Wind power on the brink of spreading to all US states

New York Times : Friction from trees, buildings, and other structures slows wind that blows over land. When it comes to harvesting wind energy, the taller a turbine is, the better. According to a newly released report from the US Department of Energy, the availability of new turbines that stand up to 150 meters above the ground will extend the practicality of wind energy to the entire US. The new turbines, the report says, will add 0.7 million square miles—equivalent to one-fifth of the country’s surface area—to the 1.1 million square miles where wind power is already practical.