How do electric aeroplanes work?

Inside the aircraft that’s leaving smaller carbon footprints in the sky than hi-octane jets

Right now, there are an estimated 20,000 aeroplanes in use around the world. Around 3 billion people travel on these planes, which account for four per cent of all greenhouse gas emissions. By 2040 it is thought that there are going to be more than double this number in use.

To control the impact this could have on the Earth’s climate, electric aircraft are providing a more sustainable solution to air travel. Electric engines have been designed in an attempt to create an emission-free air industry.  In today’s connected world, there is a growing demand for air travel, so work needs to be done quickly to counteract the potential damage this demand could have on the planet.

Electricity can be used to power electric aircraft in a variety of ways, including batteries, ground power cables, solar cells and power beaming. Power beaming involves the wireless delivery of energy to the aircraft from a remote power plant: the most common methods of this are through microwaves or lasers.

Electric travel was previously regarded as a dream for the future, until encouraging progress began to be made. In 2016, Solar Impulse 2 brought the electric dream further into reality. The electricity-powered aircraft was the first of its kind to complete a trip around the globe, in a journey that took a full 16 months. During this time no fuel was burned: it was a zero-emission trip.

NASA’s e-aeroplane winner

The ‘Vapor’ aircraft is the brainchild of Tom Neuman, who won a 2015 NASA competition (Image source: Future PLC)

1. Stack of fuel cells

For propulsion, fuel cells are used to convert hydrogen into electrical energy. This produces more energy than a battery alternative.

2. Electric motor

Electric motors make planes cleaner and quieter. Positioning them on the plane’s tail instead of on the wings increases efficiency by 85–92 per cent.

3. Air-intake scoop

The air scoop provides cold air to the plane’s components. It can also be used to ventilate the plane cabin.

4. Air compressor

Compressing the air from outside the plane maintains a constant pressure. The high-pressure oxygen reacts with the hydrogen to release spare electrons.

5. Hydrogen tanks

This is the same type of tank used in the Toyota Mirai electric car. The tank is both light and compact.

This article was originally published in How It Works issue 129, written by Ailsa Harvey

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