Electric Airplanes: How Short Distance Flights Can Be Made on Batteries
Electric aircraft may seem futuristic, but currently it is not impossible to create, at least for short flights.
The Velis Electros two-seater electric plane has quietly flown in Europe, an electric seaplane is being tested in British Columbia, Canada, and larger electric planes are coming soon. On September 15, 2022, Air Canada announced that it would purchase 30 hybrid-electric regional aircraft from Sweden's Heart Aerospace with 30 seats in service by 2028. Analysts at the United States National Renewable Energy Laboratory noted that the 50- to 70-seat hybrid-electric commuter aircraft Firstly, it will soon be ready to fly. According to them, electric aviation could really take off in the 2030s.
This has important benefits in managing climate change. About 3% of global emissions come from aviation today. With the number of passengers and flights set to increase as the population grows, aviation could produce three to five times more carbon dioxide emissions by 2050 than before the COVID-19 pandemic.
Aerospace engineer and assistant professor Gökçin Çınar developed sustainable aviation concepts, including hybrid electric aircraft and hydrogen fuel alternatives, at the University of Michigan, United States. We asked him about the main ways to reduce aviation emissions today and where technologies such as electrification and hydrogen are headed.
Why is it so difficult for aviation to use electric power?
Airplanes are one of the most complex vehicles. However, the biggest problem with flying a plane on electric power is the weight of the batteries.
If you tried to fly a Boeing 737 aircraft completely on batteries today, you would have to remove all the passengers and cargo to fill that space with batteries just to fly less than an hour.
Jet fuel can store about 50 times more energy than batteries per unit mass. This means you can have 1 pound (0.4 kg) of jet fuel or 50 pounds (22.7 kg) of batteries. To close that gap, we need to make lithium ion batteries lighter or develop new batteries that can store more energy. Although they are being developed, these new batteries are not quite ready for airplanes.
An alternative to electric aircraft is a hybrid
While we may not be able to go all-electric for Boeing 737 aircraft, we can use hybrid propulsion systems to gain some of the fuel-burning benefits of batteries in larger jets. We are trying to make this happen in the short term, with a target of 2030-2035 for smaller regional aircraft. The less fuel burned during a flight, the fewer greenhouse gas emissions.
How does hybrid aviation work to reduce emissions?
Hybrid electric aircraft are similar to hybrid electric cars in that they use a combination of batteries and aviation fuel. The problem is that no other industry has the weight restrictions that we have in the aerospace industry.
This is why we have to be very smart in determining how and how much we hybridize propulsion systems.
Using batteries as power assistance during takeoff and flight is a very promising option. Taxiing the runway using only electric power can also save significant amounts of fuel and reduce local emissions at airports. There is an optimum point between the additional weight of the battery and the amount of electricity that can be used to get the benefits of clean fuel. This optimization problem is the focus of my research.
Hybrid aircraft will still burn fuel during flight. However, this fuel will be much less than relying entirely on jet fuel.
I see hybridization as a mid-term option for larger jets, but it being a short-term solution for regional aircraft.
For 2030 to 2035, we focus on hybrid turboprops, which are typically regional aircraft with 50-80 passengers or used for cargo. This hybrid can reduce fuel use by around 10%.
With electric hybrids, airlines can also utilize more regional airports which will reduce congestion and the time larger aircraft spend on the runway.
