German power giant E.On is expected to announce on Thursday that the world's largest wind farm, close to Sweetwater, Texas, is open for business and generating juice.

The wind farm in Roscoe, just west of Sweetwater, boasts 627 wind turbines, with a total capacity of 781.5 megawatts.

That's huge – about as much capacity as a coal-fired power plant, and enough juice to power 265,000 homes. The farm covers nearly 100,000 acres – an area several times the size of Manhattan.

As some wind farm developers slow down in Texas, E.On keeps building. T. Boone Pickens had planned to build an even larger wind farm in the Panhandle but decided instead to disperse the turbines around the country.

"We think Texas historically has represented a good market," said Steve Trenholm, E.On's chief executive for climate and renewables in North Texas. "And it is and has been quite friendly" to wind development.

The Roscoe wind farm, which employs about 70 people, might not be the last facility E.On builds in Texas. Trenholm said he would like to build more turbines in Texas and other areas of the country.

The problem with building new wind farms in West Texas now is that wholesale power prices are depressed because the recession has reduced demand for electricity. An influx of new wind power supply also has caused prices in West Texas to drop.

Trenholm said he hopes new transmission lines can solve the problem by taking more of the West Texas wind power to North Texas and Houston. Texas is in the process of erecting $5 billion in new transmission lines to bring electricity generated by wind power in West Texas to urban areas.

Still, he said, his wind farms are profitable right now. "They're not where we would like them to be, but they're doing OK under this environment," he said.

On a global basis, E.On reported earnings of $73.6 million for the first half of this year from its climate and renewables unit.