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Underwater Ocean Currents Used to Power Bermuda
Saevio writes to tell us The Royal Gazette is reporting that Bermuda is planning to sink a power generator off the coast to take advantage of ocean currents. The company providing the service, Belco predicts that they will be able to provide approximately 10 percent of the island's energy needs. From the article: "The 150ft long deep sea generator with a four-blade turbine inside would cut Belco's dependency on oil and also benefit the environment by cutting future fuel emissions, he added, stating that the company needed to increase its generating capacity before 2010. Mr. Madeiros, who hailed the technology 'mind-boggling', said: 'This is cutting edge technology, not used anywhere else. One can't help but get excited by this technology.'"
Belco's original press release.
I mean, the energy that otherwise would keep pushing warm gulf stream water towards Europe, that's going to be harnassed by Bermuda...
Does this not risk at slightly lowering the temperature of Europe?
I mean you never know the full consequences... I know, we have global warming to offset that, but still... (and these diverted warmer waters will linger in the southern atlantic, so mean global temperature is still the same...)
"Waste not one watt!" - CZ
Just how many current-surfing turtles and fish can we expect to be missing from Finding Nemo 2 because they get swept into the four turbines?
Power generator mysteriously vanised in the Bermuda sea!
The Tao of math: The numbers you can count are not the real numbers.
I prefer to say "current" technology.
I suppose this begs the question if they are going to be alternating currents or just using a direct one.
"Waste not one watt!" - CZ
What will be the impact of this on the performance of the triangle? I wouldn't want to see halves of ships dissapparing all of a sudden, because there isn't enough power...
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It would be very quick to assume that interrupting current flow would be a definite consideration, but your talking about billions of tonnes of water moving at a very strong flow. There is just TOO much energy involved to worry about whether a turbine will stop ocean currents. Turbines are also passive, allowing water to pass through them. The amount of energy they remove is negligible compared to what is needed to make the water move past it.
I haven't thought of anything clever to put here, but then again most of you haven't either.
From TFA:Asked about the potential impact on Bermuda's unique reefs, she said the efficient generator would have a "very low" environmental impact and said the noise produced by the generator would be "very, very quiet" and would not impact sea creatures. She said the unit would be sunk past the first layer of marine life, and fish below that level would be able to safely swim through it. An electric cable would link the substation to the generator under the sand.
I guess this means that the generator blades spin slowly enough that the fish just swim around the blades? My first thoughts before RTFA were concerns for the reef's health. I would hope that they would design it such that it would not cause a sort of in-the-ocean-current observer effect.
I'd like to see the opining of those with some physics or ocean dynamics experience.
It sounds like a great idea... I wish we had lots more three finkers out there trying to make power in new ways.
A Passionate Independent Musician
I wonder how fast it spins....sushi anyone?
Seriously, I'd like to see their solution for protecting marine life from it. Obviously the fan is cowled, but they don't mention any sort of grating to keep the fish out, I'm sure they did something... Also, does it work off of tidal currents? Or some other deeper current?
Perhaps "Underwater currents TO BE used..." would make a better headline. It's four years before they deploy it. Save the past tense headlines for when I can ask questions like "Does it work?" and "Are there any unintended side effects?" and "Would it scale?"
Yes. Why is it you can never find a Total Perspective Vortex when you really need one?
For crying out loud, why is it every time there's a story about wind power, or ocean thermal power, or any other non-polluting technology, we always get somebody with NO concept of SCALE popping up with this same asinine question?
Because people are dumb. One turbine in the ocean is, literally, a fart in a hurricane.
On the other hand, don't blindly assume humans won't overbuild something. Do you think the first internal combustion engine spurred thoughts of smog-filled valleys hundreds of miles long? No, because it would take tens of millions of combustion engines running non-stop to do such a thing.
This is why the U.S. does so poorly in math and science... people actually think that a 150' turbine could have ANY impact on something as massive as ocean currents. They have no concept of the scale and just how massive the oceans are. .... these are the people that think if we all drive our cars east at the same time, we can alter the earth's rotation and make the day longer.
Hell.. the 8 propellors on a single U.S. Aircraft Carrier probably have a bigger effect on ocean currents than this turbine would... heh...
"I have as much authority as the pope, I just
don't have as many people who believe it" - George Carlin
More like Grinding Nemo...
...carrier dead.....
The use of tidal currents will result in a gravatational drag on the moon. Over a long enough time period, the moon will begin to spiral closer and closer to the earth, finally crashing into the planet.
That way they'd furnish all their power needs.
Knowledge is how to play a game, intelligence is how to win, wisdom is knowing what game to play.
"On the other hand, don't blindly assume humans won't overbuild something. Do you think the first internal combustion engine spurred thoughts of smog-filled valleys hundreds of miles long? No, because it would take tens of millions of combustion engines running non-stop to do such a thing."
Yep that is the key. It really is all a matter of scale. How much will be too much. Right now I wouldn't worry. What we need to do is see if it is practical. If so then we need to figure how much we can extract without causing damage.
As one person said, "The solution to pollution is dilution". A little bit here energy taken from here and moved to their will not really matter much.
It is exactly like the wind power issue. One windmill isn't going to hurt anything. What happens when you start extracting mega watts out of the wind pattern? What about changes to the micro climate just down wind from the wind farm?
I worry more when people dismiss things like that without looking at them at all because it would be too small to matter. Sort of like the idea that foam that you can crumble in your hand could shatter a carbon-carbon leading edge tile. I mean the foam when it hits that hard material will just shatter doing no harm right?
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Keep in mind that the current flows out of the gulf and around the tip of Florida. Right at that point is probably some of the strongest currents. If Florida was smart, they would sink a few of these off the keys. But it will probably take a change in the current Florida admin. before that will be allowed.
I prefer the "u" in honour as it seems to be missing these days.
One turbine in the ocean is, literally, a fart in a hurricane.
I think not! An ocean turbine is literally an mechanical device, while the ocean is literally a body of water.
Turbines are not now - nor have they ever been - farts. And while a hurricane is also mostly water, an ocean is not one.
Literally is not another word for figuratively; it's the opposite.
Literally.
Mod me down and I will become more powerful than you can possibly imagine!
The issue is not hurting fish! Velocity has to be relative to something. From the fish's perspective, the turbine's velocity is relative to the ocean's water. A 150 foot long turbine will spin close to the speed of the ocean water. It will have less velocity vs. ocean water than will a coral reef!
The issue is not stopping the currents! An island in this location would scarcely be noticed, and the turbine will do MUCH less than an island to stop the ocean's flow!
At least it's far enough down to not get destroyed by the first tropical storm. OTOH, anything poking near the surface will get smashed regularly.
The issue is...one turbine generates 10% of the power for an island...and then it gets rusty. He he he....maintenance is a b!tch, then she gets PMS. Imagine loosing 10% of your generation capacity instantly.
Most waves only travel along the surface...I wonder what a good, strong underwater (tsunami-type) wave would do to it?
Andy Out!
What happens when you start extracting mega watts out of the wind pattern? What about changes to the micro climate just down wind from the wind farm?
The latter is irrelevant to all but the people who live there, in the same way the shadow effects of any industrial plant are irrelevant to any but the people who live there. It is not an environmental issue as normally understood--it is a land use or zoning issue. This is not to say it isn't important--it is--but we have centuries of law dealing with things like this, so there are really no signficant unknows with regard to wind farms except for the possibility that they do not have any significant negative downstream effects. That's a pretty good kind of uncertainty to have: "Nothing bad might happen! We just don't know!"
With regard to the question of what happens when we start extracting megawatts from the wind, this is a question that can be answered on the back of an envelope, which I will now proceed to do. Air has a density (rho) of about 1 kg/m**3. Consider wind at 10 kn, which is about 5 m/s. The power per square meter is 0.5*rho*v**3, or about 60 W, of which about half is available to windmills. Wind power has an energy density of about 30 W/m**2, maybe as high at 100 W/m**2 in windy areas. The Canadian province of Ontario has a winter load of about 20 GW and a summer load of about 25 GW. So we're talking about at least 200 million square meters of swept area to accomodate all of it, and maybe over three times this much. This is equivalent to a line of windmills with 100 meter span, 2000 km long removing half the kinetic energy from all the air that passes through them. This is not a small environmental influence. It is hard to imagine that this would not quite fundamentally change energy transport and therefore weather patterns over hundreds of kilometers.
I didn't expect that result when I started writing the paragraph above, but since I'm a scientific rather than a religious environmentalist, I can't simply ignore it. Wind power is still worth pursuing, but it is very clear that it is never going to be more than one element in a mix of alternatives, and is very unlikely to ever generate more than 10% of our power if its environmental impact is to be kept moderate.
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I would like to see that number in context though. How much energy is lost due to fixed objects on the ground? (forests, buildings) It would be interesting to try adjusting the ground resistence in a weather model to see what the effect would be of having a large number of wind turbines. Any atmospheric science students/graduates out there willing to play with their weather models?
Wind power has an energy density of about 30 W/m**2, maybe as high at 100 W/m**2 in windy areas.
Reviewing my own estimate, this number is obviously very sensitive to the average wind velocity, which comes in as the cube. It turns out that average wind speed data for Ontario are available, and my estimate of 5 m/s is on the low side for coastal regions. But even with a more optimistic 8 m/s we are still talking 125 W/m**2 after efficiency considerations, which is only a little higher than my 100 W/m**2 high-end value.
It is also clear that placing wind turbines along the shore will have the lowest environmental impact, because the wind is giving up a lot of energy there in any case.
Blasphemy is a human right. Blasphemophobia kills.
That said, perhaps we can come up with a more environmentally sound solution - how 'bout using the energy stored in the nuclei of very heavy metals (U, PL)? No? Okay, then let's just burn some nice fossil fuels (coal, petroleum). No again? Maybe we should just dam the course of a river and impound a few million gallons of fresh water? No? Still causing environmental change, you say?
Look just by (breathing, farting, pissing . . . living) we have an effect on the environment and the ecosystem. This looks like a decent way of minimizing that impact while preserving the lifestyle which modern technology has afforded us. It isn't perfect? It's a work in progress at this point - get over it!
We have no ideal what this could do. This is not like a windmill which pull energy from surface winds. This is akin to a 10,000 foot high windmill placed directly in the jet stream. This is also not like tidal or wave generators for the same reasons those devices capture energy that would have been expended by waves crashing on shore and slowly eroding beaches. This device will pull energy from currents that effect weather and climate world wide. If it were just to shift the current a few miles on the east coast it could shift the currents hundreds of miles in the north sea dramiticly changing regional climates. Also note that even the biggest aircraft carriers have no effect on these currents as the ships sit less then 10 meters below the water.