The energy is not free, since the solar panels cost money and don't last forever. Even at optimistic prices, it's still something like 0.03 USD/kWh. Install them on a boat and they have to deal with constant vibrations, humid conditions, seagulls shitting all over them, etc etc etc.

I used to work on ships and almost everything constantly breaks down without constant maintenance. I bet it would be much cheaper to put the solar panels on land and charge the ship when it's in port.

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reactordev an hour ago | parent | next [-]

I sailed around the world on a sailboat with solar. I know. It’s still better than none at all.

The energy is free. To capture it costs a little bit of money.

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vlovich123 an hour ago | parent [-]

There’s something funny to me about taking your experience with solar on a small sailboat and extrapolating this to a commercial ferry that would need a very large solar installation that’s funny to me. Something tells me the experience isn’t transferable.

	▲	reactordev 9 minutes ago \| parent [-]
		The point isn’t to power the main drive, the point is to preserve energy used elsewhere on the ship. My experience sailing and dealing with vessels from 30ft to 180ft give me a perspective that you probably don’t. Providing solar panels along the roof would give the ship a few KWh of power that would otherwise be drawing from the main batteries. This would extend the range of the ship by 5-10%.

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teiferer 2 hours ago | parent | prev [-]

That may all be true, but there are other benefits that could make it worth it. For example it could be, in theory, self-sufficient forever if something else breaks down making it unable to maneuver. Then you can at least sit in the middle of the sea and have your heating and cooking and desalination working until you repair the propulsion.

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padjo 2 hours ago | parent [-]

You already have MWh of batteries for that.

	▲	reactordev an hour ago \| parent [-]
		No you don’t because after a few days broken down, they are drained without solar.