Air traffic accounts for some 2.2 percent of CO2 emissions worldwide. For this reason, aircraft, too, must become more efficient. One possible solution – which Siemens, Diamond Aircraft and the European aerospace firm EADS are testing in the DA36 E-Star motor glider – is to electrify the drive system.
To that end the world's first aircraft with a serial hybrid electric drive system is set to fly at the Paris Air Show (Le Bourget) 2011. The technology, which is intended for later use also in large-scale aircraft, will cut fuel consumption and emissions by 25 percent compared to today's most efficient aircraft drives, according to the manufacturers.
The motor glider, which is based on Diamond Aircraft's HK36 Super Dimona has a propeller powered by a 70kW electric motor from Siemens. Electricity is supplied by a small Wankel engine from Austro Engine with a generator that functions solely as a power source. A Siemens converter supplies the electric motor with power from the battery and the generator. Fuel consumption is very low since the combustion engine always runs with a constant low output of 30kW. A battery system from EADS provides the increased power required during takeoff and climb. The accumulator is recharged during the cruising phase.
The next development step will be to further optimize the entire drive train. Siemens says its scientists are working on a new electric motor that is expected to be five times lighter than conventional drives; iIn two years, another aircraft is expected to be equipped with an ultra-light electric drive.
The electric motor glider successfully completed its first flight at the Wiener Neustadt airfield in Vienna, Austria on June 8. The DA36 E-Star will be exhibited at the Paris Air Show Le Bourget in a flight demonstration every day from June 20 to June 26.