Rolls-Royce has started testing the first elements of the most powerful hybrid-electric aero power and propulsion system in aerospace at its newly-renovated testbed.The tests are part of the 2.5 megawatt (MW) Power Generation System 1 (PGS1) demonstrator program for future regional aircraft.Rolls-Royce has begun testing the AE2100 engine element and specialist controls and thermal management system, supported by a system integration generator, at its Testbed 108 in Bristol, United Kingdom.Later this year, a fully operational generator and a 3,000-volt power electronics system, currently completing testing, will be brought together to start full PGS1 system testing. The generator can be used either for hybrid-electric propulsion systems or as part of a "more-electric" system for larger aircraft.PGS1 forms an important element of our sustainability strategy, which includes developing innovative electrical power and propulsion systems, as well as further improving gas turbine performance and promoting the use of Sustainable Aviation Fuels.Alan Newby, Director Aerospace Technology and Future Programmes, Rolls-Royce, said, "We are bringing together a system that promises to be truly ground-breaking in the world of aviation. We know that in a post-COVID-19 world, people will want to connect but do so more sustainably. Electrification offers a new way to power short-haul aircraft and we want to be at the forefront of pioneering this technology."Our PGS1 tests will lead the way in finding out what this new generation of hybrid-electric propulsion system is capable of delivering. For example, our generator is about the size of a beer keg, but it needs to produce enough electricity to power around 2,500 homes and do so continuously. By doing these tests, we will be able to validate our digital modeling and find out precisely what is physically and technically possible."Once ground tested, PGS1 will then provide a technology basis for any future hybrid aircraft program requiring MW power.