Hybrid cars have been on our roads for years, switching between gas and electricity to save fuel. Now, the aviation industry is shifting towards that same technology.

Researchers at SINTEF and engineers at Rolls-Royce Electrical Norway are working on a hybrid aircraft engine that could change how we fly. This new engine combines an electric motor with a traditional combustion engine to spin a propeller. 

Company officials believe this new tech could cut CO2 emissions by up to 30 percent.

“The principle that causes emissions to decrease is the same as for hybrid cars, that is, a combination of both fuel and electricity,” said SINTEF researcher Torstein Grav Aakre.

Regional Flights Come First 

Hybrid engine
Representational image; Photo: Jose Miguel Sanchez/Shutterstock

Despite the progress, you probably won’t see a hybrid plane crossing the Atlantic anytime soon. The focus for now is on shorter, regional trips. The biggest hurdle right now is the engine’s weight. Batteries are much heavier than jet fuel, and the longer the flight, the more energy the plane has to carry.

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To make this work, everything on the plane needs to be as light as possible. Astrid Røkke from Rolls-Royce Electrical Norway said, “Everything has to be as light as possible in aviation, so one of our main tasks is to reduce the weight of the aircraft engine as much as possible.”

The “Heart” of the Hybrid Engine

The team is currently looking at the “stator,” which is essentially the heart of the electric motor. It uses coils to create a magnetic field that turns the rotor. These coils need insulation to prevent short circuits, but that insulation has to be incredibly thin to keep the weight down.

“The stator converts current that is sent through coils into an alternating magnetic field that turns the rotor,” Røkke explained. “The coils require insulation to prevent short circuits, and this needs to be as thin as possible, without compromising the insulation’s lifespan.”

Because these engines use higher voltages and frequencies than usual, the team had to invent a new way to test how long the materials will last. Without these tests, they wouldn’t know if the engine was truly safe for long-term use.

“The test method SINTEF has created is something that we’ve needed at Rolls-Royce for a long time, but that we haven’t been able to find or had the expertise to develop ourselves,” Røkke said. “In other words, SINTEF has solved a real problem for us.”

A demo engine is being built right now and will be tested in France next summer. If all goes well, these hybrid engines could be ready for the market by 2035.