By Scott Hamilton
July 18, 2022 (BST), © Leeham News: Pratt & Whitney and sister company Collins Aerospace announced the launch of a hybrid-electric technology demonstrator, it was announced today at the Farnborough Air Show. This program is for future advanced air mobility vehicles.
Collins and Pratt & Whitney Canada, the turboprop engine unit, also announced the completion of the preliminary design of a 1MW motor for the demonstrator. A De Havilland Canada Dash 8-100 will be the platform for the commercial hybrid-electric application.
Called the STEP-Tech, this stands for the Scalable Turboelectric Powertrain Technology. This project is tied to the industry-wide goal of achieving net-zero CO2 emissions by 2050. It’s an ambitious industry goal.
The PW-Collins goal is to develop distributed hybrid-electric propulsion concepts in the 100-500kW sector. The propulsion may be scaled up to 1MW or more.
“In this space, you have a series and a distributed hydroelectric propulsion system,” explained Frank Preli, Vice President, Propulsion & Materials Technologies for PW, during a pre-Farnborough briefing. “We’ll have a turbo generator generating electricity and then that will be managed across one or more propulsors. In certain applications, you may have a dozen of these, for example.
“We’ll be doing our first ground testing later this year. Turbo generating makes the electricity. We will have a battery system as well and we can manage the power between the batteries and the turbo generator to power for propulsion units. That of course is all variable.”
“This is a project being run by Pratt & Whitney Canada (PWC), leveraging the capabilities of the whole corporation,” Preli said. The parallel hybrid electric is a system in which there is both a thermal engine and an electric motor-generator mechanically coupled to the turboprops.
“We can operate this propulsion system either on the motor-generator or the thermal engine or both. In certain parts of the mission, you’ll need all the power from both of those units, but in others, such as crews, you’ll only need power from the thermal engine,” he said.
“That engine can then be downsized and optimized for ultimate cruise performance. The overall mission energy use will be up to 30% lower than today’s turboprop aircraft through that combination and optimizing of the mission cycle,” he claims. Ground testing should begin this year, followed by a flight test in 2024.”
Collins completed the preliminary design of the 1MW electric motor for PWC, the companies announced at the air show. Testing already has been done. Prototypes will be sent to Canada soon.
“We are developing sustainable hybrid-electric propulsion technologies that will play an integral role in helping the aviation industry reduce carbon emissions to net-zero by 2050,” said Henry Brooks, president, Power & Controls for Collins Aerospace. “Together, we have the opportunity to truly redefine aerospace with greener solutions that will benefit not only our industry but our world as a whole.”
Reduce emmision using hybrid technology, thats what Collins is aiming for. More realistic than the parrots committing to zero emmisions for after they have retired. The green washers.
@Keesje
Excellent comment and I totally concur. These two companies are on the right track. Practical aviation sense.
Except it is no viable.
Well it is in the limited way they suggest-
‘That engine can then be downsized and optimized for ultimate cruise performance.’
They describe it as-
‘ parallel hybrid electric is a system in which there is both a thermal engine and an electric motor-generator mechanically coupled to the turboprops.’
Seems to be aimed at the peak power requirement for a twin engine plane at takeoff which then loses an engine and needs to continue the takeoff. The motor generator covers the loss of engine case and some of the extra power needed for takeoff.
The energy savings seem to be from using a much smaller turboshaft engine. But of course a whole of system approach means it is carrying heavy batteries and motor generator as well.
Worldwide, savings from improved fuel efficency on smaller turboprops dont add up to much
The fact that the aircrafts takeoff field length requirement is less sensitive to engine failure (though not prop failure) is interesting. I would imagine it might have advantages in hot and high conditions, good engine responsiveness for STOL approaches, resistance to bird strike & volcanic ash. The motor-generator replaces the starter & alternator so maybe not such a big gain in bulk. In the case of fuel depletion will allow a little manoeuvring. The only electric battery that can compete with liquid fuels are likely to be aluminium air batteries and this might allow a possible way into such vehicles.
P&W of Course will be happy to turn those offerings into Turbine Powered ground based generators.
Lot of applications for that (ie, see GE and the LM2500 and larger as well as RR with its offerings in the same class as main engines for Warships)
Distributed electrical is a wave of the future for power hungry warships as well as main power for smaller warships
Just noticed the large cabin belly fairing. This seems to be for the undercarriage , which would have been relocated from the under wing engine fairing.
As its a parallel hybrid , the motor generator is below the turboprop proper – where the undercarriage used to be.
The weight and balance seems to require more mods than you would expect
Will be very much interested to work with P&W on Turbine Powered ground based generators.
Seems like Heart Aerospace has selected 2ea PWC turbo generators for its ES-30 design. Most likely in the 125-500kW class. I assume the power controllers and transformers will be back in the non pressurized area behind the aft bulkhead like a twinpack mini 787 APU setup. The battery pack under the floor and Jet fuel in the wings. Then 4ea fat cables to provide power to each engine, most like one generator powering engine 1&4 the other engine 2&3. Will be fun if the throttles in the cockpit are old style like on a Super Constellation. Don’t know if PWC has given price and mass for the whole system yet including motors and prop system, (They have a tradition of big, black and heavy…)