Solar Panels - Looks Like a Good Buy

Larry H · Posted: Mon Feb 11, 2008 1:39 am Post subject:

Bob,

I think the way to decide is:

Multiply the amps consumed by each device by the hours of use. That equals amp-hours for each device. Add up the amp hours. That is daily usage. Add 15-20% for recharging inefficiency. This gives amp hours needed per day.

Solar panels might produce for 6 hours per day. So divide the amp hours needed per day by 6 to obtain the charging amps required.

So 100(example) A-H required per day + 15%= 115 A-H divided by 6 hours = 19 amps output. 19 amps x 12 volts = 228 watts.

I would think that two 100 watt panels that run at 18 volts open circuit should provide the needed power in the summer.

However, most C-Dorys run their motors after several days at anchor so actual A-H need may be less.

Consider that if you installed some LED lights for anchor or cabin the A-H needed could be reduced.

Dora~Jean · Posted: Mon Feb 11, 2008 2:45 am Post subject:

FWIW, found this ad in today's Harbor Freight paper, probably Taiwanese for sure, no diodes I suspect (they can be added), needs a regulator--who knows it might be in the 'kit', this is a set of three 15W panels, don't know dimensions or thickness, sorry.

Discovery · Posted: Mon Feb 11, 2008 9:18 am Post subject:

Our solar panel setup

6 x 15 watt panels, total of 90 watts. They are from Northern Tool, cost $80.00 each on sale. The charge controller is a MMPT type boost controller. The cost was about $100.00 from eBay.

The charge controller is the larger panel in the center of the overhead.
We also use solar panels on our 5th wheel trailer (2 x 120 watts) and on our truck camper ( 1 x 75 watts).

cpf3 · Posted: Mon Feb 11, 2008 10:46 am Post subject: Solar Source

As full-time RVers, we have a large solar set-up for our RV. This includes four 75 watt pannels, a charge controller, and four deep-cycle golf cart batteries. But, we probably use a lot more power for 'stuff' than the average C-Dory operator.

We used RV Solar Electric's web site and worksheet to compute our power needs....http://www.rvsolarelectric.com/

It's a good place to start when trying to figure out how to set up a solar system. They offer a free catalog that includes a section on system design and equipment.

Chuck Flanagan

Charlie one shoe · Posted: Mon Feb 11, 2008 3:45 pm Post subject: Solar

I think the most important thing to consider when buying a solar panel is the warranty and will the company stand behind it. Just because it's cheap to purchase doesn't always mean it's the best buy.

Solar panels can fail. I had a Kyocera KC 120 that failed after 7 years and was replaced 100% under Kyocera's warranty, in fact they upgraded mine to a KC 130 panel. When the panel failed I just called the warranty dept. and they sent me the new one with an RA# to return the old one.

I have my panel setup on my " off the grid " cabin in the mountain's with a charge controller, inverter, and 4 deep cycle batteries. I use 12 volts for lights and the inverter for dish TV, computer, ect. I'm sold on solar!!

I don't have solar on my C-Dory but after reading this post I'm going to check it out.

Charlie