BOULDER - A former National Renewable Energy Laboratory chief engineer has started a new company in Boulder to design and build the next generation of wind turbines.

Boulder Wind Power, headed by Sandy Butterfield, plans to employ 15 people by this summer, and possibly 30 people by the end of the year, at its new headquarters at 2845 Wilderness Place. It is looking to attract wind, electrical, structural and mechanical engineers and analysts.

Butterfield, the company's chief executive officer, will bring his expertise from NREL, where he worked for 24 years, including the past 10 years as the chief engineer for the federal laboratory's wind program. From 1980 to 1985, Butterfield was a co-owner of ESI, a company he later sold that developed and sold small wind turbines.

New Enterprise Associates, a California-based venture capital firm that recently helped fund Boulder-based Clovis Oncology Inc., is providing Boulder Wind Power with a "substantial" but undisclosed amount of financing, Butterfield said.

Boulder Wind Power will focus on designing, developing and eventually manufacturing large megawatt wind turbines, primarily for onshore and perhaps offshore use. The turbines will feature redesigned "direct-drive generators" - the key innovation and challenge for the company, Butterfield said.

"Normally, the rotors in a wind turbine turn slower than the generators, which like to move fast," Butterfield explained. Frequently, engineers will design a gearbox to speed up the rotors to match the generators - it's the least expensive solution today but not the most mechanically reliable.

Direct-drive generators are more reliable - everything is moving at the same speed, Butterfield said. But direct-drive generators make the wind turbine heavy and expensive.

"Our challenge will be to make reliable direct-drive, megawatt wind turbines as light and inexpensive as gear-driven systems," Butterfield said.

Butterfield hopes to have a proof of concept within two years, and a prototype machine in three years. The large 1.5-megawatt wind turbines would span about 88 to 105 meters in diameter.

"A lot of people ask: 'Are you going to build those in Boulder?' " he said. "We'll probably find a larger location outside the city or in Denver when it comes to that point, but the design team will be here in Boulder."

Butterfield said he chose Boulder because,  "It's an easy place to attract competent wind-energy engineers." He's already convinced new employees from Montana, and as far as Denmark, to move here.

Jim Smith, vice president of engineering and a principal of Boulder Wind Power, is moving from Connecticut, after working 30 years for General Dynamics' Electric Boat division, developing propulsion systems for submarines.

There's also local talent and expertise backing the company. Ron Bernal, who previously worked with Boulder-based Sequel Ventures Partners and is now with New Enterprise Associates helping fund Boulder Wind Energy, sits on the company's board.  Bernal helped start the Colorado Cleantech Industry Association in Denver and was previously an executive at Cisco Systems and Silicon Graphics.

Attorney Jim Linfield, a partner with Cooley Godward Kronish's Broomfield office, also helped with the startup of the company. 

Ted Harris with Studley Inc. and Jason Kruse with The Colorado Group Inc. helped broker the real estate deal for Boulder Wind Energy's new space.

"Boulder has become a center for wind-energy excellence," Butterfield said.  "Quite a bit of that comes from the governor casting Colorado as a wind-energy state."

But don't expect to see big wind farms cropping up in Boulder, Butterfield said.  The area is better known as the place to attract the brains behind wind power.

"We in Boulder think we get high winds, and we do, but we don't get high annual average wind speeds that are good for a wind farm," he said. "We get good bursts of high winds, which is good for testing - like NREL does between here and Golden. The northeast part of the Colorado is better suited for wind farms."