  Ground based, wind energy extraction systems have reached their maximum
capability. The limitations of current designs are: wind instability, high cost
of installations, and small power output of a single unit. The wind energy
industry needs of revolutionary ideas to increase the capabilities of wind
installations. This article suggests a revolutionary innovation which produces
a dramatic increase in power per unit and is independent of prevailing weather
and at a lower cost per unit of energy extracted. The main innovation consists
of large free-flying air rotors positioned at high altitude for power and air
stream stability, and an energy cable transmission system between the air rotor
and a ground based electric generator. The air rotor system flies at high
altitude up to 14 km. A stability and control is provided and systems enable
the changing of altitude.
  This article includes six examples having a high unit power output (up to 100
MW). The proposed examples provide the following main advantages: 1. Large
power production capacity per unit - up to 5,000-10,000 times more than
conventional ground-based rotor designs; 2. The rotor operates at high altitude
of 1-14 km, where the wind flow is strong and steady; 3. Installation cost per
unit energy is low. 4. The installation is environmentally friendly (no
propeller noise). -- * Presented in International Energy Conversion Engineering
Conference at Providence., RI, Aug. 16-19. 2004. AIAA-2004-5705. USA. Keyword:
wind energy, cable energy transmission, utilization of wind energy at high
altitude, air rotor, windmills, Bolonkin.
