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Power

Blowhole Wave Energy Generator Exceeds Expectations In 12-Month Test (newatlas.com) 85

Posted by BeauHD from the promising-tech dept.
Wave Swell Energy's remarkable UniWave 200 is a sea platform that uses an artificial blowhole formation to create air pressure changes that drive a turbine and feed energy back to shore. After a year of testing, the company reports excellent results. New Atlas reports: As we've discussed before, the UniWave system is a floating device that can be towed to any coastal location and connected to the local energy grid. It's designed so that wave swells force water into a specially designed concrete chamber, pressurizing the air in the chamber and forcing it through an outlet valve. Then as the water recedes, it generates a powerful vacuum, which sucks air in through a turbine at the top and generates electricity that's fed into the grid via a cable. As a result, it draws energy from the entire column of water that enters its chamber, a fact the team says makes it more efficient than wave energy devices that only harvest energy from the surface or the sea floor.

[...] A 200-kW test platform was installed last year off King Island, facing the notoriously rough seas of Bass Strait, which separates the island state of Tasmania from the mainland of Australia. There, it's been contributing reliable clean energy to the island's microgrid around the clock for a full 12 months. The WSE team has made a few live tweaks to the design during operation, improving its performance beyond original expectations. "We set out to prove that Wave Swell's wave energy converter technology could supply electricity to a grid in a range of wave conditions, and we have done that," said WSE CEO Paul Geason in a press release. "One key achievement has been to deliver real-world results in Tasmanian ocean conditions to complement the AMC test modeling. In some instances, the performance of our technology in the ocean has exceeded expectations due to the lessons we've learnt through the project, technological improvements and the refinements we have made over the course of the year." "Our team is excited to have achieved a rate of conversion from wave power to electricity at an average of 45 to 50% in a wide range of wave conditions," he continues. "This is a vast improvement on past devices and shows that the moment has arrived for wave power to sit alongside wind, solar and energy storage as part of a modern energy mix."

The King Island platform will remain in place at least until the end of 2022, and the company is now gearing up to go into production. "Having proven our device can survive the toughest conditions the Southern Ocean and Bass Strait can throw at it, and deliver grid compliant electricity, our priority now shifts to commercializing the technology," said Gleason. "For Wave Swell this means ensuring the market embraces the WSE technology and units are deployed to deliver utility scale clean electricity to mainland grids around the world."
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Blowhole Wave Energy Generator Exceeds Expectations In 12-Month Test More

Blowhole Wave Energy Generator Exceeds Expectations In 12-Month Test

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  • Same link twice? Both useless. It does not give much information about the technology nor about the mentioned report, just "renewable blaa blaa" bullshit and images of Earth you can get from any commercial.

    I want video about how the machine itself works, or table that compares different technologies.

  • Here's the article that they should have linked. (Score:5, Informative)

    by robbak ( 775424 ) on Tuesday August 02, 2022 @03:29AM (#62754924) Homepage

    Look like they messed up, and included the same old youtube link twice, and omitted the link to the actual article.

    Thankfully, it wasn't hard to find -

    https://newatlas.com/energy/bl... [newatlas.com]

    • Thanks for finding that article. The video on that link is far more informative from a technical perspective.

  • wave break that generates power (Score:5, Informative)

    by vivian ( 156520 ) on Tuesday August 02, 2022 @03:47AM (#62754964)

    Looking at the location where this is being tested, where there is a wave break wall close by, this looks like a great solution to use in such areas to both lessen the incoming wave energy, and harvest that energy.

    If that small unit can generate 200kW, they only need another 30 of them to generate all the power that King Island uses (about 6GW), though obviously they would want to diversify their renewable generation sources so all their eggs aren't in one basket.

    The Uniwave is 22m long by 14m wide, so that would be about 420m of them parked side by side, which looking at the size of it would be less than the length of the seawall that it's parked next to at Grassy harbor.
    https://www.google.com/maps/pl... [google.com]

    The additional shelter that they would provide should actually help support more marine life too.
    There's more details in the development application about the devices and where they were tested.
    https://kingisland.tas.gov.au/... [tas.gov.au]

    I hope they can build and maintain these cost effectively.
    This trial version cost 12.3m, which makes it price out at $61/kw with an expected 20 year lifespan. They have a lot to do to get that cost down to compete with wind and solar, or fossil fuels. Hopefully they can build these modules in bulk and reduce the cost per unit with manufacturing at scale.

    • Re:wave break that generates power (Score:4, Insightful)

      by vivian ( 156520 ) on Tuesday August 02, 2022 @03:56AM (#62754976)

      Actually I miscalculated. It's $61 per watt.
      Compared to nuclear which is about $5.40.watt, wind which is about $1.30/watt and solar which is about $0.61 per watt. of course wind and solar have a lower equivalent full time power rating than waves or nuclear, but even so it's a big gap.

      • I assume that 12.3m includes R&D for building the first one.

        There's no way it should cost 12m each to build them in series, it's a block of concrete with a turbine at the top.

        • There's no way it should cost 12m each to build them in series, it's a block of concrete with a turbine at the top.

          To be fair, it's a floating block of concrete with a turbine at the top. :-)

          According to the video, his setup only passes air through the turbine as the water (inside the cavity) goes down. I saw another video where the turbine is powered by air moving in both directions. Apparently, this (the former) setup is simpler but, I'm guessing, generates less power. How much less I don't know, but imagine the reduced power generation is offset by simpler turbine design and maintenance.

          • To be fair, it's a floating block of concrete with a turbine at the top. :-)

            I think it's actually resting on the sea floor and not floating.

          • Correct, the article said that the turbine lasts much longer from reduced sea spray ingestion, and it's also much simpler because it doesn't need to be reversible.

          • The single action design would blow less salt spray through the turbine. Having less restriction on the upstroke would get a higher water column for the down stroke.

            So I can see a couple of advantages to the single action design. How it plays out in practice is a good question.

    • Re: (Score:3, Informative)

      by vivian ( 156520 )

      I should have looked up all this info and put it in the one post but I keep finding more stuff...
      here's a great paper from CSIRO on projected cost per kw.

      https://arena.gov.au/assets/20... [arena.gov.au]

      On page 27 (with a nice graph) they seem to indicate that around a total cumulative capacity of about 1GW worth of total installations, the levelised cost/kw should be about where Solar and wind are at, and reduce further as even more is installed.

      Those guys are a lot better at maths than me - here's hoping they got it righ

    • Re:wave break that generates power (Score:5, Informative)

      by lorinc ( 2470890 ) on Tuesday August 02, 2022 @05:03AM (#62755036) Homepage Journal

      200kW is the peak power. Your link mentions 50kW as a more likely operating point, and the original article of the summary mentions 40kW.

      The UniWave200 has a maximum output of 200 kW, but at the Grassy site it will produce an
      average of 50 kW

      (https://kingisland.tas.gov.au/wp-content/uploads/DA-2019-18-Wave-Energy-Converter-Grassy-Harbour.pdf [tas.gov.au], page 4)

      "It's important to stress that the demonstration at King Island was not about producing high volumes of electricity," he responds. "Rather, it was to prove the capabilities of our technology in a variety of wave conditions. The results have met and at times exceeded our expectations. As an example, when the unit is generating 40 kW of power in reasonable wave conditions, you could extrapolate the amount of energy to be in the order of 1MWh in a 24 hour period."

      (https://newatlas.com/energy/blowhole-wave-energy-generator/ [newatlas.com])

      So it's more something like 2km of coastline for ~2000 inhabitants, which does not really scale that well. It's nice to turn seawalls into something that serves 2 purposes, but it's not going to solve any energy problem. As a comparison, in the Netherlands the coastal protection system length is ~350km long, so this system would provide electricity for ~350 000 Dutch people (although they may use less energy than Australians), or 2% of the population. Nice, but not game changing.

      • Re: (Score:2)

        by raynet ( 51803 )

        When to mention extrapolating for 24h generation, it sounds like they have not managed to run it continuously for 24h. Otherwise they would have said something like, in average it generates X MWh daily, or something like that.

    • you also miscalculated, it takes 30 THOUSAND of those to produce 6GW

      • you also miscalculated, it takes 30 THOUSAND of those to produce 6GW

        Where did this 6GW number come from, there are only 1500 people on that island, are they all bit coin miners?

        • Re: (Score:1)

          by guruevi ( 827432 )

          The average household uses 8000-10,000 kWh per year and rising due to increased demand for electric cars, electric heat etc. Businesses, factories (I'm assuming there's at least some fishery on the island) etc use a lot more.

          This device reportedly can generate just 40 kW of power on average, basically if they find a way of storing the fluctuations, it could be a generator for 2 houses, they'll need 2 for a grocery store and about 5-10 for the local fishery. That gives us 2,000 of these contraptions at the v

          • Even if they scaled it up 2-5x (which would be hard, given the physics and it barely fits on a boat today)

            It never goes on a boat anyway...

            The UniWave is constructed of concrete with steel flotation pontoons. The unit will be built in Launceston and towed to the site near Grassy Harbour where the pontoons will be flooded and the unit will sink into position. The UniWave sits on the sea floor under its own weight of approximately 1000 tonnes.

          • I suspect there was a unit error in play. Basically the island doesn't consume an average of 6GW of instantaneous power, they consume 6GWh/year :

            9,000kWh/year/household, assuming an average household size of two, translates to about 7GWh/year total. That's in the right ballpark, and with only 1500 people I doubt they have a lot of additional heavy industry.

            The alternative, that they *do* consume 6GW, would mean they consume 6e6*365*24/1500 = 35GWh/year/person, or about 8,000x more than normal. They'd have

          • Right, so that's 6GWh per year, based on 1500 people being around 600 households, not 6GW... Units, people, units. It's 0.7MW average.
    • If there is only 2000 people on the island as stated and they each use 3kW then the total usage is 6MW not 6GW. 120 machines at 50kW each would do the job.

    • I hope they can build and maintain these cost effectively.

      I hope they can build & maintain them in an ecologically sound way. Lining the coasts of the USA (or the world) with what are effectively large concrete blocks has got to have some impact....

      • You do know that sea walls, jettys, and other coastal erosion protection is built all the time, right? Using concrete and large quarried rock?

        These could easily be integrated into those efforts to still manage coastal erosion, but also produce some clean energy at the same time.

        • Do note that your seawalls, jetties, etc are NOT covering the entire coast. This, if it works as intended, will eventually cover the entire coast....

          • That doesn't have to happen. There's more options than "build it everywhere we can" and "build it nowhere".

            • If it's as good as they say, then it will, inevitably, be built everywhere.

              Unless we decide that only The Right People deserve the cheap electricity.

    • Does King Island use 6 GW or 6 MW? 30 X 0.2.MW is not 6000 MW.

      The article left out how they level the pulses. Reciprocating steam engines used a big flywheel. Electrically you use a capacitor. How slow can the waves be before the output starts pulsing too much?

      It's the best wave energy gadget I've seen yet. It at least tries to keep the moving parts out of the salt water/sand/barnacles.

  • Couldn't they use two unidirectional turbines, so they take advantage of both directions, while keeping the turbines simple? I suppose for demonstration purposes, it's cheaper to have one turbine, but for production use, two turbines could double the output, while sharing the rest of the structure.

    • If you have a turbine driven from the air inside the column, then the turbine will be ingesting a lot of water spray. Air drawn back into the column should be a lot dryer.

      • Also: Resistance on the inflow means the chamber will be receiving some positive buoyancy on each inflow, I wonder if part of this design is to help prevent this box from slowly migrating like an unbalanced washing machine.

    • Re: (Score:3)

      by eth1 ( 94901 )

      Couldn't they use two unidirectional turbines, so they take advantage of both directions, while keeping the turbines simple?
      I suppose for demonstration purposes, it's cheaper to have one turbine, but for production use, two turbines could double the output, while sharing the rest of the structure.

      You wouldn't actually need two turbines per unit if you're building them in a line. The turbines could be placed between the blowholes, with alternating turbines being driven by vacuum and compressed air, which is contributed by both units adjacent to the turbines. That way you'd only need one turbine per unit, plus one.

    • You can do it with one turbine just takes two extra valves. Is the reduced lifespan of turbine worth it though? A matter of experiment that.

  • That's a lot of concrete and too much sand (Score:5, Interesting)

    by echo123 ( 1266692 ) on Tuesday August 02, 2022 @06:18AM (#62755128)
    Sand is a precious commodity and the world is running out of it [cnbc.com]. Desert sand isn't good enough for concrete because it is too smooth, only river and beach sand will do. The amount of sand required for this technology to scale efficiently must be a large concern.

    • I've read this story as well when it made the rounds but the total lack of details makes it highly suspicious to me that this is a real issue and not just hand-wringing over nothing / click-bait.

      71% of the planet is covered by oceans, much of which have water-eroded sand at the bottom. I'd guess the amount of water-eroded sand humans have ever used is a tiny fraction of a percent of the planet's total. Maybe some areas are running out of easily-accessible sand - but where there's demand there's always a way

    • Re: (Score:2)

      by dargaud ( 518470 )
      There are many other things you can add to cement to make concrete, but they haven't been investigated fully because sand is (was?) so much cheaper. I've seen tests with carbone nanotubes and the resulting strength was insane.

      • I've seen tests with carbone nanotubes and the resulting strength was insane.

        I'm guessing the insane strength was much less insane than the price.

    • You could do it without sand by using seacrete, and as a bonus, it reduces oceanic acidification by pulling carbon directly out of the water. All you need to make a seacrete structure is a metal cage and an electric current (and of course, the sea.) It's commonly done with alternator-based windmills made out of junk.

    • Re: (Score:1)

      by thosdot ( 659245 )

      Sand is a precious commodity and ... The amount of sand required for this technology to scale efficiently must be a large concern.

      If you can anchor the unit to the sea floor, or a rccky coastline, you don't need anywhere near as much concrete - the test version uses so much because it's only test, and they want it to sit there without being moved around unless they do it. A permanently located one could use much less, for instance by casting it with voids which are later filled with ballast.

  • Thorium.

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