I am wonder about the feasability of a seastead making 10amps at 120vac, 24 hours per day, without primary use of an internal combustion powered generator, and without batteries making up the bulk of power at night. On 120vac, 10amps can run a small size of everything i can think of in a modern home, just not all of it at the same time. If you have a power bill from the electric company, this is the same as 864 kwh, or at $0.13/hwh it’s about a $120 bill’s worth.
I am not ruling out the use of a generator of some flavor, depending on how one uses the power, but lets restrict it to ~30 gallons per month, and do heat recovery on it too. Some things may need turning by an engine, not necessarily a generator. Going to land to get the fuel may cost you more than the price of the fuel itself.
Naturally, first choice in sunny weather would be the 1800 watts of solar panels on the porch roof.
In deep water, off continental shelves, i am thinking thermal-solar-boosted OTEC, with a 1000ft cold water line. It’s a 24-7 type of power supply, but hard to say how much power is affordable to build.
At night, 10amps at 120v for 10 hours is 16 hp-hours. I can’t say with any certainty what else can make this much power at night. Not that you would need it all at night, but if you did, for internet, computers, radar, radios, lights, refridge, and hvac, it’s a hefty constant load.
Your practical ideas?