Humans Invent met up with Dr. Stefano Longo, lecturer in electronic systems and control at Cranfield University and glider pilot instructor, who is working on a glider style wind turbine that could generate far more energy than current turbines.
Wind turbines are the best technology we have at the moment but the problem is that they are expensive to build
Longo says, “Wind turbines are the best technology we have at the moment but the problem is that they are expensive to build so the cost of the energy you get from a wind turbine at the moment is very high. On top of this, gliders will be able to generate more power where the wind is much stronger at high altitudes.”
A grounded approach
The energy generated by small propellers placed along the span of the glider’s wings will be conducted to the ground via a long, thin, cable. Makani Power, a US company, has already made an airborne wind turbine but, while Dr. Longo’s project is still in the theoretical stage, it will be set apart from others by what he calls, ‘online trajectory optimization’. Essentially, they plan to install a computer with a clever algorithm which will direct the plane to fly in a path where there are the strongest air currents.
Longo says, “It will fly in an optimized path calculated to overcome the constantly changing air conditions. It flies in a path that will maximize the energy it generates. The algorithm knows how the glider works, it has mathematical models of the physical processes such as power extraction, it measures the conditions around via sensors and it is able to do a prediction of future conditions. Once it makes the predictions it can take the best action in order to maximize the energy it is going to extract in the future.”
If battery technology makes progress then we can scrap the cable and have the glider recharging on-board batteries instead
Of course, the cable is a hindrance as it restricts how far the glider can fly but Longo says, “The gliders will fly around a confined space. They won’t go too far away because they will be able to harvest the local energy. It’s reasonable to think that they will fly in a circle of 100-200 meters diameter. If battery technology makes progress then we can scrap the cable and have the glider recharging on-board batteries instead.”
Though Longo concedes airborne turbines are still few decades away from becoming a commercial reality he hopes that it could prove to have a positive impact in developing countries when the technology is finally realised. He says, “I can imagine a house in Africa in the middle of nowhere with a glider flying on top generating power for that home.”