Rolls-Royce Hybrid-Electric PGS1 Reaches Megawatt Milestone


Rolls-Royce announced on Tuesday that its hybrid-electric propulsion system demonstrator has delivered more than a megawatt of power for the first time. According to the company, it is aiming to reach up to 2.5 megawatts with the Power Generation System 1 (PGS1) demonstrator as testing continues. PGS1 testing is taking place at the Rolls-Royce Testbed 108 facility in Bristol, U.K.

“We’ve made a tremendous start to testing—reaching a megawatt is a great achievement,” said Adam Newman, Rolls Royce Aviation Futures chief project engineer. “When future hybrid-electric aircraft opportunities emerge in the megawatt and above class we want to be as prepared as we can be to offer a ready-made solution.”

The PGS1 system includes an AE2100 engine, generator, specialist controls and a thermal management system. As previously reported by AVweb, the PGS1 generator was delivered to Testbed 108 last July following the completion of a development test program conducted at Rolls-Royce’s Trondheim, Norway, facility. The PGS1 program has been supported by the U.K. Aerospace Technology Institute’s MegaFlight project.

Kate O'Connor
Kate O’Connor works as AVweb's Editor-in-Chief. She is a private pilot, certificated aircraft dispatcher, and graduate of Embry-Riddle Aeronautical University.

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  1. Still, no value.

    A megawatt is 1,341 HP

    A turbofan engine, like on a 777, produces 52,000 HP

    Are they going to hang 39 of these things on each wing?

    • No, but they might hang one in the tail of a widebody. Also, RR makes turboprop engines in the 1000-1500HP range for aircraft already. Not everything is a 777.

    • The question is how much battery weight will be needed to develop this Megawatt of power.
      52,000 hp might not be needed to lift the truck loads of fuel… but then again it might be truck loads of batteries to run the thing.
      I’ve never been against battery power anything… if it makes sense. The truth is fuel powered lanterns last days longer than battery powered flashlights… but it makes more sense to use the flash light. Some day it may make more sense to use electric engines and batteries. Price, size, use, etc… will always be taken into account.

  2. Many mechanics are good with electrical tape and zip ties but often electrocute themselves changing batteries in their flashlights. I can just imagine THIS monstrosity confounding them …

  3. Good point Jim. I have to admit, I am struggling to understand the benefits of converting 100% of the mechanical energy generated by the turbine or piston engine into electrical energy before being applied to the same thrust producing device. There is certainly no gain in efficiency during this additional conversion stage and the additional component weight does not come without an additional penalty. These penalties alone should increase fuel burn per mile. Why again are they doing this? And why is there a market for it?

    • Since each system has inherent energy losses, there is a net decrease in overall efficiency. You can’t fool physics but apparently you can fool politicians rather easily.

    • Exactly. You can make a case for hybrid in a ground vehicle, where mission profiles typically have a highly variable power demand and may derive operational benefit from having the dual energy source. Aircraft, on the other hand, pretty much have a “gimme all you got & keep doing it” sort of power demand. Adding the conversion stages just trashes efficiency.

      I suppose you could come up with a specialized multi-thruster VTOL utility lifter-transporter application needing the distribution & fine control offered by electric power that would require a light and powerful generator.

    • Can we all just take a breath here? This is completely new technology, it’s going to take a while, and a lot of invention and failures, to get to the point where it’s operable. Based on the sarcastic remarks did you expected this to work right from the drawing board? C’mon!

      From the earliest days in aviation those on the sidelines made similar comments; they said airplanes were no more than kites and they had no foreseeable practical application or benefit. It took decades for us to get to where we are today and it happened through imagination and ideas. Some failed, but many succeeded -that’s what it takes. We need to make changes to our powerplants now, to make them run as clean as possible, we need to innovate and that takes time and iteration. I applaud the pioneers who invest their own time and money by innovating and frankly if the folks at RR and P&W are prepared to do it, I am confident that they have a better grasp on the physics than those on the sidelines.

      • It’s not new technology. People have been working with motors and batteries and generators for a very long time. You cannot bypass the laws of physics no master how much you wish you could.

  4. Hybrids, batteries, electric motors, and large gauge wires carrying high amp currents. Electric motors overheating. I foresee some really spectacular inflight fires with electric or hybrid powered aircraft.

  5. I stand corrected.

    It appears Tesla fires can burn for many hours and require tens of thousands of gallons to extinguish, so maybe the airplanes will burn for a long time also.

    • The volunteer fire department in my small town near Oshkosh has strict orders. If an electric or hybrid vehicle is on fire, yank the people out and drink beer while the car burns. The 1,200 lb battery pack in a Tesla oughta be a helluva roman candle, I’d say ?

    • Fire fighters don’t know how to fight chemical fires with water… wait… that doesn’t work on chemical fires 🔥 No wonder they burn so long… wrong extinguishing agent

      On that thought… I see far to many crashes that begin to burn long after the plane stopped moving. I can’t help but think… maybe someone is trapped. They do make fire extinguishers that work on their own when exposed to fire and will put out all classes of fire including chemical.
      If I build an experimental plane they will be installed on my aircraft in front of the fire wall. I can’t think of a more horrible way to go than burning alive.

  6. Railway locomotives have been doing it for years, using diesel pistons to turn a generator to power electric motors. Great advantage for a train is the max torque from the first to drive wheels.
    Not sure how max torque can be achieved with aircraft — maybe lots of extreme pitch propellers…

    • This is the point I have tried to make in a growing roster of comments…a transport airplane is not a locomotive, nor is it an automobile, truck, nor even a ship. Each has its own mission & mission profile. Injecting electricity, or any other energy transfer medium, into the “drive chain” makes sense only if it convers advantages. Otherwise, the process of converting from one energy transfer medium to another only introduces losses. Now, if injecting unnecessary losses is considered immaterial in the advancement of some socio-political narrative, well, that should be argued on that basis rather than trying to justify it within the context of physics.

      • John, well said. The object of the endeavor no longer seems to be speed, range, reliability or even overall system efficiency. When the objective is switched to political then we have these “flights of fancy” projects where the benefit is in the political realm but the product is arguably less efficient and less practical.