Wednesday, December 31, 2008

Weekly Science: Underwater Turbine

Maybe I'm just ill-informed when it comes to science and technology, but it seems like this sort of thing would have been invented and in use decades ago.

"The nation's first commercial hydrokinetic turbine, which harnesses the power from moving water without the construction of a dam, has splashed into the waters of the Mississippi River near Hastings, Minnesota."

I think it's a pretty great idea considering underwater current has nearly 900 times the energy density of wind. And since it's underwater, it isn't as much of an eyesore as a dam is. Plus there doesn't need to be any flooding to create reservoirs. They are big though.

The image above is the actual model being placed in the Mississippi right now. The digital image below is what went into the East River last March.

"The largest test of this new type of power production is under way in New York City's East River, with six 35-kilowatt turbines scheduled to be installed by mid-March in a channel that's off-limits to large vessels. As the 16-ft.-dia. rotors spin, as close as 6 ft. to the water's surface, they'll provide power to a supermarket and a parking garage."
One thing in particular struck me here. These giant turbines with 16ft blades will be whipping around only six feet below the surface. Besides the aesthetics of a natural body of water being ruined, I wonder if this is a danger to humans or destructive to aquatic life.

And how cost effective would this be? Every time one of these things break, do we have to send a team of divers down there to fix it? If they want to put these huge turbines in high volume, high-traffic tidal rivers, what happens when debris slams into these things? Will they break?

It seems the same issues arise when we discuss underwater ocean turbines, except they are even bigger and obviously generate much more power. They are much deeper in the ocean, so humans won't be a risk, but I'm pretty certain marine life will. And how loud are these things? Will oceanographers have to decipher between the songs of the whale versus the hum of the turbines?

There seem to be tons of ideas being tossed around. Again, cost efficiency comes to mind. This one's being talked about for the Gulf Coast.
I'm not sure what the hell is going on here. Are they floating? I think the Gulf has enough rigs out there already, but I guess a few more things to ruin the sunset won't matter. Here's one that is in operation near Ireland.

And finally, here is one that is in the works for Korea. Hyundai is footing the bill.

"The scheme will use power from fast-moving tidal streams to turn a field of 300 60-foot high tidal 1MW turbines sitting on the sea floor. This gives the proposed scheme an operating capacity of 300MW. According to the press release, the power produced from the tidal power plant will generate enough electricity for 200,000 homes and will be completed by the end of 2015."

That's a lot of power. Much more than the ones being used in New York on a parking garage. All of these ideas seem great for coastal cities and towns near major rivers, but what about mountain towns and, you know, most of Africa and Asia? I'm concerned about the environmental damage that is likely to come from this and I hope that environmental groups won't shit on the idea immediately, but at the same time, I want to see a lot of research done to gauge the potential damage to plant and animal life.

It is clean though.