First Look: Airborne Wind Turbine Prototype
April 28, 2012
If you thought you’ve seen the last word in wind turbine design, think again.
From a distance it looks like an escaped party balloon in the shape of a donut, but that new thing up in the skies over Limestone, Maine this winter was in fact the 35-foot prototype for a new helium blimp capable of harvesting wind energy at high altitudes, built by the company Altaeros. High-altitude winds are generally stronger and steadier than those near the surface, making them a more efficient feedstock for wind turbines than the low lying winds harvested by conventional wind farms.
How not to harvest wind energy at high altitudes
Building taller wind turbine towers is not a particularly cost effective way to grab high-altitude winds, due to additional expenses for site acquisition (larger towers generally require a larger footprint), manufacturing and transporting the components, constructing the tower, and performing routine inspections as well as maintenance and repair.
The benefits of blimp-lofted wind farms
Altaeros Energies, which calls its new blimp the Airborne Wind Turbine, is one of several companies working around the problem by sailing a turbine into the air (other attempts include hookups between wind turbines and kites).
Along with the benefits of gaining high altitudes without the need for a tower, the dock for the new blimp fits on a trailer for easy portability. The blimp’s tether doubles as a power transmission line and in case of severe weather, the blimp could be grounded by remote control.
Altaeros’s Airborne Wind Turbine
In the test this winter, the Airborne Wind Turbine prototype was lofted 350 feet high, carrying within its donut hole a popular Skystream model turbine from the firm Southwest Windpower. As anticipated, the blimp-mounted turbine generated more than twice the power than it would have if attached to a tower at a more conventional height.
Initially, the company’s goal was to attain a working height of up to 2,000 feet (by comparison, the Empire State Building is 1,250 feet high) and to develop a production model that could be transported in a standard shipping container and installed in just a few days.
So far tests indicate that a height of only 1,000 feet would be sufficient to gain a significant savings over conventional wind power. Within that parameter, Altaeros estimates that the energy produced by its turbine would cost up to 65 percent less than a comparable ground-sited wind turbine.