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Comment by barbegal | Hacker News Reader

Are there any technical details available for this system? The linked article doesn't do a good job of explaining how it works or how much impact it will have.

Assuming the boat can harness 10% of the wave's energy, wave power in the Philippines is more like 10kW per meter of wave length captured on average so that equates to ~1kW per metre of wave. Let's assume this boat can capture roughly 10m of wave then that is an average power generation of ~10kW or ~ 10hp. A boat of this size will probably have 500+ hp engines so a boost of 10hp won't have a huge amount of impact.

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Found another article with more numbers: "The ship’s “independent multi-engine technology at minimum 3000hp drive shaft sea class” is combined with a wave energy device that’s capable of generating up to 300kw/h of energy, Salvador explains." https://news.mongabay.com/2020/04/a-wave-powered-ferry-aims-...

300kw/h is a nonsensical unit in this case. kw*h would be energy, but kw alone would be the proper unit to compare to the 3000hp drive shaft.

300 kilowatt-hours per hour

From the Wikipedia article Hybrid Trimaran (Philippine ship) [1]:

> Waves gathered from the vessel's outriggers will drive the double action hydraulic pumps which will generate power for the ship.

It sounds like the "outriggers" are the two outer hulls of the trimaran.

[1] https://en.wikipedia.org/wiki/Hybrid_Trimaran_(Philippine_sh...

This is exactly the kind of order-of-magnitude estimation that I was looking for in the article. Where did you get the wave energy numbers?

I got them from this map https://commons.m.wikimedia.org/wiki/File:World_wave_energy_...

Probably this[1] is the same boat? [1]: https://en.wikipedia.org/wiki/Hybrid_Trimaran_(Philippine_sh...

Here's a quick estimate: The potential energy of the wave will go like mass x gravitational acceleration x height. If the depth (front to back) of the wave is about 1 meter and the height is also about 1 M, then per meter of wave we get

M g h

g = 10 m / s^2;

M = 1 g / cm^3 = 10^6 g / m^3 = 10^3 kg / m^3;

H = 1 m

MGH ~ 10^4 Joules per meter

If a wave comes every 10 seconds —> 10^3 joules / sec, not far from what this person quoted. We need to add to this the kinetic energy, which might double it. Playing with the other parameters we can get close to what the parent quoted.

Just a note: at sea, when the ratio of wave height to wave length exceeds 0.17, the wave will break, so a 1m by 1m is impossibly steep.

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