A new IDTechEx report, Airborne Wind Energy (AWE) 2017-2027 finds that making electricity by flying kites and the like can potentially address two very different opportunities: to kill diesel or kill wind turbines.
The 20 leading AWE developers are mostly choosing one or other as their target. A few say they are chasing both opportunities. But since most of these small companies are underfunded, it is only a matter of time before they have to choose. These two objectives require very different products. This is despite the fact that the different variants – from tethered kites, semi rigid wings, fixed wings, rotor craft to turbines in balloons – all make cheaper electricity when bigger than they are now.
Another common factor across all these variants is higher power density than solar, but also potential for partnership with solar to reduce intermittency of supply.
The kill diesel option is more precisely defined as competing with diesel engines, kerosene heaters and fuel oil powered devices. This means being a replacement, or more often part of a replacement for the hassle, fire risk, pollution and legislative threat of diesel generator sets used by remote communities and as stand-by power for hospitals and so on.
Various researchers have been developing balloon supported wind turbines for years, but a project in Alaska is the first longer-term, commercial project to test the technology. Altaeros’ Buoyant Airborne Turbine (BAT) is an inflatable, helium-filled ring with a wind turbine suspended inside. It floats at a height of 300m, where winds tend to be far stronger than they are on the ground. The altitude of the BAT is about double the hub height of the world’s largest wind turbine with higher in prospect. The technology can be deployed in under 24 hours, because it does not require cranes or underground foundations. Instead it uses high-strength tethers, which hold the BAT steady and allow the electricity to be sent back to the ground.