Wind + water = untapped energy: An abundance of power exists above Earth's oceans, study finds

Jun 30, 2009 by Jennifer Fitzenberger
A study by UCI Earth scientists finds that wind energy over the planet's oceans is a vastly underutilized renewable resource.

(PhysOrg.com) -- Wind energy over the planet's oceans is a vastly underutilized renewable resource, according to UC Irvine researchers.

At 80 meters above the ocean - the typical wind turbine height - more than 50 percent more power is available than at 10 meters, the height important to the shipping industry upon which previous wind estimates were made.

Though Europe has led the development of offshore wind farms, conditions make U.S. coastal oceans prime for strong winds: The air is stable, and the water is cold, notes Charlie Zender, study co-author and Earth system science associate professor.

"In the midlatitudes, you find these stable environments where air really takes off and accelerates rapidly as you move away from the ocean's surface," he says. "There's a lot of power in the wind. The more we compare it to other energy sources, the more I'm impressed."

Ocean has a lot of perks: It is clean and renewable and takes no land-based real estate - unlike other energy sources, such as coal-powered plants. Ocean turbines, typically placed in water up to 40 meters deep, can be closer to population centers than power plants, reducing leakage and cost of transmission lines. And networks of ocean wind farms are as reliable as coal plants at producing consistent levels of power, Zender says.

Offshore wind turbine towers, however, must be anchored to the - restricting their distance from the coast - and they cost about 50 percent more than land models, partly because upkeep is more difficult. "There are issues with every energy resource," Zender says, "but wind has relatively few compared to coal, ethanol or nuclear power."

The study by Zender and graduate student Scott Capps is the first to calculate potential wind energy over the ocean at realistic turbine heights. Researchers started with the previous 10-meter wind estimates and made adjustments for humidity levels and air and ocean temperatures, which influence wind speed.

With global calculations made twice a day between 2000 and 2006, they estimated the average global ocean wind power at 841 watts for every square meter swept by turbine rotors. A single turbine produces about 1 million watts of power, enough to continuously supply about 1,000 houses.

Says Zender: "When you put our research together with existing studies over land, you get - for the first time - a global estimate of wind power reserves."

The National Science Foundation and NASA supported the study, published recently in the journal Geophysical Research Letters.

Provided by University of California, Irvine

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Spdrfall
not rated yet Jun 30, 2009
Just a thought.. Have we looked into electric powered ships boasting wind farms above deck? Is that even feasable?
nkalanaga
5 / 5 (2) Jun 30, 2009
The one problem would be that they would have one of the disadvantages of a sailing ship, but reversed. It would be hard to sail downwind, unless it was a very strong wind, because at some point the ship's speed would equal the wind's, and the net air speed would be zero. Thus, no power! Also, generating energy by using the wind produces drag, and I doubt that the energy produced could exceed the drag on the turbines. If that's the case, you also couldn't sail INTO the wind, because the wind would blow you backwards as fast as your engines are driving you forwards.

Sails actually act as airfoils, and the wind blowing across them generates horizontal "lift", wich drives the ship. Here that force would be used to turn generators, which would be a source of extra losses. If you want a wind powered ship, it's more efficient to use sails.

Which may not be a bad idea, in some cases. If speed isn't a factor, why not go back to sails? Keep the engines as backup.
PPihkala
not rated yet Jun 30, 2009
I think there already exist tech that is better than sailship. It's kite assisted powered ship. It's better than sails because there's more wind power the higher your airfoil is located. As with sails, if the wind is against traveling direction, just take it down and move only with engines.

Also kite power over land might be competing with ocean wind turbines. Of course it has it's own benefits and problems. Just look for relevant articles that have been here earlier.
PinkElephant
5 / 5 (2) Jun 30, 2009
Says Zender: "When you put our research together with existing studies over land, you get - for the first time - a global estimate of wind power reserves."


Which is WHAT, exactly? I hate it when reporters leave me hanging like that...
Avitar
not rated yet Jul 01, 2009
Sure it exists but will we be allowed to tap it. Just to south east of Connecticut is one of the prime whind spots in the United States. To put wind generators out there will require both Kennedy and Kerry to drop dead. that is easy for one but both of them dropping dead just isn't in the cards.
RAL
3.7 / 5 (3) Jul 01, 2009
Great! I'm all for it. Now explain again why if it is so terrific we need to spend tax money hand over fist year after year to make this stuff happen.
GaryB
not rated yet Jul 01, 2009
Just a thought.. Have we looked into electric powered ships boasting wind farms above deck? Is that even feasable?


Depending on what you mean exacty, you are propsing a perpetual motion machine. Sailing down or across the wind, you might be able to turn some of the wind into electricity to drive a propeller. Sailing up wind will cause you to run afoul of the the law of entropy so that you could not produce enough energy to push against the wind from which you derive your energy.

But wait, I have a simpler scheme: Just put up a big sail and you can directly convert wind to propulsion without the losses of converting to electricity first. Pure mechanical conversion known to the ancients as: a sailboat. You still can't sail directly up wind though for the above reason.

Now, if you made the sails out of some flexible solar panels, you could indeed turn that propeller.
goldengod
1 / 5 (1) Jul 01, 2009
He's suggesting that the wind farm can be located on deck of a ship instead of anchored to the ground. Then the ship can be anchored or left to float and occasionally right itself by tapping some of the energy from the wind to power a propeller and reposition itself.

If the boat was moving against the wind or with it would have relatively little effect on the propellers. Tidal movement would cause more resistance. However if there were 1000 wind turbines and only a couple of propellers that would provide a large amount of energy for running the propellers which would only be needed for occasional realignment due to the anchors taking most of the strain.

They would probably need some new tech for the flexible and adjustable high voltage cable system to pipe the captured energy back onshore.
Quantum_Conundrum
3 / 5 (2) Jul 01, 2009
There is a significant problem with ocean based wind power in the U.S. for the gulf coast and even east coast, i.e. HURRICANES.

The wind from category 3-5 hurricanes often breaks anomometers, so what do you think it will do to a giant wind turbine designed to capture the maximum amount of wind? Oh yeah, it will demolish them by the hundreds...just one hurricane hitting an ocean based wind farm will totally destroy the entire project from either the wind itself, or the wave action on top of the storm surge.

Hurricanes are so common that it really isn't even a "hit or miss" thing. A category 3 or 4 storm passes relatively near each major coastal zone almost every year. Even if the wind farms could survive the wind events, the wave action will demolish them, even from distances of hundreds of miles See Ike, Katrina(at one time, approximately 17.9 meter dominant wave heights in the gulf with at least one rogue wave of 79ft,) Ivan (at least one wave was reported by an oil platform as high as 90ft,) Rita, Camille, Hugo, Isabel.

Whle those are extreme storms which won't happen all the time, still, you can be reasonably sure that any wind farm in the gulf or east coast will be struck by AT LEAST the outter bands of a minimum hurricane every 1 to 3 years, and will take a direct hit from a major hurricane every few years. A point offshore in the water has a greater percentage chance of being hit by a storm of a particular strength than a point on land, because its easier for a strong storm to still be...strong...by the time it reaches taht point, since it is still over water.

Along the east coast, the way they hook just before hitting land every time, a single hurricane could wipe out hundreds of miles worth of turbines, and this WILL happen every few years, because they follow the same pattern every year or two.


In europe, they get storms, but they are mostly upper level features, not catasrophic surface wind events like a hurricane every few years. This just won't work on the east coast or gulf. Maybe west coast, but not east or gulf.
PinkElephant
not rated yet Jul 01, 2009
@Quantum_Conundrum,

Dude... Don't you think the designers would design accordingly, if they wanted to deploy in those locations?? Have you counted the oil rigs in the Gulf of Mexico? What makes the complex, bulky oil rigs better capable of withstanding hurricanes, than the much simpler, monolithic steel-rod construction of a wind turbine tower?

If the engineers designing these things have a single solitary functioning neuron inside their crania, they will allow for the turbine blades to fold and latch to the tower's stem, if not completely stow away inside it -- or something equivalent -- when a major hurricane approaches. Just like a sailing ship pulling down the sails to weather a storm...
GrayMouser
not rated yet Jul 02, 2009
Sure it exists but will we be allowed to tap it. Just to south east of Connecticut is one of the prime wind spots in the United States. To put wind generators out there will require both Kennedy and Kerry to drop dead. that is easy for one but both of them dropping dead just isn't in the cards.

And off the coast of Florida and California where they don't want ugly structures spoiling their views...
Crossrip
not rated yet Jul 06, 2009
There are currently thousands of boats with wind turbines providing power for the vessel. The turbine acts as a battery charger and works well for 12 or 24 volt systems.
http://www.superwind.com/
Velanarris
not rated yet Jul 06, 2009
Sure it exists but will we be allowed to tap it. Just to south east of Connecticut is one of the prime whind spots in the United States. To put wind generators out there will require both Kennedy and Kerry to drop dead. that is easy for one but both of them dropping dead just isn't in the cards.


That'd be a great place, if you want to completely eliminate the New England fishing industry. A lot of that area is off limits to projects of any kind as those banks are quickly becomming threatened areas.
GrayMouser
not rated yet Jul 19, 2009
Well, if you look at Austin Texas for an example of how well wind power works your likely to say 'the he!! with it!'
http://www.states...ice.html