Although hybrid and electric cars have been around for a while now, the aviation industry has been lagging behind in developing greener, cleaner planes. Apart from an electric light aircraft that completed its first test flight in April this year, we’ve not seen many other developments in low-carbon flight aside from ideas and promises, mainly because batteries haven’t been good enough. But now, thanks to improvements in lithium-polymer batteries, hybrid planes are slowly becoming realized, and an aircraft with a parallel hybrid engine has just been tested in the UK. What’s more, it’s the first plane to be able to recharge its batteries mid-flight, and it uses 30% less fuel than a gas-only equivalent.
The aircraft was designed and constructed by engineers at the University of Cambridge, who were funded by Boeing. The plane, which is based on a commercially-available single seater, uses a Honda 4-stroke piston engine in parallel with a lightweight electric motor/generator to drive the propeller. When a lot of power is needed, such as during take-off, the engine and motor are both required to power the plane. However, once the aircraft is cruising, the motor can be switched into generator mode, which either recharges the batteries-- 16 lithium-polymer cells built into the wings-- or lowers fuel consumption. A custom power electronics module controls the current to and from the craft’s batteries.
The demonstrator was tested out at the Sywell Aerodrome, near Northampton, England. The first tests involved a series of “hops” along the runway, but longer, evaluation flights at a height of 1,500 feet (457 meters) were also conducted. The team behind the plane is now conducting further tests to optimize the system for both performance and fuel economy.
Check out a video of the aircraft here:
While this is certainly an important step towards greener, low-carbon air travel, it will be some time before we see electric commercial passenger airliners taking to the skies. As explained in a news-release from Cambridge, if the engines and fuel in a jetliner were to be replaced entirely by batteries, it would only be able to fly for around ten minutes. But the technology may come around sooner than you think as Boeing is not the only company committed to helping reduce man-made CO2 emissions. Airbus, the French-plane maker, is aiming towards producing a hybrid airliner with 80 seats that could be used to make regional city hops. And in Russia, Tupolev, an aerospace company, is coordinating 100 institutions and companies in order to develop an electric aircraft based on one of their passenger jets.