Cheapest wave power yet: boats that go fishing for electricity

Okay, so this right here is a pretty terrible rendering. But the idea that it represents is a good one: by turning ships into mobile wave energy harvesters, you can cheaply and efficiently go out to the ocean and haul a big fat load of electricity back to your hungry customers. It's like fishing, except for power.

This idea of mobile wave energy harvesting is a simple one: you put wave energy harvesters on boats, send those boats out to sea, they sit out there for about a day riding the swell and charging their batteries, and then they come back in to shore and offload their electrical cargo. There's no complex and expensive undersea construction, no need for cables to run back to shore (at $1 million per mile), you can move the generators around easily, and best of all, we can retrofit ships to do this relatively cheaply.

Each 150 foot ship (like the concept pictured above) would be able to harvest about one megawatt of energy per hour, which is enough to power about a thousand homes. It would store up 20 megawatts in giant batteries over 20 hours at sea under average conditions, and then head back to port and pump all of that power into the grid. Once the transfer is complete, the generator can go back out again and fish up another load. Get enough ships together, and you can harvest as much power as you need, since it's not like you're going to use up all the waves or anything.

Testing of scale models suggests that power produced this way could be as cheap as $0.15 per kilowatt-hour, which is half the cost of solar and between half and a third the cost of conventional (stationary) wave harvesters. The residential consumers in the U.S. pay on average anywhere from $0.09 to $0.16 per kilowatt-hour, so this could definitely be a viable method for coastal areas. And besides, even if it does cost a smidge more, you're getting clean, renewable, eco-friendly power, and isn't that worth paying just a little extra for?

FHCMI, via New Scientist

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