Rolls-Royce has advanced its sustainable engine technology development with the start of tests on components for a planned 2.5-megawatt hybrid-electric motor.

Tests have begun in the UK on the AE2100 engine element and specialist controls and thermal management system, supported by a system integration generator. Separate testing of a 3,000-volt power electronics system is already underway in Norway, and later this year all the systems of Power Generation System 1 (PGS1) will be combined for full testing.

The system is designed to enable hybrid-electric regional aircraft or to contribute to more electrical output for larger aircraft.

“Our PGS1 tests will lead the way in finding out what this new generation of hybrid-electric propulsion system is capable of delivering,” said Alan Newby, director aerospace technology and future programmes, Rolls-Royce.

Late last year, one of the most influential voices in aircraft leasing, Air Lease chief executive Steven Udvar-Hazy, said that he expects the next clean-sheet aircraft from Boeing and Airbus to feature hybrid propulsion.

Udvar-Hazy sees hybrid propulsion as a transition to zero-carbon alternatives such as all-electric or hydrogen-powered aircraft, similar to what has occurred in the automotive market. 

Engine OEMs clearly agree, with Pratt & Whitney exploring the potential for a hybrid-electric version of its PW1000G geared turbofan.

Honeywell is also developing a power source for hybrid-electric aircraft, planned for demonstration later this year.

Based on its HGT1700 auxiliary power unit for the Airbus A350, the Honeywell turbogenerator generator will be able to run on aviation biofuel, and is being designed for missions from heavy-lift cargo drones to air taxis, or commuter aircraft. 

In late May, meanwhile, Russia’s United Engine said it plans to complete a demonstrator of its first hybrid-electric powerplant by 2023.