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."
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."
Oh no! (Score:2)
These turbines will kill all the fishies!
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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)
The real danger is these generators will extract all the energy from the tides and the Moon will crash into the Earth.
Re:Oh no! (Score:5, Informative)
That would be a neat trick [cornell.edu]...
Re:Oh no! (Score:5, Funny)
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Extracting Earth-Moon tidal energy actually slows the rotation of the Earth more quickly, transferring energy to the Moon, accelerating it. So the more of these we add, the more quickly we can fling the Moon away from us and have longer days to enjoy.
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Space: 1999 becomes reality?
Please don't say that! It'll give some producer an idea for an ecologically-slanted remake.
Re:Oh no! (Score:5, Funny)
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)
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.
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Re:Oh no! (Score:5, Funny)
Could you please inform the engineers that the North Sea is full of salt water? Armed with that piece of information that I'm sure they don't have, they can take that into consideration when designing this.
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I imagine they have ideas to answer the challenge. Of course the real answer wont come back for years when we get to see whether it succeeds or fails. I like that they try though, maybe one day they'll get it right.
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I imagine they have ideas to answer the challenge. Of course the real answer wont come back for years when we get to see whether it succeeds or fails. I like that they try though, maybe one day they'll get it right.
One day? Powered ocean-going ships solved the problem of operating steel machinery in saltwater a long time ago, with a combination of paint and galvanic anodes.
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Could you please inform the engineers that the North Sea is full of salt water? Armed with that piece of information that I'm sure they don't have, they can take that into consideration when designing this.
More likely they'll have to cancel the project. After all, if it was possible for modern technology to create machinery that works when submersed in salt water, I sure that somebody would have already done it.
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I feel that my submersible wooden barrel boat will turn the tide in the next war!
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The problem isn't the engineering per se. It's getting the costs of the necessary engineering down to a level that makes this economically viable. They probably won't succeed (most similar installations have yet to) but they probably will learn something. And perhaps they will manage it - it certainly doesn't involve any higher grade technology than your average deep sea drilling rig or LNG floating production system.
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What are they going to do, bring lots of pepper to match? Each worker will carry the government issue pepper grinder...
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Probably these guys didn't get into this industry just to waste money. I would imagine that most of the people actually working on this are 1) motivated by the potential profits of mastering and proliferating this technology and/or 2) have a genuine desire to develop more sustainable energy sources and/or 3) masochistic engineers that love a good challenge. All three classes of people would be disappointed with failure, and really jazzed with success. I think that they care about succe
Re:Oh no! (Score:5, Funny)
Oh yes they did! Anyone who tries to design an energy technology not based on coal or oil is clearly an evil motherfucker out to steal taxpayers' money! We should just fucking kill all the scientists and engineers who aren't working on coal, oil, and maybe nuclear, because after all, those are the only options that should ever be fucking considered. Kill scientists. Kill all of them!
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Right, it would be much more sensible to rely on the dwindling money that Scotland gets from north sea Oil, and not encourage new economies to grow.
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The issue cited appears to be "A looks like B, B is considered good, thus package A as B". It's the same thing as progressive education in America: we discovered that faculty education was a broken theory (your brain isn't a muscle, and doesn't get stronger when you flex it), so we threw out everything in education that's actually "education", and replaced it with "experiences". Now American education is a huge waste of time and taxpayer money, but without the trauma of hard work or learning anything.
Po
Two Words (Score:2)
Sacrificial Anodes
Underwater will face the same challenges as Tidal (Score:5, Interesting)
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.
Re:Underwater will face the same challenges as Tid (Score:5, Insightful)
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.
How about: Clean them off.
Re:Underwater will face the same challenges as Tid (Score:5, Insightful)
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.
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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
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Hundreds of barnacle-scrapping robots per unit.
Sounds like a business opportunity to me.
Awww crap, somebody else [dvice.com] beat me to it.
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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.
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Re:Underwater will face the same challenges as Tid (Score:5, Interesting)
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.
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http://en.wikipedia.org/wiki/G... [wikipedia.org]
Oh, yeah...
Re:Underwater will face the same challenges as Tid (Score:5, Informative)
Uh, about that, the Rance tidal plant in France has operated for 40 years with nothing but sacrificial anode protection and it looks pretty good [british-hydro.org] to me (see page 22).
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Neat.
540,000,000 kWh/year is an interesting way to express power though. Especially when it means that a power plant with 240 MW installed capacity is producing 62 MW average power.
This makes sense if 240 MW is the peak power generation, and 62 MW is average, given the cyclic nature of power generation, but still...
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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.
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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
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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
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Simple: coat everything in paint with Transuranic waste additives!
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The ocean is teaming with life....
GO TEAM LIFE!
Sorry, couldn't resist...
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I don't see the problem here. Just put a straw downstream from the turbines and you have instant cioppino.
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that's very easy. dump chemicals around the the whole thing as needed
He he, I know you're kidding... but that would be remarkably stupid thing to do in a high current area :)
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Just do it when the tide changes. No current at slack tide.
I'm skpetical (Score:3)
My grandpa always said that Scotsmen and water just don't mix. But then again, maybe he just meant TRUE Scotsmen.
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I thought there was at least one?
EROEI? (Score:3, Interesting)
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?
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i'm guessing that dams of any kind are going to generate more power than free standing turbines.
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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.
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It's an R&D project designed to determine those things. It even says so right in the summary.
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This article needs fact checking (Score:4, Informative)
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.
Re:This article needs fact checking (Score:5, Funny)
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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
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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.
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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
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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.
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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
That Scientific American figure doesn't help (Score:4, Insightful)
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.
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Re:um, no (Score:5, Funny)
Dams.
I realize some people like to curse dams, but still....
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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...
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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
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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.
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Nuclear is the least damaging to the environment [...]
As long as nothing goes wrong.
Power of the tides... (Score:5, Interesting)
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]
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...watts of energy?
Why the tiny turbines? (Score:2)
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?
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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!
Re:Why the tiny turbines? (Score:4, Informative)
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.
If seawater is 832x denser, then not correct (Score:5, Informative)
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)
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at least try to be accurate? nah, this is /. (Score:2)
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.
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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)
I like how wind turbines look (Score:2)
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.
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:) and all the birds you can eat too :)
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Hammerfest (Score:2)
Isn't Hammerfest a Scandinavian Folk Metal band. I swear I saw them in 2013 with Amon Amarth and Korpiklaani.
as high as 18 (Score:2)
Well, damn! And here I thought going to 11 [youtube.com] was really something.
Tidal Current versus Deep Water Turbines (Score:3)
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.
Bad Idea (Score:2)
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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because some people would probably rather not have a good idea ruined for a generation by a fiasco caused by shoddy implementation.
build it, but don't overstate, and take into consideration that it's a highly corrosive environment... and stuff in the ocean grows on everything... literally everything...
the fucking whales have barnacles growing on them... come on.
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But not sharks. Be like sharks.