There are over 9700 commercial jets in the air at any given time. All of these planes run on specialized jet fuel, but with electric cars becoming more prevalent, why haven’t planes followed along? Electric vehicles have been around for a long time. In fact, some of the first cars used a primary cell back in the late 19th century. It seems foreseeable that all transportation in the future will be electric, but when will this future come?
Boeing, the biggest company for making commercial airliners, has recently started to experiment with electric aircraft. The Verge’s Andrew Hawkins reported on one of these aircraft that are capable of carrying few passengers and taking off vertically, similar to a RC drone or helicopter. The test flight conducted was pilotless and was only airborne for less than a minute. The purpose of a vehicle like this, would be a “flying taxi,” carrying passengers around a city or downtown area. There is talk that this electric aircraft will be used by Uber for the new “Uber Air” concept, that is planned for 2023.
That could very well lead to electric air travel going longer distances in the future — but this doesn’t quite cut it for long distance flight. A commercial flight to Hawaii from LA is over 4000 kilometres. But is there a sustainable and efficient battery that can carry an airliner full of people that far? Hawkins, notes that flying takes vast amounts of energy, and “present battery technology doesn’t offer the power-to-weight ratio in order for liftoff.” The nearest possibility for electric powered commercial flight will be in “years, if not decades.”
That may be true for the major airlines, but shorter flights with smaller planes face lower barriers to make the transition. Indeed, Harbour Air, an airline based in Vancouver that offers flights around the Pacific Northwest, has plans to go all electric by 2022. The planes carry maximum 10 passengers, are lightweight and travel small distances compared to airliners, making electrification easily doable. While this is a small company, they fly over 500,000 passengers a year and electrification will not only save money in the long term but also reduce emissions in the lower mainland of British Columbia.
The battery technology we currently have just does not produce enough power per pound for large aircraft. A YouTuber whose hobby is building aircraft and vehicles, Peter Sripol, shows how he uses 9 large energy cells about a foot long for a small, one seater propeller plane. But a large airplane full of passengers flying from Vancouver to Toronto will burn around 75,000 litres of fuel. That’s over 2.6 trillion joules of energy, almost 30,000 times more than a cell of an electric car. A battery of that capacity would be massive, heavy, and possibly too big to be stored in the average airliner.
To make larger electric planes feasible, there will need to be new kinds of batteries, and NASA is helping to fund their development. According to Clean Technica, NASA is funding research at the University of Illinois to develop liquid hydrogen energy cells for use in aircraft. Researchers at CHEETA, or Center for Cryogenic High Efficiency Electrical Technologies for Aircraft, had the idea of using liquid hydrogen cells to produce electricity, but converting the liquid hydrogen to energy is very difficult. Ian Randall writes, “At the moment, however, the electrical systems needed to connect such power sources to electrically-driven propulsion technologies and then apply such within a large aircraft have not yet been effectively realised,” meaning the equipment is not good enough yet to transfer that hydrogen energy to propel a large jet. NASA has also released plans for an electric plane using thousands of small lithium-ion cells: the X-57.
The future always holds the possibility for innovation in technology. Airplanes are getting faster and more efficient than ever. However, until we get a lighter, more powerful batteries, electric airplanes will remain just over the horizon.