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Monday, April 23, 2007 Tidal Turbines Help Light Up ManhattanTurbines are being submerged in the East River to generate electricity from rapid tidal currents. By Peter Fairley
Working from barges and tugboats off New York City's Roosevelt Island, engineers are battling northeasters and this month's heavy spring tides to install the first major tidal-power project in the United States. The project involves a set of six submerged turbines that are designed to capture energy from the East River's tidal currents. The three-bladed turbines, which are five meters in diameter and resemble wind turbines, are made by Verdant Power of Arlington, VA. Thanks to lessons learned by wind turbine designers, tidal power is already economically competitive, producing electricity at prices similar to wind power, according to feasibility studies by the Electric Power Research Institute, an industry R&D consortium. And it offers a big advantage over wind and other renewables: a precisely predictable source of energy. As a result, developers in the United States have laid claim to the best sites up and down the Atlantic and Pacific coasts. In the past four years the Federal Energy Regulatory Commission in Washington, DC, has issued preliminary permits for tidal installations at 25 sites, and it is considering another 31 applications. Current-harvesting turbines represent a sharp break from the first wave of tidal power, so-called "barrages" in which impoundments installed across estuaries or bays created hydroelectric reservoirs refilled twice daily by rising tides. The La Rance barrage in Normandy has produced up to 240 megawatts of power--as much as many natural-gas-fired power plants--since 1966. Halifax utility Nova Scotia Power has been generating up to 20 megawatts of power since 1984 at a tidal barrage in the Bay of Fundy, whose funnel-shaped inlet produces the world's largest tides--16 meters at its head. But these constructions have fallen out of favor because of their outsize impact on ocean ecosystems. James Taylor, general manager of environmental planning and monitoring for Nova Scotia Power, notes that commercial-scale installations planned for the Bay of Fundy in the 1980s would have altered tides as far away as Boston. "It would be a pretty hard thing to get permitted today," says Taylor. Hence the attraction of in-flow turbines such as Verdant's. "The whole point of doing kinetic hydro is to have a very small environmental footprint," says Dean Corren, Verdant's director of technology development, who designed the tidal turbines in the early 1980s while conducting energy research at New York University. Corren's team installed its first two turbines in the East River in December. One has been delivering a maximum of 35 kilowatts of power to New York City, swiveling to generate power as the river swells with the high tides and empties with the low. The other turbine delivers performance data that Corren says will be crucial to refining the blades and gearbox, generator, and control system to optimize power generation. This month Verdant added four more 35-kilowatt turbines. Corren says Verdant is now working on a next-generation design that will be cheaper to mass-produce, in anticipation of installing a farm of at least 100 turbines at the East River site. |
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Comments
theBike45 on 04/23/2007 at 8:54 AM
13
very few U.S. locations allow for significant tidal energy extraction, and the amounts extracted aren't that great. As I recall, New York has the best situation and yet will only yield around 10 megawatts of power. I'd guess that city needs something like 20,000 plus megawatts during peak demand. More than a drop in
the bucket, but also more than 30 $2 million plus wind turbines can produce and more than 200 wind turbines can produce during peak demand periods.
kitk on 04/23/2007 at 2:46 PM
50
Tysto on 04/23/2007 at 8:55 PM
16
dmm on 04/23/2007 at 3:09 PM
135
Reduce, reuse, recycle. Give a hoot, don't pollute. Save the rainforest. Don't let species go extinct. Ranger Rick and friends were giving us good sensible advice LONG before the supposed global warming crisis. My advice is: Forget about greenhouse gasses. Simply consume less and spend less money. By doing so, you will naturally reduce your environmental footprint.
My policy recommendations (for the U.S.):
1. Permanently raise taxes on energy while raising personal exemptions on income tax to remain revenue-neutral and not unduly burden the poor. The free market will then act to reduce national energy use.
2. Spend more money on urban infrastructure to encourage people and businesses to stay close together. Save the countryside for farmers and wildlife.
3. Encourage people to save rather than consume. Do not tax interest income below a generous amount. Do not take savings into account when doling out college financial aid, Medicaid, etc. Why should wastrels who mess up the environment get MORE gov't help while eco-friendly savers get LESS?
4. Commit to a steady long-term program of research on energy saving and clean(er) energy science and technology. Attempting quick fixes and Manhattan projects will almost always backfire. [Manhattan projects! Get it?]
nekote on 04/24/2007 at 9:57 AM
109
Efficiency versus Conservation.
Conservation has a connotation of going / doing / using less "stuff" - of saving / not spending.
Efficiency has a connotation of going / doing the same, while using fewer / less resources.
Both are usually about less resource consumption.
A whole lot more people embrace being efficient with their usage of water, energy, carbon, ... ?
Versus shunning conservation.
Please consider using the word efficiency, rather than conservation.
sbkadar on 04/23/2007 at 10:32 PM
4
tn on 04/24/2007 at 9:43 AM
1
Resources are not, they become.
architectrb on 04/25/2007 at 2:55 PM
2
It does not depend on wind or sun; no fish problem; never stops because it is powered by the moon and sun; offer $10MM prize for most efficient generator - maybe compressed air?
zig158 on 04/26/2007 at 4:04 AM
42
Rubingrinnola on 04/30/2007 at 9:45 AM
2
Since river currents are also relatively stable and fast moving, it seems to me that they could work there as well.
skiyryder on 05/01/2007 at 10:12 AM
1