Slashdot Mirror
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...
This is a sig. It is appended to the end of comments I post.
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.
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?
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
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?"
But what will they do when they've used up all the ocean's energy and the water doesn't move anymore?!?
This guy's the limit!
Has there been any study on the impact this causes to the ocean currents?
AAAAARRRGGH!
The turbines are about 150' across. The gulf stream is BIG. Do the math.
-jcr
The only title of honor that a tyrant can grant is "Enemy of the State."
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
The impact of one (or even a lot) of generators is much less than the impact of changing salinity in North Atlantic seawater due to the arctic and Greenland ice melting. THAT will eventually reach a tipping point and break the Gulf Stream circulation.
More like Grinding Nemo...
...carrier dead.....
I would think that all the sunken ships/airplanes out there would cause more damage to the stream than a passive turbine.
Sid Meier was very forward looking. Tidal generators anyone?
Ok, maybe not the same as tidal generators but pretty close and, presumably, a bit more consistent.
We will bankrupt ourselves in the vain search for absolute security. -- Dwight D. Eisenhower
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.
It is so highly unlikely that one turbine would have any significant effect on the ocean currents as to cause any noticeable environmental change. But then Bermuda will eventually need more power, and so will Cuba, Florida, Tennesse, New York, Ireland, France, Spain, Morocco, Mauritania, Brazil, Venezuela and Maybe back to Puerto Rico... eventually this could work out to a whole lot of turbines with the ability to sap a significant amount of energy out of the gulf stream. A single automobile causes virtually no incremental environmental damage., but an entire traffic jam's worth of automobiles does.
I'll never make that mistake again, reading the experts' opinions. - Feynman
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.
Nothing to see here. Move along.
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.
...The gulf stream [wikipedia.org] is BIG. Do the math.
.75 just for the sake of argument:
1e+7/0.75/1.4e+16 = 0.000000095% of the current's power per generator.
OK. I did the math. According to that wikipedia article the Gulf Stream is sinking about 1.4e+16 watts. The proposed turbine will generate 1e+7 watts. I didn't see any efficiency figures so let's give them credit for
There you go.
You never really know how close to the edge you can go until you fall off.
As a matter of fact, yachts these days fairly often have immersed generators. As the yacht gets hauled along by wind power, the generator trails and spins in the water.
They generate quite impressive amounts of electricity at the cost of a knot or two in speed.
Mind you, the water speed of those trailing generators is considerably higher, quite often, than the gulf stream, but it's quite enough for some impressive juice.
"The 150ft long deep sea generator with a four-blade turbine inside would cut Belco's dependency on oil"
And I didn't even RTFA. I just RTF blurb. Jesus, how lazy can you get?
My blog. Good stuff (when I remember to update it). Read it.
Even if you had the technology to stop ocean currents, doing so would obviously also stop your ability to get energy (because there would be no current). The most energy you can get from a turbine is known as the Betz Limit., which is approximately 59.6% for a wind turbine. I don't know if it's the same for a water turbine, but there is a limit.
My Freakin Blog
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!
Jesus? Christ, that pun went straight over your head didn't it? ;-)
Title of Slashdot post: "Underwater Ocean Currents USED to Power Bermuda". Got the joke yet? OK, sleep on it then...
I don't know much about ocean currents and how they work, but my electricity driven mind makes me think that putting a bunch of turbines in the middle of the ocean current will cause the current to adjust its path to go around them. Right?
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.
I don't know if Tennessee will have much much impact on ocean currents, since it's the only place on your list not on the ocean! However, Nashville is one of the most popular entertainment centers in the world, and it is often called the Third Coast (with New York and Hollywood on the other two coasts).
:-)
The Tennessee Valley Authority has three nuclear plants which produce about 30% of the power TVA generates. Tennessee has some of the cheapest electricity rates in the nation.
In addition, we have Oak Ridge, which produced the uranium used for the world's first atomic bomb in the Manhattan Project. They even have a festival now celebrating their secret past.
But we don't have any oceans. Sorry!
Though that is a common mistake.
There is the Seaflow project in the Bristol channel (that's England / Europe), which does pretty much the same thing. There is at least one more of these underwater ocean current devices that I don't remember, and I've recently visited the Enermar system in the Strait of Messina. See this Uni Strathclyde site on more details.
A good Google search term is Ocean current energy, or Marine current energy.
Enough Karma Whoring for this time! It's a pity they won't go with offshore wind energy - the resource at the proposed offshore site was quite good, so the cost would have been quite tolerable, especially against shipped in 70$/brl oil. However, it's going to be interesting to see whether they can make this work. It's interesting that Current to Current can offer a price per kWh without having prospected the currents in detail... and hopefully, the device is very reliable, because getting divers into 75-200 m depth is hardly simple (means, it takes time to fix things).
Hurricane Application Group, Dept of Meteorology Control, Ministry of Proactive Defense