Important Disclaimer - I am not a certified marine electrician. The below was developed with the paid help of several folks who do this for a living. Unless you are actually trained to do this type of design, attempting on your own could result in serious injury or death. The voltages coming through the Solar Controllers will kill you. The amount of power stored in the batteries will easily weld steel if short circuited. Please seek qualified help before designing something like this and if you are unsure of how to install, the university of you tube is full of advice that can kill you or leave you with an unsafe system.

Solar Power on SV Unladen Swallow 2

Solar power in areas where electricity is readily available does not generally make sense economically with the payback period often equaling that of the cost of the installation.

However, when we are talking about full-time live-aboard boats. The argument can be made that solar power is actually worth the effort, especially if you want to travel further afield and plan to stay in the subtropics and tropics and not have to worry about refueling as often. For comparison on the original boat, we had 2060w of solar charging 1200AH of 12VDC Lithium batteries. Our daily energy budget was about 10KW and on average, we watched the sunset with nearly full batteries. Over the course of 2 years, we had to use the main engine (with the 170A Balmar High Output Alternator) as a Generator 3 times. So solar definitely worked out for us.

Solar power can easily recharge a modest electrical bank after a night of living on the boat. A larger battery bank with more demand will require a larger solar array to keep up. We did learn that as much as we don't care for Air Conditioning, it's necessary to get a good night's sleep when the wind dies. So we are going for more battery and more solar this time around.

• Voltage (in) Total W Output A @ 24VDC MPPT Size

• A 104.4 1800 75.00 150/85

• B 69.6 1200 50.00 150/60

• C 120 1000 41.67 150/45

• D 96 650 27.08 100/30