Go fly a kite

California-based high altitude wind company Makani Power has embarked on another round of financing to develop a 1MW prototype of its energy-harvesting kite.

The company, which has previously raised $20m (£13.7m), plans to use large-wing kites, flying through the air at high altitudes, to harvest more energy than conventional wind turbines. According to the firm, conventional wind turbines, which are limited in their height, are unable to reach the high-speed winds available at higher altitudes. Higher-altitude winds can be used to produce a higher level of kinetic energy.

Makani says that high-altitude wind currents offer the highest level of energy per square foot. The company believes that capturing a small fraction of the global high altitude wind energy would be enough to supply the current energy needs of the entire planet. The company is designing kites which it hopes can harvest energy from wind streams at up to 600m altitude. The kites are flown by robots, enabling them to be kept aloft for long periods of time.

In tests conducted at its Maui site, Makani Power flew a piano-sized kite, which president and co-founder Saul Griffith said provided enough power for five average US households. The firm reckons it can double the power generated by a wind turbine while using only one fifth of the material.

The company, which hopes to close its funding round this year, plans on flying its first 1MW device in about 18 months. It will follow that up with another 18 months of testing before entering production, if all goes well. Chief executive Corwin Hardham has said that the technology is best suited for offshore applications.