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United Kingdom Power Technology

Scotland Builds Power Farms of the Future Under the Sea 216

HughPickens.com writes "The Pentland Firth is a raw, stormy sound between the Scottish mainland and the Orkney Islands, known for some of the world's fastest flowing marine waters. Daily tides here reach 11 miles per hour, and can go as high as 18 – a breakneck current that's the reason people are describing Scotland as the Saudi Arabia of tidal power. Now Megan Garber reports in The Atlantic that a new tidal power plant, to be installed off the Scottish coast aims to make the Scotland a world leader for turning sea flow into electricity. Underwater windmills, the BBC notes, have the benefit of invisibility—a common objection to wind turbines being how unsightly they are to human eyes. Undersea turbines also benefit from the fact that tides are predictable in ways that winds are not: You know how much power you're generating, basically, on any given day. The tidal currents are also completely carbon-free and since sea water is 832 times denser than air, a 5 knot ocean current has more kinetic energy than a 350 km/h wind.

MeyGen will face a challenge in that work: The turbines are incredibly difficult to install. The Pentland Firth is a harsh environment to begin with; complicating matters is the fact that the turbines can be installed only at the deepest of ocean depths so as not to disrupt the paths of ships on the surface. They also need to be installed in bays or headlands, where tidal flows are at their most intense. It is an unbelievably harsh environment in which to build anything, let alone manage a vast fleet of tidal machines beneath the waves. If each Hammerfest machine delivers its advertised 1MW of power, then you need 1,000 of them to hope to match the output of a typical gas or coal-fired power station. "The real aim," says Keith Anderson, "is to establish the predictability which you get with tidal power, and to feed that into the energy mix which includes the less predictable sources like wind or wave. The whole point of this device is to test that it can produce power, and we believe it can, and to show it's robust and can be maintained."
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Scotland Builds Power Farms of the Future Under the Sea

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  • These turbines will kill all the fishies!

    • I'd be more concerned about what small rocks and shellfish will do to the turbines. I'd imagine these things make enough noise to warn fish that isn't suicidally curious..

    • Re:Oh no! (Score:5, Funny)

      by Mr D from 63 ( 3395377 ) on Monday November 03, 2014 @01:39PM (#48302401)

      These turbines will kill all the fishies!

      But, this is the power source "of the future". So, as long as the fish are in the present, they are safe.

    • Re:Oh no! (Score:4, Funny)

      by houstonbofh ( 602064 ) on Monday November 03, 2014 @02:16PM (#48302813)

      These turbines will kill all the fishies!

      No, it will kill SOME of the fishes. And fead other fishes not dumb enough to get killed in a turbine.

      And I, for one, salute our new hyper intelegent fish overloards.

    • Pre-sliced sushi - whats the problem with that?
  • by rahvin112 ( 446269 ) on Monday November 03, 2014 @01:25PM (#48302233)

    Any underwater installation will face the same challenges as Tidal power, that is what to do about the biologicals. The ocean is teaming with life and it will literally grow on anything. What do you do when the entire underwater "windmill" is covered in barnacles? Every underwater generation scheme is toasted by the life problem. None of them are tolerant of all the sea life that will grow on and around the facility.

    • by MrL0G1C ( 867445 ) on Monday November 03, 2014 @01:42PM (#48302467) Journal

      Every underwater generation scheme is toasted by the life problem. None of them are tolerant of all the sea life that will grow on and around the facility.

      And that's why ocean going super-tankers where never possible.(sarc'). Doesn't stop the Thames Barrier and Dams/hydro power across the world does it.

      What do you do when the entire underwater "windmill" is covered in barnacles?

      How about: Clean them off.

      • by rahvin112 ( 446269 ) on Monday November 03, 2014 @03:01PM (#48303243)

        So how do you clean them? Do you send divers down several hundred feet to hand scrape a moving blade? Do you haul them to the surface? Do you haul them to dry dock like they do ships every 10 years?

        Ships constantly scrape while at sea and are typically brought into dry dock every 10 years for a thorough cleaning with high pressure / high temperature cleaning. This isn't a ship, it's a stationary bit of metal underwater in some of the coldest water on the planet. It's not going to be spinning fast enough to puree living mater like a ships propeller and they get fouled and have to be cleaned by hand all the time.

        Everything in water ends up covered in living matter. This isn't a problem for stationary non-moving/non-mechanical objects. It is a serious problem for anything mechanical that for example needs to spin freely. Every tidal or current generating scheme requires moving parts under water and that's a problem for anything that isn't operating at puree speed.

        • If it's enormous and heavy, it won't have to spin fast to crush anything that tries to wedge itself in somewhere, and then grind it into a fine paste.
        • So how do you clean them? Do you send divers down several hundred feet to hand scrape a moving blade?

          Isn't that what robots are for?

          If that's too hard there are things that could be done with heat, current, toxins, anchors/winches, enclosing the moving parts inside a closed environment (propeller in the current sounds suboptimal) - when your machines don't have to move around the world, some limitations go away.

          I'm no professional diver, but even just wreck diving in strong surges is quite a challenge - I c

        • by Thud457 ( 234763 )
          Robots.
          Hundreds of barnacle-scrapping robots per unit.
          Sounds like a business opportunity to me.

          Awww crap, somebody else [dvice.com] beat me to it.
      • Since the idea of both tidal and wave energy has been promoted since OPEC price disruptions of the 1970s (see Severn Barrage) but has never been successfully implemented (due to economic costs, largely managing brine and mollusks), either A) they have figured out a simple solution, or 2) they came up with a more novel solution, more interesting than the article suggests, or C) this is /.
        • by MrL0G1C ( 867445 )

          It seems that a large scale project is viable, with a conservative large insurance company investing in a tidal power scheme:
          UK Renewables May Be Turning The Tide [oilprice.com]

          Large scheme, scalable to GW's of power, cheaper than off-shore wind, able to provide electricity on-demand, something that solar and wind aren't so good at.

    • Does this apply to places with strong tidal currents? I imagine it must be difficult to attach to a surface when you're being pulled by a strong current.
      • by itzly ( 3699663 )
        On the other hand, a stationary object in a strong current is an ideal place to sit there and catch food, so it's likely that sea life has evolved to take hold in such place.
        • Not even sea life can ignore the laws of physics, though. ;-) It's been my understanding that barnacles need some time to attach properly, and in some places, I simply don't see it very likely that they'd have a chance.
    • by jenningsthecat ( 1525947 ) on Monday November 03, 2014 @02:08PM (#48302715)

      The ocean is teaming with life and it will literally grow on anything. What do you do when the entire underwater "windmill" is covered in barnacles? Every underwater generation scheme is toasted by the life problem.

      Cover every bit of metal with an insulating coating, then print, deposit, or laminate gold or platinum electrodes on the surfaces. Connect 'odd' electrodes in one branch of a circuit, 'even' electrodes in another, than apply an alternating voltage between them. The seawater completes the circuit. Unless a life form lands on the metal - then IT completes the circuit. I suspect most life forms will not like a continuous alternating current passing through them, and will 'move to greener pastures". Overall generating efficiency will be reduced, but probably not as much as it would be by barnacles, etc.

      I'm not a marine biologist and I don't know if this would work - just tossing the idea out there.

    • by AmiMoJo ( 196126 ) *

      They are experimenting with different coatings that reduce the amount of biological fouling. It's true that this problem is not solved yet, but it's worth developing the technology to overcome it because of the potentially massive gains possible.

      • The costs of such anti biological technology has sunk every under water power generation scheme. The floating tidal generators were fouled by kelp and ocean debris. The ones that took in water with the waves got clogged. And the lifetime on these systems wasn't even 6 months before they were fouled.

        Ships are coated in horribly toxic materials and even so they have to be scraped near constantly at sea and most are pulled into dry dock every 10 years for a full high pressure high temperature cleaning. How do

        • Do you send out drivers or haul them back to the surface and clean them? Both are wickedly expensive

          They have to be tethered to something anyway (fixed power cable) - why not allow them to anchor/de-anchor so they can be pulled up to a cleaning ship? Why would that add a tremendous cost to each unit? No need for a winch on each unit - that can be on the ship. The one moving part would be some sort of attachment mechanism - the motor for that can even be on the umbilical from the ship. I'm assuming these

    • Every underwater generation scheme is toasted by the life problem. None of them are tolerant of all the sea life that will grow on and around the facility.

      Simple: coat everything in paint with Transuranic waste additives!

    • The ocean is teaming with life....

      GO TEAM LIFE!

      Sorry, couldn't resist...

    • I don't see the problem here. Just put a straw downstream from the turbines and you have instant cioppino.

  • by NotDrWho ( 3543773 ) on Monday November 03, 2014 @01:28PM (#48302289)

    My grandpa always said that Scotsmen and water just don't mix. But then again, maybe he just meant TRUE Scotsmen.

  • EROEI? (Score:3, Interesting)

    by mrflash818 ( 226638 ) on Monday November 03, 2014 @01:29PM (#48302299) Homepage Journal

    What is going to be the Energy Return On Energy Invested?

    How expensive to install and maintain, as sea water is much harsher than having a wind turbine in atmosphere?

    What is the expected lifetime of each generation unit?

    • The Rance power station in France has been in working order for some forty-odd years, and apparently is cheap enough to run. Having said that, that one is a dam (but the turbines of course run on sea water).
      • i'm guessing that dams of any kind are going to generate more power than free standing turbines.

      • by afidel ( 530433 )

        Interesting, it looks like the Rance build costs (~$650m in current dollars for ~540GWhrs of annual output) have been recovered in under 40 years and the operating costs are lower than nuclear (1.8c/kWhr vs 2.5c/kWhr). Decommissioning costs will be lower than nuclear obviously, and safe operating life is probably longer. So it would seem in areas with high average tidal flow it's pretty obvious that it's worth at least exploring.

    • by AmiMoJo ( 196126 ) *

      It's an R&D project designed to determine those things. It even says so right in the summary.

    • With wind it is actually solar radiation that does the most damage. That is less of a problem under water.
  • by Anonymous Coward on Monday November 03, 2014 @01:34PM (#48302349)

    A typical (500 megawatt) coal plant burns 1.4 million tons of coal each year. As of 2012, there are 572 operational coal plants in the U.S. with an average capacity of 547 megawatts.

    http://www.ucsusa.org/clean_energy/coalvswind/c01.html#.VFe77y0wJIo

    I don't know where the poster got their numbers from, but an average coal plant is around 500 megawatts not 1000. This would imply that you only need 500 of the hammerfest machines to equal a powerplant. They should probably be more careful in the future to use accurate data.

    • by houstonbofh ( 602064 ) on Monday November 03, 2014 @02:23PM (#48302893)
      Hey, wait a second. When did we start using "facts" in environmental debates?
    • I don't know where the poster got their numbers from, but an average coal plant is around 500 megawatts not 1000. This would imply that you only need 500 of the hammerfest machines to equal a powerplant.

      That thought crossed my mind too. But a 1 MW tidal generator is not going to generate 1 MW. On average it's going to generate closer to 0.64 MW (2/pi if you do the integral of a sinusoudal current flowrate) before taking into account biological fouling, maintenance, etc. So TFS is still correct that it's

      • by es330td ( 964170 )

        So TFS is still correct that it's about a 1000:1 ratio.

        Absent evidence to the contrary he got lucky and does not get credit for it.

      • Re: (Score:3, Informative)

        by RandomAdam ( 1837998 )
        You assume that a 1MW generator won't generate 1MW....based on what exactly? If the electrical part of the generator is able to produce 1MW then you size the mechanical parts to supply the required power to spin the generator appropriately.

        Yes there are times of dead tide, twice a day for about an hour, which are very predictable. Actual practical efficiencies are another story; how are the mechanical parts of the system going to be fouled, how long it will take etc...

        Also your 2/pi number is irrelev
    • I don't know where the poster got their numbers from, but an average coal plant is around 500 megawatts not 1000.

      I'm not a Scottish or European person. Perhaps the average coal plant in Europe is around 1000 megawatts.

    • Did you check if UK coal plants are the same as US with regards to output (as this is a project in Scotland)?
  • um, no (Score:2, Interesting)

    The tidal currents are also completely carbon-free

    This myth needs to end. There is no such thing as a "Carbon free" energy source. Some are worse than others obviously. But very large, very heavy materials will need to be used to construct those turbines. Mines will get dug, parts will get shipped, maintenance will need to occur.

    This doesn't have Tidal on it but you can bet it will fall somewhere between wind and solar.
    http://www.scientificamerican.... [scientificamerican.com]

    Solar is the real eye opener and should serve as a lesson on blindly trusting hype and "What seems obvious

    • You point to that figure and say that solar panels are terrible for the environment. Yes, apparently solar panels need more silver (and other metals) than other generation techniques, however, that doesn't mean that an ABSOLUTELY LARGE amount of silver is going to have to be provided.

      Most power generation techniques don't need silver barely at all, so "relative to the current mix",yes, solar is going to need lots. That DOES NOT necessarily mean that supplying that amount of silver is going to cause widespread environmental degradation in the same way that coal DOES.

      Also, solar power, once in place, doesn't require megatonnes of fuel like coal, oil, and gas do. (In that order, I guess.)

      That figure doesn't DIRECTLY give insight into what energy mix is best for the environment, you can't have any hope of that unless you also compare fuel inputs per kwh generated as well, and other factors.

      • We've been using silver for photography in massive amounts. We can use the same silver production to make solar panels now. Not to mention the fact that recovering metallic silver from panels is no more difficult than recovering silver compounds from used photographic materials, and we've been doing that anyway.
    • Re:um, no (Score:5, Funny)

      by CrimsonAvenger ( 580665 ) on Monday November 03, 2014 @01:56PM (#48302605)

      hydroelectric damns

      Dams.

      I realize some people like to curse dams, but still....

      • by Shoten ( 260439 )

        hydroelectric damns

        Dams.

        I realize some people like to curse dams, but still....

        Whereas, when I hear someone referring to those "hydroelectric fucks," it seems they are speaking about the Canadians...

    • by itzly ( 3699663 )
      You assume that the metals used in solar panels cannot be recycled.
    • The only reason there's no such thing as carbon free energy sources is because so many human activities depend on sources of energy that aren't carbon free. Technically we need carbon based energy sources to make wind turbines, but if we switched over to 100% wind generation (assuming it was possible), then we could make wind turbines and produce wind energy in a carbon free way. Obviously nothing can be carbon free right now, because even if the maintenance guy drives a diesel truck to fix it, it's not ab
    • The only way in which tidal currents are "non-carbon-free" is the extent to which CO2 is dissolved in sea water. ;-) The plant of course will have some carbon costs associated with it, but if sufficient energy gets produced, it won't matter. You could even use some of the extra energy to recapture it some time after building it. I don't get where you got that "oil doesn't look so horrible" when virtually every single CO2 molecule generated by burning oil in practice escapes into the air. As far as solar pan
    • http://www.scientificamerican.... [scientificamerican.com]

      Solar is the real eye opener and should serve as a lesson on blindly trusting hype and "What seems obvious." Solar panels are terrible for the environment,

      It's always important to remember that there's no such thing as free energy. That said, the linked graph doesn't say anything about solar being "terrible for the environment", only that other sources of electricity consumes* very little silver compared to solar (as Scientific American also notes in the graph). Importantly, it does not show how that use compares to e.g. worldwide silver use.

      * "consumes"? "wastes"? "produces as a byproduct"? Pretty sure that oil energy (or biomass!) doesn't consume uranium, e

    • If you can exceed 1:1 power output to maintenance, you can create oil from air. Then you can use that oil as a fuel source.
      • by afidel ( 530433 )

        Why on gods green earth would you use Fischer–Tropsch when you can do biodiesel at a much higher EROEI? The only really good use of Fischer–Tropsch I've seen is using a nuclear power plant on a carrier to produce AvGas for the jet fleet to eliminate the long tail supply line, and the navy didn't think it enough of an advantage to include an extra set of power plants in the current generation of carriers (expected to be produced through 2050 and in the fleet through 2100) to do the production.

    • Nuclear is the least damaging to the environment [...]

      As long as nothing goes wrong.

  • by David_Hart ( 1184661 ) on Monday November 03, 2014 @01:56PM (#48302601)

    The Bay of Fundy has the most powerful tides in the world. "The estimated potential of the Fundy region alone is upwards of 60,000 megawatts of energy, of which up to 2,500 megawatts may be safely extracted."

    Nova Scotia had a trail running in Nov. 2009 with OpenHydro and they ended up having to remove their turbine when, "20 days later, all 12 turbine rotor blades were destroyed by tidal flows that were two and a half times stronger than for what the turbine was designed."

    http://www.cbc.ca/news/canada/... [www.cbc.ca]

  • , a 5 knot ocean current has more kinetic energy than a 350 km/h wind.

    . If each Hammerfest machine delivers its advertised 1MW of power,

    With such large amounts of energy why oh why are they pissing about with such tiny turbines? Modern wind turbines are 6MW+, some hydro power turbines are over 700MW each. Are they trying to destroy the financial viability of the project with unimaginative small scale thinking?

    • by itzly ( 3699663 )
      Small turbines are easier and cheaper to install. Not a bad choice when there are already enough challenges. After some experience with small turbines, they can work on bigger ones. They didn't start with 6MW+ wind turbines either.
      • by MrL0G1C ( 867445 )

        And of course the depth of the area the turbine is being put in is a major factor, unlike wind turbines which keep getting bigger and higher. I'm just impatient, I get sick of hearing about sub 100MW renewable energy projects, ramp it up already!

    • by Shoten ( 260439 ) on Monday November 03, 2014 @03:15PM (#48303367)

      , a 5 knot ocean current has more kinetic energy than a 350 km/h wind.

      . If each Hammerfest machine delivers its advertised 1MW of power,

      With such large amounts of energy why oh why are they pissing about with such tiny turbines? Modern wind turbines are 6MW+, some hydro power turbines are over 700MW each. Are they trying to destroy the financial viability of the project with unimaginative small scale thinking?

      Scroll up to the post just above yours, referencing the Bay of Fundy and its failed turbine approach. Big turbines go boom when water move too fast, it turns out. Smaller turbines are made of materials with similar strength, but have much less force exerted on them under extreme tides. And, unlike a hydro power turbine, they can't force the full flow of the water to pass exclusively through the turbine here; a turbine that attempted the same level of energy harvesting would instead build up a head of backpressure, and the water would flow around it. That is, until the tide ripped the thing off the floor of the bay.

  • by MrKevvy ( 85565 ) on Monday November 03, 2014 @01:57PM (#48302607)

    re: "since sea water is 832 times denser than air, a 5 knot ocean current has more kinetic energy than a 350 km/h wind"

    Kinetic energy is an integration of the linear mv dv so equals 1/2mv^2 (whereas momentum is the simple product mv.)

    So let's set the mass of a volume of wind at 1 and the mass of the same volume of sea water at 832 units.

    The kinetic energy of the wind @ 350km/h = 1/2 * 1 * 350^2 = 61,250 units
    The kinetic energy of the water @ 5 knots = 1/2 * 832 * (5 * 1.852)^2 = 35,671 units (1 knot = 1.852 km/hr)

    • That's ignoring the linear effect of the velocity on the mass flow. I'd argue that when speaking about currents, this can't be ignored. For five knots of water flow, for a unit of cross-section (1 m^2), it's about 2.6 tons/s per at 3.3 joules per kg, which is 8.6 kw per square meter. On the other hand, the 350 km/h wind would be 117 kg/s at 4700 joules per kg, therefore 550 kw per square meter.
    • by itzly ( 3699663 )
      Maybe it helps that water isn't compressible.
  • If each Hammerfest machine delivers its advertised 1MW of power, then you need 1,000 of them to hope to match the output of a typical gas or coal-fired power station.

    No, that's not "typical" at all. The largest coal-fired plants are 1-2GW; currently I believe there is no gas-fired plant anywhere in the world that is 1GW. So it would be more accurate to claim 200-500, while 1,000 is pure exaggeration.

    • by dj245 ( 732906 )

      If each Hammerfest machine delivers its advertised 1MW of power, then you need 1,000 of them to hope to match the output of a typical gas or coal-fired power station.

      No, that's not "typical" at all. The largest coal-fired plants are 1-2GW; currently I believe there is no gas-fired plant anywhere in the world that is 1GW. So it would be more accurate to claim 200-500, while 1,000 is pure exaggeration.

      Well, that depends on how you count. A single coal unit really maxes out at about 1200-1300MW, although these are pretty rare. More typical is a unit in the size range of 400-900MW. Note that the viability point is somewhere 150-300MW right now in the US for a coal plant. Anything smaller will have a hard time making money right now given economies of scale and the low low price of natural gas. Multiple small units still aren't cost-effective. You need the big machine to make money nowadays in the US.

  • Easy! (Score:5, Funny)

    by jbmartin6 ( 1232050 ) on Monday November 03, 2014 @02:11PM (#48302745)
    Hard to build? Just build it somewhere else, tie some cement blocks to it, and heave it overboard! See, this is why I should be running everything.
  • Underwater windmills, the BBC notes, have the benefit of invisibility—a common objection to wind turbines being how unsightly they are to human eyes.

    Beauty in the eye of the beholder I guess but I've always found wind turbines to be beautiful. I could seriously watch them for hours.

    • :) and all the birds you can eat too :)

      • I know you've got some :)s in your comment but the "birds death" thing is mainly related to one bad placed wind farm in California that is place in a migratory route for some birds, its not as bad as the naysayers make out, cats kill a multitude more birds than virtually all other man made systems
  • Isn't Hammerfest a Scandinavian Folk Metal band. I swear I saw them in 2013 with Amon Amarth and Korpiklaani.

  • Daily tides here reach 11 miles per hour, and can go as high as 18....

    Well, damn! And here I thought going to 11 [youtube.com] was really something.

  • by BoRegardless ( 721219 ) on Monday November 03, 2014 @02:37PM (#48303019)

    You can pick a shallower water area for its higher tidal flow speed, but that increases stresses and chance for damage.

    But there are deep water currents that are consistent at 5-6 knots which avoid almost all marine life in some places down 5-6000 feet deep. A few are in close to shorelines.

  • While I'm certainly all for alternative forms of energy (which I consider anything not driven by fossil fuels.) this seems like a really piss poor idea and I'll tell you why: ITS SEAWATER, one of the most corrosive environments on this earth, and you wanna build things down there and expect it to keep going for a while? No. The maintenance alone is probably going to offset any perceived energy generation. There is no way this set up will generate enough power to pay for its maintenance over 50 years, if

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