Business Report

Electricity from the Air

California company Makani Power is developing a flying wind turbine designed to generate cheap renewable power.

by Ted Greenwald
December 26, 2011

Flying windmill: Multiple exposures show the flight pattern of the Makani Airborne Wind Turbine, built by Makani Power. The electricity-generating glider is attached to the ground by a carbon-fiber tether. The craft flies “crosswind,” or perpendicular to the direction of the wind, as a kite does. In early tests, prototypes have generated five kilowatts of electric power. Larger versions with 88-foot wingspans able to generate 600 kilowatts of power are planned.

Hovercraft: The Makani Airborne Wind Turbine sits on a runway at the decommissioned Alameda Naval Air Station outside Oakland, California. The prototype carbon-fiber craft weighs 120 pounds and has a 26-foot wingspan. Under battery power, rotors on the wing allow the vehicle to hover. During flight, they act as small electricity-producing wind turbines. Development of the flying turbine has been funded with a $3 million grant from the U.S. Department of Energy.

All-nighter: Control-team members Kenny Jensen, Erik Chubb, and chief engineer Damon Vander Lind await stronger winds during a July 2011 test of Makani’s flying wind turbine on Sherman Island, a remote spot in Sacramento County, California. During tests, the team passed a milestone by generating power continuously for five minutes of computer-controlled flight.

Double duty: Makani pilot and mechanical engineer Scott Parker poses with carbon-fiber propeller blades at Makani’s workshop at the decommissioned military base. The rotors of the craft can collect wind energy or provide lift for the flying turbine.

Distant aim: During the tests on Sherman Island, a flying turbine is attached by a carbon-fiber tether to a converted fire truck (lower left), which is being used both as ballast and to collect electrical energy generated by the craft. Wind blows more steadily at higher altitudes, which are beyond the reach of conventional wind turbines—but not tethered ones.