US energy startup Altaeros is looking to break the world record for the highest wind turbine, by launching one 305m into the air above Fairbanks, Alaska.

At such a height the winds are both more reliable and five to eight times stronger, and should therefore allow the helium-filled Buoyant Airborne Turbine (BAT) to produce more energy.

As the BAT is floating above the ground, it will have a reduced environmental footprint, and can be deployed in remote areas as well as disaster or conflict zones.

However, these benefits come at a price, with the BAT costing $1.3 million (£785,000), and its energy costing 18 cents (11p) per kilowatt hour compared to 4 to 5 cents per kilowatt hour for a traditional wind turbine.