# Solar Power for catalina 27



## mbaillie (Mar 13, 2013)

I am looking to purchase some solar panels to power my cat27. I currently have 2 deep cycle batteries on board. I am new to the solar world and am looking for some advice on what to get to make sure my batteries stay charged.


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## Faster (Sep 13, 2005)

Interesting things in the solar side of things - walk-on and flexible panels that will make mounting them less of an issue..

Steveston Marine offers the Ganz line, flat thin panels you can walk on, reasonable size and if you're not running a fridge they may provide enough to keep you going, esp if you're using LED lighting.

Pacific Yacht Systems (?) offers a line of very flexible panels that can be sewn/snapped/velcroed/zippered onto dodgers or biminis.

Understand that solar is not always reliable in these parts, but summer in Desolation is going to be alright. The problem has always been how to mount them efficiently without turning the boat into a bit of fugly.

You'll also need a solar charge controller to ensure you don't overdo things on a bright sunny day. None of this is cheap, of course.... but the newer panels will/may need less structure that will reduce the overall cost.

Do a power budget.. figure out your daily usage on average and see if there's a panel that can supply that in a 10-12 hour stretch of sun...or less...


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## Rhys05 (Aug 22, 2012)

I'm probably going to be getting something like this: 




Combined with this: 




to keep my battery charged on my S2 7.9 which is berthed at a powerless dock with a motor with an alternator that is integrated into the flywheel that doesn't charge (BMW D7). From my back of the envelope calculations it appears that 50W should be sufficient for me to start my motor, run a (small) chartplotter/fishfinder, some autopilot (tiller pilot), LED lights, etc. for a good period of time cruising away from power. YMMV


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## ABH3 Boyer (Sep 27, 2012)

I currently use a solar pannel to charge my system. I dont ever plug in and I go out at least 2 to 3 times a week in the height of the season. I always come back to my boat with a full charge next time I go. Currently I'm installing a 55#thrust electric motor to use to get me in and out of the harbor. Looking for the 125watt pannel to recharge my battery in time for the next trip. My pannel has a glass face so I have to be careful about where I mount it but other than that there has been no problems going into the 2nd season of using it.


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## Skipper Jer (Aug 26, 2008)

If you don't tell use what equipment and how long you use said equipment then any advice we give would be akin to "Here, this piece of rope is long enough." Do you intend to tie your alternator into the charging system? Do you sail at night, have LED nav lights,
LED cabin lights? Got an electric windlass and anchor a lot? Run a depth sounder, chart plotter, radar, VHF, AIS, frig/freezer ? Any idea how much area you have to mount the panels?


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## mbaillie (Mar 13, 2013)

marine stereo, gps, depth/fish finder, running lights, outboard electric starter

enough power to go away for a weekend and still be able to start up my boat


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## norahs arc (Jan 23, 2013)

I used a 64 watt panel last year and it covered my usage most of the time. I use the lights a lot, small GPS, VHF, autotiller, and a bilge pump which runs a few times per day (Shaft seal drips a bit too much - on spring repair list.) Never had any problems.
Putting refrigation aboard this year and will add a second panel. Your choice of a 50W and controller sounds adaquate. The nice thing about solar is you can add to it without changing much as long as your controller and cables can the added amperage.


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## Faster (Sep 13, 2005)

No fridge, and reasonable sunshine a 40-50W panel should more than keep up. Good deep cycle batteries should be able to keep up with those light loads for some time.


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## tommays (Sep 9, 2008)

Installing A Small Marine Solar System Photo Gallery by Compass Marine at pbase.com

Start with Mainsails guides as you will get a free lesson on what works and why it works










You want one of these










And a good panel like a 40 watt sunwize does well on my 29' with two group 27s


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## jameswilson29 (Aug 15, 2009)

The two deep cycle batteries are adequately maintained by the 40 watt panel on my Pearson 28, which you can see from all sides in this video:






The electrical load includes an autopilot, bilge pump, navigation lights, and engine starter.


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## mdbee (May 2, 2007)

You are right, the OP needs to do a power audit. But isn't 10 - 12 hours a bit optimistic for sunlight hours that far north? The charts I have (for Canada) show about half of that. Are those charts off? 

Another issue, although the new panels can be walked on, you also need to keep them out of shadows. That usually means you need to mount them somewhere that you normally wouldn't be walking on them anyway. Mounting them on a dodger or bimini is pretty clean but also usually a problem with the shadows.



Faster said:


> Interesting things in the solar side of things - walk-on and flexible panels that will make mounting them less of an issue..
> 
> Steveston Marine offers the Ganz line, flat thin panels you can walk on, reasonable size and if you're not running a fridge they may provide enough to keep you going, esp if you're using LED lighting.
> 
> ...


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## Maine Sail (Jan 6, 2003)

mdbee said:


> Another issue, although the new panels can be walked on, you also need to keep them out of shadows. That usually means you need to mount them somewhere that you normally wouldn't be walking on them anyway. Mounting them on a dodger or bimini is pretty clean but also usually a problem with the shadows.


This is the big problem with "walkable" panels on sail boats. At deck level there are often a ton of shading issues. Couple that with a small wire that needs to go through the deck somewhere and a junction box that sticks up above the panel and an expensive panel can be destroyed in one swift trip/kick..

Mounting on dodgers or on the deck under the boom are also terrible places for "performance" for the shade you noted.

One trick I use when an owner is dead set on mounting on a dodger is to use port & starboard 40W Solbian panels and then each panel gets is own GVB-4 boost controller. The panels are strategically positioned to be as far outboard on the dodger as is possible and allow for a proper fit. This allows each controller to maximize the performance of each panel during shading events. A bimini or davits or stern pole are clearly the best locations but not all boats have bimini's or davits.

I have two customers that are adding bimini's this year simply because of solar. The selling points of a bimini made no sense for them prior to solar but when you add the solar to the bimini it makes for a nice package.


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## Faster (Sep 13, 2005)

mdbee said:


> You are right, the OP needs to do a power audit. But isn't 10 - 12 hours a bit optimistic for sunlight hours that far north? The charts I have (for Canada) show about half of that. Are those charts off?


In June/July we can get sun above the horizon (away from the mountains) for that long at least... but you're right, we're not talking full efficiency over that time, and it certainly doesn't happen every day.... In any event the OP doesn't seem to have particularly heavy loads and will likely do well with a minimal solar setup.

The shading is, of course, a major issue, and one that must be balanced against any aesthetics that one might consider when choosing where/how to install. MS's two panel - two controller plan sounds brilliant.


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## tommays (Sep 9, 2008)

On my boat with a meter telling the truth the 40 watt/genasun combo starts putting out useful amounts of power 3/10 amp at 8 am ? and peaks out at 2.5 amps at noon 

I keep a simple boat with Led cabin lights and have not had issues on weekend trips after one full season of use 

It works so well after the boat was moved home for the winter I put the panel back on and used the cabin lights all winter without any issues as the winter storage area has a southern exposure


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## mdbee (May 2, 2007)

I know it's hard to put a figure on it but how much difference do you think running two controllers makes? And how much more efficient are the Mppt controllers (vs PWM) for panels of this smaller size?



Maine Sail said:


> This is the big problem with "walkable" panels on sail boats. At deck level there are often a ton of shading issues. Couple that with a small wire that needs to go through the deck somewhere and a junction box that sticks up above the panel and an expensive panel can be destroyed in one swift trip/kick..
> 
> Mounting on dodgers or on the deck under the boom are also terrible places for "performance" for the shade you noted.
> 
> ...


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## Maine Sail (Jan 6, 2003)

mdbee said:


> I know it's hard to put a figure on it but how much difference do you think running two controllers makes? And how much more efficient are the Mppt controllers (vs PWM) for panels of this smaller size?


For those particular panels, the Solbian 40W, there is only one controller. These are 8V panels and use a "boost" controller that takes the low voltage and boosts it to charging voltages. The controller is specially made by Genasun and works amazingly well...

For a typical 40W panel a Genasun MPPT is quite a bit more efficient. Unlike some MPPT's they are specifically designed for lower wattage panels where you use one controller per panel to maximize MPPT tracking.. You can expect about 8-15% more per day on average...


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## PetePearson (Apr 2, 2013)

I am looking to purchase some solar panels to power my cat27. I currently have 2 deep cycle batteries on board. I am new to the solar world and am looking for some advice on what to get to make sure my batteries stay charged.[/quote]

I use a Morningstar "SunSaver Duo" solar charge control regulator that can charge two batteries independently. It charges one then switches to the other once fully charged. I'm not sure if you can force it to charge Batt #1 or Batt#2.
can handle up to 25 Amps and has a digital display. Has worked well for 5 years.


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## Alex W (Nov 1, 2012)

I use a setup similar to the one suggested by Maine Sail and tommays. It's works well for me.

A 30w to 40w panel (mono-crystalline for the best efficiency) is about $100 through eBay or Amazon. The Genasun MPPT controller is about $60 or $70. Mounting hardware actually ends up being the most expensive thing to sort out. On a tiller boat a cheap option is to use some good quality clamps mounted at the midpoint on the panel, with the panel mounted on the back rail. That works best with smaller (lighter) panels. It's not meant to illustrate it, but this is how I had the panel installed on my Catalina 25:









Clamps are visible here in the upper left:









That Catalina 25 doesn't have shore power and it's batteries are primarily charged by the 20 watt panel.

On a wheel boat this doesn't work so well because the panel intrudes into the cockpit space right about where the helms person wants to sit. Maine Sail has a guide on how he mounts panels that fixes that issue, but requires over $100 in hardware:
Installing A Small Marine Solar System Photo Gallery by Compass Marine at pbase.com

That is what I've done on my Pearson 28-2 (not yet wired when this was taken):









That is a 30 watt panel and it puts out a little over 2 amps at noon on a sunny day.

Adding a battery monitor system (http://www.pbase.com/mainecruising/battery_monitor) will give you a lot of insight into your power consumption. I didn't have one on the Catalina 25 and was flying blind but with way more battery capacity (2 group 24, so 150 amp hours) than I needed for an all LED boat. I added one to my Pearson and it's really helpful to understand power demands and battery state.


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## asdf38 (Jul 7, 2010)

This was my solution this year.

I picked up a Genasun MPPT sort of spur of the moment when I saw that it was only $50 and added a 20W panel from Amazon for another $50. Seeing how expensive rail hardware was I went my own way.

First I made fancy PVC lumber clamps. But then after some additional thought I decided to go simply with cable ties. Two of the ties go through the frame and the others go through the PVC lumber support bar running the length of the panel. I needed something to support it in the middle that was flush with the frame. The PVC bar is attached to the panel just with 3M VHB tape. It's basically free and was easy. At some point I'm going to reverse the ties so the latch part isn't visible.

The perko connector in the deck is spaced off the deck with a PVC lumber donut spacer. (I love/hate those perko connectors - they don't prevent momentary reverse polarity connections so I added series schottky diode to protect the controller from being hit with the panel voltage in reverse).


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## mitiempo (Sep 19, 2008)

PetePearson said:


> I use a Morningstar "SunSaver Duo" solar charge control regulator that can charge two batteries independently. It charges one then switches to the other once fully charged. I'm not sure if you can force it to charge Batt #1 or Batt#2.
> can handle up to 25 Amps and has a digital display. Has worked well for 5 years.


Actually the SunSaver Duo charges both banks at the same time. You can set charging priority to either 50/50 or 90/10 by adjusting the dip switches. 90/10 makes the most sense for a house bank/start bank arrangement on a boat. If set as 90/10 it will charge both banks with 90% going to house bank and 10% to the start battery. After the house bank is fully charged it will divert more current to the start battery if needed. If it is either engine dedicated or an emergency battery it will be charged long before the house bank is fully charged however.


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## AdamLein (Nov 6, 2007)

Alex W said:


> Clamps are visible here in the upper left:


Where'd you get these clamps?


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## tommays (Sep 9, 2008)

Sailrite has a nice selection of hardware


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## mitiempo (Sep 19, 2008)

I use Magma bbq mounts that allow you to adjust the panel's angle in seconds and lock them in place at any angle. They are more expensive than the ones pictured above but work very well.


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## Alex W (Nov 1, 2012)

AdamLein said:


> Where'd you get these clamps?


They are stocked at Fisheries Supply. They are also standard items on a lot of rail-mount hardware (Dickinson uses them for their BBQs, my Jim-Buoy life ring also uses them).

They are distributed by Sea-Dog:
Sea-Dog : Quality Marine, Industrial and Rigging Hardware

The plastic is pretty soft, so they don't have the highest clamping power. They really only work for this if used in a balanced way. They are inexpensive though.


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## asdf38 (Jul 7, 2010)

I made decent rail mounts out of PVC lumber before deciding not to use them. Cut a square or rectangle, 1" hole saw the middle, saw it in half. Bolt the two halves back together around the rail.

Though if I had known that those rail mounts were available for $10 I would have gone for those.


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## JoeLena (May 14, 2012)

Alex W said:


> That is what I've done on my Pearson 28-2 (not yet wired when this was taken):
> 
> 
> 
> ...


Alex, what about the support and clamps on your Pearson, where can I get that support? Looks nice and clean. And which model clamps?

Very nice!


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## Alex W (Nov 1, 2012)

The clamps are from Taylor Made. Look at Maine Sail's article referenced above.

The strut is a Sea Dog Line hatch strut, it cost about $20. Like everything Sea Dog Line the quality is low and it is getting rust spots after 3 months.


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