Kite balloons aim to harness the high-altitude energy of wind rushing 1,000m above earth. How viable is this technology?
Offshore wind farms, which receive so many press inches every year, are divisive for a reason. Working in the ocean requires a far more complex operation than a land-based farm, deciding on location often requires a certain amount of guesswork, and costs can spiral, putting off investors.
Also, there is the salient point that offshore wind does not even come close to being the strongest wind found on earth. That accolade goes to jet streams, air currents found in the earth’s atmosphere that can travel at speeds reaching 160km/hr.
Accessing this jet stream has up until now not been a possibility, but a technology developed over 70 years ago has the potential to utilise the speed of these winds as a dynamic new source of renewable energy.
‘Kytoons’, or kite balloons, were developed in 1944 and have been used for a variety of purposes, including civil and military. In the 1950s, they were packed in rubber life rafts to elevate the radio antennas of wartime flyers downed at sea.
The technology utilises the best bits of both a balloon and a kite. The kite action gives stability to a wayward balloon, which by itself would want to drift in a strong wind, and the balloon function, being lighter than air, helps to lift a kite that would otherwise nosedive in a strong gust.
The balloon is fixed to the ground by a set of cables, which are tethered to a control unit that converts the traction forces acting on the cables into electricity using generators.
One company involved in the technology, Cold Energy Systems, has said that the wind power available at 800m has about four times more power than current wind turbines operating at about 80m from the ground.
'They’ve turned a technology that today involves hundreds of tons of steel and precious open space into a problem that can be solved with really intelligent software'
It’s this potential power that venture capitalists and big names in the renewable sector are excited about. Bill Gates, who plans to invest another $1bn on top of the billion he has already invested in renewable energy, told the FT that some of the companies were “wild-eyed”, but added that “it’s great. I wish governments would help those guys out because there’s a 10 per cent chance it’s the magic solution.”
Currently, there are around 150 companies dedicated to some form of kite energy, although many of them are fledgling. The most known are Makani, which was acquired two years ago by Google, and Altaeros Energies, which has already tested a prototype at an altitude of 100m.
“They’ve turned a technology that today involves hundreds of tons of steel and precious open space into a problem that can be solved with really intelligent software,” Google X Director Astro Teller said at the time of purchase.
Though both companies are working at a very low altitude compared to the original premise of capturing the jet streams, the sheer volume of firms invested in this type of technology mean that heights are only set to increase in the future.