Micro-hybridisation: the next frontier to electrify flight?

Q. In which applications could micro-hybridisation have the most impact?

In the near term, it's most suited to powering non-propulsive functions, such as air conditioning and cabin pressurisation, communications, flight controls and landing gear.

We could also use micro-hybridisation for certain engine functions on the ground and even in the air. Right now, commercial aircraft rely on an auxiliary power unit - a small gas turbine - to deliver power on the ground and to help start the main engines. Batteries could relieve this in a more sustainable, fuel-efficient way.

And while current battery technology doesn't have the right energy or power-to-weight ratio for intensive operations like take-off and cruise, we could use electric power to assist the thermal engines during taxi and descent.

Q. What would be the main advantages of electrifying an aircraft's functions?

Any process that draws energy from a battery instead of a thermal engine will reduce emissions by eliminating the need to burn fossil fuels. We estimate that micro-hybridisation could reduce an aircraft's environmental footprint by between 1% and 6%. For helicopters, it could be as much as 10%. Electrical systems are also typically easier to maintain than mechanical ones, which is another advantage. Lastly, micro-hybridisation could be an enabler for autonomous flight systems and connectivity technology, which will become increasingly important in the future.

Q. Does micro-hybridisation have applications beyond commercial aircraft?

Yes, it could be hugely beneficial for helicopters. Because they're smaller and lighter than fixed-wing aircraft, there's more immediate potential for battery-electric power to make a greater impact. Operating one engine on a twin-engine helicopter on electricity, for example, could reduce fuel consumption by between 15% and 25%. Military aircraft, too, could potentially implement micro-hybridisation techniques.

Ultimately, at Airbus, we aim to apply micro-hybridisation in a modular way across all our relevant products. Battery technology is evolving quickly, so it's vital to get the architecture right today. In doing so, we can easily adapt as battery technology matures.