Originally published at: WaveSwell drawn sustainable electricity from the sea's natural motion | Boing Boing
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This will change the world, I think.
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Bender: Neat! yet gormless armchair engineer asks: why not have two generator turbines, one for the blow out cycle of the wave (lower level in the schematic) as well as suck back (upper)? double the energy capture?
(answers own question: turbines make lousy one way valves, maybe?)
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Wind! the energy source so nice, we capture it twice!
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So it really is about the motion in the ocean.
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I had a friend in engineering school, he a grad student while I was undergrad, doing research on wave energy conversion in the early 90s. I’ve kept my eye on the field since and am thrilled to see working mechanisms deployed. It’s been a LONG time coming.
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Wave power has been threatening to do so for a long time. For some reason (capitalism, eh?) it has not taken off. (Tempted to say the idea has been floated on many occasions but seems to sink without trace every time.)
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Well no resource is infinitely scalable. If a section of coastline had enough of these concentrated together then the waves that reach the shore would be greatly diminished, and I’d hate to see that. Who would want to deprive the dolphins of one of their great pleasures?
But hopefully this works out to be practical in moderation. Having all the moving parts above water is a big help for maintenance but still, any installation at the ocean can be hard to keep running.
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Oregon State University has been working on this for years. https://today.oregonstate.edu/news/dept-energy-awards-25-million-wave-energy-technology-testing-oregon-state-facility
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I watched the entire video in the hopes that I would learn how the energy generated by this system is actually fed into the grid. Considering that these ships are mobile, that seems like a tricky problem to solve. Perhaps there is an engineer who can provide a bit of detail on this?
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The demonstration unit can be refloated and moved if needed but isn’t normally a floating ship once placed. One of the videos showed a cable going to shore.
Looks like larger scale future installations would likely be concrete, permanent installations like a breakwater.
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Glad to hear this is up and running.
The technology is relatively simple and has been known for a very long time; oscillating water columns displacing air were used in the 19th Century to power horns on marine navigation buoys and the first navigation buoy using the principle to drive a generator was as long ago as the 1940s.
A 500kW installation (albeit onshore) was tested for a number of years on Islay off the West Coast of Scotland. This was then used to develop a much larger unit in the Bay of Biscay off of Spain.
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Thanks for the info. The concept certainly makes sense, but I didn’t realize that the plan was to install permanent units. I got stuck on the floating and moveable aspect of the demo unit. Seems like there would be some serious location and permitting issues, as well as the engineering problems to solve. And there would have to be a lot of them to make any kind of a dent.
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My very uneducated guess: The turbine creates power by “stealing” it from the airstream. But if you steal momentum from the thrust of the air flow at both inhalation and exhalation, maybe you’d end up with an overall diminished power output yet have the cost of installing and maintaining two turbines?
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Yep, like @Otherbrother said, it’s a cable running from the wave-energy platform back to shore and into the grid there. Which means they won’t be willy nilly moving these around despite the ease of mobility; they’ll still have to be set up in places where the onshore infrastructure can handle them.
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The videos from the company just mention that it greatly simplifies turbine design. If the main structure is simple concrete then I would assume that the turbine is the most expensive part to build.
They didn’t mention this but I thought it was interesting that the turbine is powered by the vacuum created by the swell dropping back down, and the intake sucks in air from outside. I’ll bet that means that the air is a lot dryer that way, which is probably better for the turbine components. Maybe quieter for people nearby too.
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An old friend has been at this since the '80s
Ocean Wave Energy Conversion at owec.com
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I was wondering about the floating buoys if a big storm came by. Less so if the installations are permanently anchored concrete, but a big storm swell can still make hash out of almost any breakwater.
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It really has. I asked a marine engineer, who explained that wave power faces hurdles that solar and wind don’t. First and foremost: the moving, energy-capturing parts are usually in dirty sea water (dirty as in silty, kelp-y, fish-y, barnacle-y), salt air, and other nautical headaches. Building something affordable that will reliably extract enough energy under those conditions is … challenging. Most of the time, you’ll get a ton more lifetime kW-hours per dollar from a solar panel or wind turbine.
So on the one hand, the slow development of wave power sounds like people are just being cheap again.
On the other hand, if you had a choice to spend a hundred million dollars on renewable energy, would you pick a 100 MW solar farm, or a 5 MW wave-power site? Remembering that renewable power displaces fossil fuel power on the grid.
At this stage, the low-hanging fruit is still in solar. That’ll change when we have so much solar we don’t need much more power in the daytime.
ETA: this one keeps the moving parts out of the water, but the moving parts still pick up a lot of salt spray - compare their location with an offshore wind turbine, which keeps its hub well above the ocean. I can also see why this approach hasn’t received much attention; extracting energy from air is a lot less efficient than from water, so there’d be less interest in trying it this way. What we have here is a tiny wind turbine that is only able to pull a fraction of the power that an immersed water turbine could - theoretically - pull from the same water column.
It’s not terrible; but it looks like not much bang-per-buck when you look at how much power is actually in a wave.
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True, probably a lot less salt spray in the vacuum intake air too. Salt is nasty.
