General Electric's wind energy division is trying to find a "Goldilocks" turbine design, one that's not too big and not too small.
Like other wind manufacturers, GE is benefiting from booming demand for wind turbines in Europe and in the U.S., even with the possibility of a renewable-energy tax credit lapsing later this year.
Still, the rapid expansion is being throttled by high prices of steel and other commodities, making wind power more expensive.So instead of making bigger and bigger machines, manufacturers are trying to squeeze more energy from conventionally sized wind turbines.
That will be done by using alternative materials, better electronics, and shaping turbine blades to better capture the wind, said Stephane Renou, who manages research and development for General Electric's wind technology platform.
"The optimal point is changing...and going bigger is not the answer," Renou said. "Turbines in the two or three megawatt zone are the most efficient and the best cost per kilowatt."
A 2 megawatt or 3 megawatt wind turbine is still large. The tower on a 2.5 megawatt machine can stand nearly 330 feet high....
...One area that GE's wind labs is not pursuing aggressively is energy storage. A handful of companies and utilities are looking at truck-sized batteries or underground compressed-air storage to incorporate renewable energy more reliably.
But Renou said that storage attached to wind turbines is not likely to happen in the next two years. Instead, beefed-up transmission lines, along with smarter power-grid management, could push wind to make up 10 percent of power generation, up from less than 1 percent now.
"The grid is a fantastic source of energy storage. Wind variability can be handled by the grid and grid management," he said. "It's more about policy and grid development."
