SV Delos has a great video on power generation methods https://www.youtube.com/watch?v=Osh1ljtgnSU https://www.youtube.com/watch?v=Osh1ljtgnSU . It is a larger

SV Delos has a great video on power generation methods https://www.youtube.com/watch?v=Osh1ljtgnSU https://www.youtube.com/watch?v=Osh1ljtgnSU . It is a larger boat (58ft?) that is lived on full time and they use a combination of solar, wind and fossil fuel for energy. In another video (can't find it offhand) they talk about propeller driven generation and how it isn't a great solution for them. Propeller driven generation is expensive, it requires another hole in the bottom of the boat, requires maintenance (marine growth), it only works when the boat is moving, and its power ultimately comes from the wind or fossil fuels. Why not get the energy from the wind directly using a wind generator? It's cheap, effectively maintenance free, runs whenever the wind blows even at anchor, and if you're running the engines, more efficient to generate electricity using the generator. They have the wind generators mounted above and slightly off the back of the boat, where they are out of the way and remain permanently. They mention their energy generation mix is about 10% wind, 25% fossil, and the rest solar, using 3 panels. Their numbers were generated in low latitudes where solar insolation is quite high, so kind of the sweet spot for solar. I imagine further north wind generation is comparatively more useful. I know more recently they have added some flexible panels on the canopy which added a bit more capacity. I'm guessing that Peltier generation is not going to be effective for anything more than fractions of a watt. The studies I see online all work with larger temperature differentials, like > 50 deg C, which you aren't going to find anything close to in a thermocline layer. To work with a smaller temperature differential you would need to increase surface area immensely, and water is a high-drag environment. I found it interesting that one of the more power-hungry things on a sailboat is fresh water. Watermakers consume 15-30 Wh of energy per gallon, and a boat will need about 20 gallons per day per person. For a 4 person boat, that 80 gallons requires 80*15=1200Wh each day. Most sailboats will use the generator to fill up the freshwater tank because they don't have enough solar capacity.