CNET has an interesting article on the trend toward bigger wind turbines operating at slower wind speeds:

…some wind-turbine makers are shifting their focus toward building bigger wind turbines that can harvest the lower-speed winds that are more readily available. This next generation of wind turbines is no small matter: their rotors have a diameter the size of a football field.

In general, wind turbines get more powerful and efficient with taller turbine towers and larger areas swept by the blades, according to the American Wind Energy Association. A turbine’s swept area is a key indicator in how much power output potential the turbine has.

“Lower wind-speed turbines certainly open up more land for development,” said Rich Reno, platform leader for General Electric’s new 2.5-megawatt wind turbine. “Larger turbines open up the opportunity to get more megawatts out of a given piece of land.”




Three factors have made it possible to make modern turbines so big, according to General Electric: controlling the load on the grid, new blade design, and new materials to reduce the weight of the turbine.

“As the technology increases in those areas it allows advancement,” said Reno, of GE Energy.

 New materials and construction techniques make it possible to build even larger wind turbines. Siemens says it uses a proprietary manufacturing process, which casts the 53-yard, fiberglass-reinforced epoxy blades in one piece. The process eliminates weaknesses from gluing parts together, as is done with traditional blades and thus makes it possible to make turbines this size.

It is curious that there is no mention of the fact that bigger also means noisier, which is what the so-called NIMBYs are all upset about.