Siemens develops most powerful electric aircraft motor ever

Posted on 25 Mar 2015 by Michael Cruickshank

Siemens has debuted a new electric aircraft motor that is five times more powerful than other motors in its class in terms of its power-to-weight ratio.

Weighing in at just 50kg, the motor has a continuous energy output of 260kW and Siemens believes that the newly developed engine will open up new possibilities for electric-powered flight.

The German engineering firm envisages that aircraft with a total weight of up to 2,000kg would be able to be powered using the new electric aircraft motor.

In order to achieve this massive increase in power-to-weight ratio, Siemens scrutinised all parts of pre-existing electric motors in industrial settings and electric vehicles, and then optimised them to their technical limits.

Significantly, the new electric aircraft motor works efficiently at rotational speeds of around 2500 RPM, allowing it to be used to power aircraft propellers without a transmission.

“This innovation will make it possible to build series hybrid-electric aircraft with four or more seats,” said Frank Anton, head of eAircraft at Siemens Corporate Technology

Hybrid Aircraft

While the new engine can use purely battery power to run, Siemens sees it being more realistically implemented in so-called ‘hybrid’ aircraft.

Similar to hybrid cars, these aircraft would use a traditional fuel power plant to provide electrical power once batteries run dry.

“The plane would start purely electrical; afterwards a small combustion engine would produce electricity for the motor. The landing could again be purely electric,” explained Florian Martini, a spokesperson for Siemens.

Siemens is investing significantly in this technology, with a demonstrator electric aircraft motor fitted into a DA36 E-Star 2 motor glider by the company in 2013, proving the feasibility of the technology.

This aircraft, using an earlier motor only had a power output of 60kW. A much more powerful craft built using the new motor will be tested before the year’s end.

The company hopes to continue making even more powerful electric aircraft motors in order to make hybrid aircraft a realistic proposition.

“We’re convinced that the use of hybrid-electric drives in regional airliners with 50 to 100 passengers is a real medium-term possibility,” said Frank Anton.

Mounted on a specially modified truck the LEAPTech ground-test article, or Hybrid-Electric Integrated Systems Testbed, will be driven at speeds up to 70 miles per hour across a dry lakebed at Edwards Air Force Base - image courtesy of Nasa.
Mounted on a specially modified truck the LEAPTech ground-test article, or Hybrid-Electric Integrated Systems Testbed, will be driven at speeds up to 70 miles per hour across a dry lakebed at Edwards Air Force Base – image courtesy of Nasa.

NASA also working on electric aircraft

NASA is also said to be working on an ambitious plan to help a “significant portion” of the aircraft industry transition to electric propulsion within the next decade.

The space agency has begun testing an electric plane concept that uses Leading Edge Asynchronous Propeller Technology (LEAPTech). Designed in partnership with Empirical Systems Aerospace (ESAero) and Joby Aviation, the LEAPTech wing has 18 independently-operated electric motors powering 18 separate small propellers, which are powered by lithium phosphate batteries.