[The Vector] Low Cost Power from High Altitude Winds
![[The Vector] Low Cost Power from High Altitude Winds](https://www.2greenenergy.com/wp-content/uploads/2010/12/kitegen.jpg)
A near full-scale prototype of an airborne wind energy system that generates power from constant, high-speed, high-altitude winds will be tested in Piedmont, Italy, in the coming weeks.
When fully operational, KiteGen should be capable of generating 3MW of power. The KiteGen concept was recognized at the Copenhagen Climate summit as among the top 20 leading innovations.
The prototype 150m2 kite will be automatically operated from a revolving dome at ground level – similar to a ship’s gun turret – that contains the electronic control systems and the mechanism to feed the kite in and out. As the kite climbs its fast-turning cable spool generates electricity. When the kite reaches its maximum height, tension on one side is released and the kite begins to drop groundwards. The falling cable is rapidly rewound, needing only a fraction of the energy that was generated as the kite climbed. Once the kite reaches its minimum height, tension is restored to both sides of the kite and it starts to climb once more. When the system has been fully tested, it is intended to use a 500m2 kite.
A reduced scale version of the KiteGen was successfully tested two years ago. The 20m2 kite on a 1,000 meter cable produced 40 kW of power and its behaviour confirmed the computer simulations.
The advantage of KiteGen is that it can exploit far more constant high-speed winds than are available to traditional wind turbines. While the KiteGen tests will be restricted to a ceiling of 300 meters, there are exploitable winds available from an altitude of just 200 meters. And KiteGen does not need the massive infrastructure required by traditional wind turbines. To keep costs to a mimimum the dome is constructed aluminium, steel and carbon fiber, according to a report in The Oil Drum: Europe. Dyneema (high strength polyethylene) is used for the cables that control the kite. The power generator is based on neodymium-boron-iron magnets.
According to Mario Milanese from Turin Polytechnic, kite generators have the potential to generate at a cost of less than €50 per MW hour – less than the cost of fossil fuels. A farm of kites could achieve a power density of 20MW per square kilometer – which is comparable with a nuclear power plant. And the high altitude winds can be reached from virtually anywhere on earth.
Kite Steering Unit
The key technology on KiteGen is its KSU or Kite Steering Unit. The kite has onboard sensors that report its position and speed. At ground level further sensors monitor wind speed, wind direction and line tension. That data is fed into the control software that in turn controls the electric drives and winches in the actuation unit. The kite is piloted to fly a series of figure 8 patterns, maximising the energy generated before the tension has to be released for recovery.
The KiteGen project was delayed for more than a year when residents from Berzano, the original proposed testing site near Turin, launched a campaign of opposition. Eventually, Massimo Ippolito, President of KiteGen Research decided to move to the new site in Piedmont, though that meant beginning permitting applications all over again.
In the US, Google is one of the sponsors for a tethered wing system that generates power from onboard turbines, being developed by Makini Power. Their M1 prototype with a wingspan of 35 meters is intended to generate a MW while circling at altitudes of 200 to 400 meters.
