ROFL. Comapring a 400 watt solar panel, which might put out 20-30,000 wat-hours per day, to a 5? 10? kw diesel genset that can put out the same power in just two hours instead of 24?
Yes, the fuel costs money. But you're cleverly ignoring the question of how much power is needed in one day, and whether your 400W solar panel could even make a DENT in that "requirement" including a fridge, computer, and other devices. And of course, since you can't have sun all the time, you'll also have to upsize your battery banks to make sure you can carry through 2-3 sunless days, when the genset wouldn't need that.
Not that solar can't be the answer--if you properly phrase the question. In the past 3 years the prices for solar panels have plummeted but again, depending on what someone's energy budget is, sometimes you simply can't fit enough of them onto a boat. In secure locations, unshaded.
This is what I've figured thru previous posts, from a weekender's
standpoint, that doesn't even have a boat yet
The price of fuel compared to the the energy created to provide luxuries on the water is minimal.
The initial cost for solar, while not incredibly expensive, coupled with the living adjustments to maintain battery power, seems like a greater loss in living comfort, when, primarly relying on a solar system for power regeneration.
I think it would be beneficial to combine the two, but then again, is it really necessary to have 2 systems? It seems for a weekender, no. But a cruiser, definitely.