Capture, accelerate, concentrate” is SheerWind’s mantra.
Wind enters intake vents arranged radially at the top of the Invelox tower. In the small-scale prototypes, this funnel-shaped structure was made of either steel or aluminium/steel architectural fabric, but it could be fashioned from other materials that can stand up to a site’s wind loads and weather.
As the wind travels down the tapering “runway”, it picks up speed due to the Venturi effect (a phenomenon in which the airflow is accelerated by its own changing pressure), boosting its kinetic energy as it approaches the ground-level turbine and generator set.
Channelling the wind from the top of the tower down to ground level allows for high-end power generation from small-diameter rotors: a 28-metre-tall Invelox with eight-metre blades should be able to go toe to toe with a traditional 1.8MW machine with a hub height of 90 metres and 85-metre-long blades.
SheerWind’s 50kW prototype in Minnesota ran at a capacity factor of 72% while flowing an average 314% more power than a like-rated horizontal-axis turbine.