....


OK, a good suggestion! I do have a concern although it is more so related to specs-. The Prostar 15 might be border line with panels rated at 8 amperes or so maximum. But then again most of the time the current will be less.

I am giving this controller serious consideration, I might order one in the morning. If so I will get the one without the meter. I just purchased a couple of hall current sensors that I need to build up. It needs a simple op amp plus a digital meter which I have several in my office. I prefer using I2C meters but for this application, a simple directed reading LCD volt meter should work fine with hall sensor.

MORE LATER--

Foggy


----------



## Noelex (Jan 23, 2008)

foggysail said:


> Yes, I share your concern but my concern is with the panel not the battery unless the battery is left completely unattended. I might install the panels along with the wiring next week without using them to charge anything. I don't want to damage them before I even get to properly use them. Thanks for sharing your concerns--
> 
> Foggy


Your panels can be directly connected to batteries in parallel safely. However you will need to monitor the battery voltage carefully and switch off one or both panels when the voltage climbs too high.

The Voc of 21v is not a factor. When connected to the batteries the voltage will be the battery voltage dependent on the input current. It will be an appropriate charging voltage untill the SOC of the batty climbs. When this happens you need to turn off a panel or turn on a load to keep the battery voltage appropriate. If you do not do this the battery voltage will rise to a dangerous level.

I have regulated systems like this on boats successfully for many years before controllers were effecient and affordable.

If you are going MPPT in partucular get a good one.
Outback are the best, but for a resonable cost look at the Rogue.


----------



## Maine Sail (Jan 6, 2003)

foggysail said:


> OK, a good suggestion! I do have a concern although it is more so related to specs-. The Prostar 15 might be border line with panels rated at 8 amperes or so maximum. But then again most of the time the current will be less.
> 
> I am giving this controller serious consideration, I might order one in the morning. If so I will get the one without the meter. I just purchased a couple of hall current sensors that I need to build up. It needs a simple op amp plus a digital meter which I have several in my office. I prefer using I2C meters but for this application, a simple directed reading LCD volt meter should work fine with hall sensor.
> 
> ...


They also make a ProStar 30....


----------



## foggysail (Sep 19, 2010)

I just ordered Prostar 15. More later--

Foggy


----------



## Noelex (Jan 23, 2008)

foggysail said:


> I just ordered Prostar 15. More later--
> 
> Foggy


If its 12v I am not sure that's big enough most 140w panels will produce close to 8A.
Edit:
I see you considered that, but ordered it anyway.

Most regulators will cope with a higher current and just limit to their maximimum rating. I never like to rely on this, but it won't cost you a lot of power. Check with the specifications to make sure, some just emit smoke when you go over their rating.


----------



## foggysail (Sep 19, 2010)

Noelex---

Sometimes you guys remind me of WIFEY!!!! WHAT DID YOU DO THAT FOR?????????

Yes, I did think about the 30 ampere unit, ruled it out because the cost was doubled at least where I looked previously.

I purchased the 15 ampere unit this morning from SolarHome.org. After reading your post and weighing how I made the trade off whereby I selected the 15 ampere unit, I rechecked the price of the 30 ampere unit at SolarHome where I placed my order this morning. Cost differences was $34.50! I quickly called the company who was wrapping my order for shipment and asked to upgrade to the 30.

Guess it was a wise move for the cost difference. What motivated me earlier to go with a 15 ampere controller was my thought that we most likely will rarely see enough sun to get the full 8 amperes output, If we did, weeell, so a couple of mosfets/diodes would just have to run hotter. But after reading your post I again thought, suppose I add another panel next year, then what?

Thanks Noel for posting a concern and yes, the voltage is 12 not 24.

Foggy


----------



## Noelex (Jan 23, 2008)

foggysail said:


> Noelex---
> 
> Sometimes you guys remind me of WIFEY!!!!


Well I am glad we are not sharing accommodation, otherwise I would be nervous 

I think you made the right decision.


----------



## DavidB.UK (Sep 11, 2011)

Hi everybody,

Thought this might be of interest and oddly relevant to this thread...


----------



## CRHODES (Aug 3, 2012)

Hi, I put in a system on my houseboat with 4 solar panels/6 batteries and the cost ran about $5000 US, it generates about 2.2 KW per day on a good day, which is enough to run the refrigerator and a few other things and the boat lights and equipment.

But the reality is, it can not do that consistently, I can go 3 days or so out on the hook with no generator but after that it becomes a game of how much sun do I get.

It would be possible if I had more solar panels and batteries to do more but at the moment till the costs on solar panels comes down a lot more it is not cost effective IMO.

Hope that helps happy to share more details if your interested.


----------



## foggysail (Sep 19, 2010)

Getting close! Tomorrow I should have my system up! I mentioned earlier that I purchased the Prostar 30 without the pricey meter. I just finished building a meter assembly that I stuffed into a plastic weather proof electrical box. I cut the blank cover to mount the meter which was calibrated to a 75mv shunt for 50 amperes. (edited--thanks to Hellosailor) I mounted the shunt on the rear of the box.

Finally I installed a jack that accommodates a 5.6 volt dc output from a transformer that will power the meter with about 5 vdc rather than the 12vdc that the meter is rated for. I found that the meter gets hot indicating the thing must have a zener diode in it for regulating. The dc output from the meter is......well it is really full wave rectified voltage with no filtering. Who cares if it works.

If anybody considers building their own metering unit, be careful to use a separate power supply...completely isolated from the supply whose current is being metered. Alsom the measuring is done on the return leg of the solar output. Enough of the simple basics.

Because the shunt can dissipate upwards to 2 watts, I have it mounted such that air can pass through the shunt for cooling. The box/shunt combo will mount tomorrow on plastic stand offs so the box will be about 3/4" off the wall giving clearance for the shunt proper.

Getting excited! We are taking next week off so it will be a good time for testing. My luck or lack of will probably see nothing but clouds and rain. More on that later. Another awe shucks! If I add another pair of panels, I will most likely exceed the rating for the Prostar. Time will tell. I have not seen any more of these panels on Amazon lately. 

CRRHODES--- You must have installed your panels sometime ago, I see that your setup cost about $5K. That is way beyond what I can afford at present. If these cheapo panels were not available, I would have no solar.

Your experience provides valuable insight on what to expect. Certainly I expect to run my genny when on anchor, I just don't want to run it to charge batteries unless I have to. I want my genny to provide energy for hot water, stove.... all the basics. OH, it will have to recharge my 24vdc battery bank, I can live with that.

More over the weekend!!!

Foggy


----------



## hellosailor (Apr 11, 2006)

"I wanted only 30 amperes to be displayed so I installed a divider across the shunt's output terminals"

foggy, I'm not quite waht you've done but can tell you this is NOT THE WAY TO DO IT.

The way meters and shunts are set up, it doesn't matter what range you want to read. All that matters is that the mv-per-display has been matched between them, and that you don't exceed the maximum amperage that the shunt can carry. Whether you want to read 10 amps, 25 amps, or 50 amps...if you have a meter and 50a shunt, they are set up the same way regardless.

I would strongly suggest that what you've done now is simply to distort all the readings. And, perhaps, that's related to the shunt overheating as well.

Some of the bargain stuff from China, which is SO attractively priced, almost scares me. The shunts are visibly different from the pricey domestic ones, and the all-in-one digital meter displays seem to vary quite widely in quality. (I've got two that never agree, even though they are supposedly calibrated and way exceed their display accuracy.)

50A shunt, 50A meter, put it back to the original configuration and it will read 30A scales just fine. Really.


----------



## foggysail (Sep 19, 2010)

hellosailor said:


> "I wanted only 30 amperes to be displayed so I installed a divider across the shunt's output terminals"
> 
> foggy, I'm not quite waht you've done but can tell you this is NOT THE WAY TO DO IT.
> 
> ...


GEEZ, I don't know what the heck I was thinking! Did this exercise late at night but thats a poor excuse. I scaled the 75mv for 30 amperes completely ignoring that the voltage drop of 75 mv depends on the current flow I through a resistor of value R. I just removed the divider, and you are embarrassingly correct, it will read 30 amperes if the shunt is correctly calibrated and of course, current flow is 30 amperes. Thanks for pointing out my screw up, I just deleted that mess from the previous post.

As to the stuff for China-- you pays you money, you takes you chance. Something as simple as a meter/shunt in a non critical application is fine.

Foggy


----------



## hellosailor (Apr 11, 2006)

You got seduced by Ohm's Flaw. ;-)


----------



## foggysail (Sep 19, 2010)

hellosailor said:


> You got seduced by Ohm's Flaw. ;-)


That was so bad---- ugh!


----------



## davidpm (Oct 22, 2007)

paintpollz said:


> Thanks for the response BLjones.
> 
> When I get my first boat, hopefully within 5 years, I'll be a weekender and daysailor.


Five years!!!!
In five years we will probably have 100 amp batteries the size of a coke can and solar panel paint.

Everyone and their nephew is working on battery and solar tech.

Five years!!!!


----------

