According to Kitegen’s preliminary evaluations, it is expected that wind generators of this type may have much lower electric energy production costs than actual wind farms (by a factor up to 10-20) and could generate up to 250 MW/km2, vs. 3 MW/km2 of wind farms.
With a kite area of 50 m2 , simulations give about 200 kW power generated with 12m/s wind speed. A wind mill of the same power is 40 m high, weights about 62 t and costs about 900,000 euros. The expected KiteGen weight and cost are about 8t and 60,000 euros respectively.
It is expected that a wind generator of this type will have a territory occupation much lower than a wind farm of the same power (by a factor up to 50-100) and much lower electric energy production costs (by a factor up to 10-20). In the first step of the KiteGen project a small scale prototype has been realized (see Fig. 1) to show
the capability of controlling the flight of a single kite, by pulling the two lines which hold it, in such a way to extract a significant amount of energy.
The first tests performed on the built prototype in the yoyo configuration show a good matching between simulations and experimental results as regards the generated power.
A single 500 m**2 kite with 12 m/s nominal wind speed and aerodynamic efficiency (i.e. CL=CD) equal to 12 would be able to generate 10 MW mean power. 100 such kites towing a 1500 m radius carousel would generate 1000 MW mean power with about 7-8 km**2 land occupation and with an estimated energy production cost ten times lower than the one obtained by fossil fuel thermal plants. Note that a wind farm producing the same mean power, using the present wind mill technology, would have a territory occupation of about 250-300 km**2 and an energy production cost 40-50% higher than thermal plants.
Kitegen control unit, for controlling figure eight flight of airfoil
Kitegen airfoil flight patterns
Proposed carousel of airfoils for a 100 megawatt class kitegen generator
Newer imagining of a large scale kitegen generator. A generator ring is pulled and the support structure stays in place
Chart of average wind speeds at different altitudes. 800-1200 meters is a sweet spot with less challenging altitude but strong winds. At 800meters, average wind speed is 7.2 m/s and generates 205 watts per m**2. this is four times the power that current 5-6 MW windmills can get at 80 meters height with 4.6 m/s avg wind and 58 watts per m**2. Every point on the Earth surface, on average, 800 m above it, has enough wind power to be exploited with a Kite Gen power plant for energy generation.
10MW superconducting wind generators are being developed over the next 30 months The Italian Kitegen pilot plant should also be completed by the end of 2008.
Kitegen still needs more funding Although they had some agreement with a utility to help cover costs.