EU-funded researchers have developed a prototype wind energy system that works at much higher altitudes, where winds are stronger and more constant, dramatically increasing electricity production. A commercialised product is in the pipeline.
Most wind energy comes from turbines 150 metres above ground level. Winds at this altitude are however weak and intermittent, with most wind farms operating at only 25 – 30% of their capacity, the researches said.
The EU-funded HAWE system is a floating airship anchored to a ground station by a tether cable. The airborne module – or ABM – constantly rotates and is pulled upwards by an aerodynamic force known as the “Magnus Effect”. HAWE is a hybrid platform using buoyancy and lift. Its tether cable transmits this force to a generator at the ground station, where it is converted into electrical energy.
The system does not depend on high, exposed sites or coastal areas to operate, so it can easily be deployed out of sight, or in remote locations, both on and offshore – even in deep water.
The ABM’s altitude can be changed depending on wind speed to maximise energy capacity.
“As the system operates well over 200 metres above ground, any visual pollution is minimal,” adds project coordinator Nuno Fernandes from high-tech R&D company Omnidea in Portugal. “Also, construction costs are low as there is no need for giant steel and concrete towers.”
HAWE’s key features include a winch operating at speeds of up to six metres per second, plus a multifunctional cable able to withstand the ABM’s forces and capable of transferring high voltage power and data.
In addition, a dynamic communications and control system allows for automatic or semi-automatic operation.
According to Fernandes, intensive testing carried out at an air force base has validated the prototype and provided a sound basis for scaling-up the technology. And HAWE’s already low construction costs are expected to fall further as the project comes closer to commercialisation.
The lead partner Omnidea is actively looking at ways to propel HAWE to the next level, which would see a commercialised product available on the market.
The company has also identified some spin-off opportunities for a stationary platform that could be used in environmental and security monitoring; intelligence, surveillance and reconnaissance; wireless communication and satellite data validation.
Image: Omnidea