Underwater Windmill Helps Power Arctic Village
Energy derived from the moon now trickles into a village near the Arctic tip of Norway via a novel underwater windmill-like device powered by the rhythmic slosh of the tides.
The so-called tidal turbine is bolted to the floor of the Kvalsund Channel and was connected to the nearby town of Hammerfest's power grid on September 20. It is the first time in the world that electricity directly from a tidal current has been fed into a power grid.
The gravitational tug of the moon produces a swift tidal current there that courses through the channel at about 8 feet (2.5 meters) per second and spins the 33-foot-(10-meter) long blades of the turbine. The blades automatically turn to face the ebb and flow of the tide and rotate at a pace of seven revolutions per minute, which is sufficient to produce 700,000 kilowatt hours of non-polluting energy per year—enough to power about 35 Norwegian homes (70 U.S. homes).
"Basically it's like putting a windmill in the water," said Bjørn Bekken, a project manager for Hammerfest Strøm, the company that built the device.
