Nature reports that a small farm of tidal-powered turbines in the East River will start providing power to New York City come September. Once operational, this will be the first power-producing tidal turbine farm in the world. The blades of the turbines will spin as the river's tides flow in and out, producing about 200 kilowatts total. While this is a relatively small amount of power, it will provide a proof-of-concept for a possible larger installation of tidal turbines later on.
The New York project signals a trend towards cheaper, free-standing turbines that can be dropped into oceans or estuaries. The first experimental tidal mills were installed last year: a 300-kilowatt turbine was sited off the north Devon coast in Britain and another of the same capacity was placed near Hammerfest, Norway. The two European companies behind them are planning to expand these individual mills into turbine fields.
Taylor believes he has an advantage over his competitors, because the design of his turbine blades means that they keep spinning even at slower water speeds.
Expanded to a full 200-300 unit farm, the tidal turbines would produce 6.5-10 megawatts, not nearly enough to power all of New York, but a good addition to a renewable mix. The unit cost is fairly high right now, but designers expect prices to come down as the technology matures.
This is fantastic news. Tidal power can become the Hydro of the '00s given enough research and experimentation. Once the price comes down (particularly maintenance issues) it will be a much more compelling technology than, say, solar currently is.
Any word on how the tidal power experiments in the UK are faring? The article mentions the huge French hydro project in La Rance, but only talks about the UK and Norwegian experiments in passing.
This power isn't free... shouldn't we be worried about using up a non-renewable resource like the kinetic energy of the earth and moon?
I'm surprised you didn't emphasize the key point: "nine metres below the river's surface" - ie. "not disrupting the coastal view" like the "wave driven generators" off the Massachusetts coast that have been delayed indefinitely by the protests of coastal landowners. In other words, it's limited only by *engineering* issues, not social and political ones.
(As for the non-renewable comment: run some order-of-magnitude numbers. Local ecosystem disruption I'd consider - influencing earth-moon orbital mechanics I would not.)
How can there be a tide going both ways in a river I wonder?