Future aviators will need to scan the skies for more than just other aircraft. Several companies are perfecting designs for airborne wind turbines that will hang in the sky at the end of a tether, possibly as high as 30,000 feet AGL.

Joby Energy says its design for a multi-wing 2 MW airborne wind turbine (shown above) operating at an altitude of 2,000 feet, would produce the energy equivalent of two 2 MW conventional mast-mounted wind turbines, and require approximately one-twentieth the materials.

But Joby has it sights on higher ground—much higher. By boosting its airborne wind turbine to the flight levels—where jet aircraft are happiest and wind speeds are usually twenty times greater than at 2,000 feet—Joby says it could easily and efficiently tap into the more than 870 terrawatts of energy scientists estimate is produced each year by global winds. Current total global demand is just 17 terrawatts.

Magenn Air Rotor System

The Magenn Air Rotor System (MARS) from Magenn Power, Inc.

Another company, Magenn Power, Inc., is currently testing a balloon like airborne wind turbine. Dubbed the MARS (Magenn Air Rotor System), the device is filled with helium and operates at altitudes up to 1,000 feet AGL.

Anticipating the proliferation of these new technologies, the FAA today announced new rules for testing experimental airborne wind-energy systems. Previously treated as moored balloons, the new airborne systems must now comply with rules governing structures exceeding 200 feet AGL.

Each deployment must be approved by the FAA on a case-by-case basis, after thorough evaluation of the system’s characteristics and potential impact on navigable airspace, and may not exceed 499 feet AGL. The new rules apply to experimental systems only. Proposals for permanent, fully operational systems will be addressed in the future, the FAA said.