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Green Energy From Manhattan's East River
circletimessquare writes "New York City's waterways are geographically unique in that they force tides from Long Island Sound down the East River in one of the most concentrated, powerful flows on the East Coast. If all goes as planned, a company called Verdant Power will build a $20 million, 10 megawatt underwater turbine field there by late 2005. The turbines spin slowly enough so that they pose no threat to wildlife (har har), are placed in spots where they do not interfere with commercial shipping, and are deep enough to not interfere with recreational boating. About the only drawback to the scheme are the supply shortage periods when the tides are slack. The New York Times has the scoop."
10MW won't make a dent I think, but it's a good idea as an experiment. It would be barely 1% of the capacity of one of the nuclear plants up the road.
"The first rule of intelligent tinkering is to save all the pieces." --Aldo Leopold (Paraphrased)
There is only one other project like this that I have heard of. It's in France, and its the Usine de la Rance.
The Usine Maremotice de la Rance is based on the French equivalent of the St Lawrence Bay. This is a place where the tide amplitude is one of the highest in the world.
At low tide, the sea truly is miles away from the shore. I have been there, and it's amazing how far away the ocean can go... and how fast it can come back. Saint Malo, the nearest city, was actually (a few centuries ago) an island at high tide, and people had to wait for the low tides to cross over the sand to the city.
The 'Usine' itself has been pretty successful, and provides 'clean', tide-based electricity to Saint Malo and other cities, but its ecological impact has been underestimated: the Rance, which used to be a clean river is now severely clogged with mud and silt that are not evacuated by the tide, to the detriment of wildlife. Many bird and fish species have left the river for others or have died off completely.
I hope the company that will build the New York project has taken this data into account for its project (which seems to be the case).
The right to offend is far more important than the right not to be offended. (Rowan Atkinson)
Sure can!
Check this article entitled San Francisco-area garbage generates energy.
And now from the SANE point of view ...
... like the East River if you just happen to be in that part of the world.
just so you know, PCB's often build up on road surfaces, having been expelled in small quantities from vehicle exhaust.
That gets washed into the surrounding drainages
In Victoria BC, environmentalists are trying to sue the city for allowing PCB's to enter the surrounding ocean. Victoria doesn't dump PCB's. The source was found to be the runoff from roads.
Victoria isn't even a big city.
George Bush + Linux = "I will not let information get in the way of the fight against Windows"
Groundwave is a very important factor at lower frequencies, because low frequencies 'travel' along the ground (a natural property of their longer wavelength). The more conductive the ground is, the farther the signals will travel (based on the output wattage of course).
For very high frequencies, like Wi-Fi, the groundwave is considerably less important. With Wi-Fi, the line-of-sight is the most important factor. So you're right if you're thinking about higher frequencies, which are where most of the modern radio systems are operating. My book is about mediumwave (AM band) broadcasting however, so concepts like groundwave still play a pretty important part.