The advancement of Electric aviation is directly proportional to the weight and capacity of the batteries used. And that my dear friends is whats improving and hence the feasibility of the beast. Great efficient electric motors combined with great efficient batteries can only make this possible at scale and commercially. Tiny planes for short hop and fun with this tech are already available in the market. Going big and far is the concern here.
Challenges of Electric Aviation
- Low energy density of the batteries is the primary problem. Jet fuel has about 50 times more energy density than commercially available lithium ion batteries.
- Then there is the issue of range. Batteries can only keep the aircraft up in the air for a short bit before the juices run out nevertheless the technology is improving and so is the the capacity of the cells.
- Battery failures which can even cause fires are being studied as we go along.
- The literal bulk of the batteries as well as the fixed shapes make it hard to accommodate them in the frame unlike fuel which is liquid plus their weights reduce as they are being consumed.
Advantages of Electric Aviation
- No direct air pollution. Please note batteries have to be charged some how so using clean source is also important but clean they are.
- No engine noise. So airports can be located in populated areas.
- They are more efficient and more reliable than fuel burning engines. There are less chances of mechanical issues.
Some interesting ways of achieving electric aviation
- Solar panels on the body of the aircraft to convert sunlight. Typical solar panels running at 15-20% conversion efficiency produce about 200 W/m2 in direct sunlight. Also in recent times the cost of this tech has come down considerably making it very viable.
- Fuel cells with hydrogen chemically oxidized to produce electricity.
- Shooting microwave beams at aircraft to provide them with power, from power stations on ground is another futuristic looking technology that is possible and opens a bagful of possibilities and complexities.
Companies making electric planes
1 . Pipistrel
This electric plane company comes from Slovenia. The two seater has started out as a training aircraft and only costs about a $150k. It can cruise for an hour and has a range of over 200km. It has sold over 1300 units in over 90 countries. Their Alpha Electro is the first FAA-certified electric aircraft flying in the United States.
They have named it ‘Alice’ and the 9 seater commuter plane is due to be released in 2022. This Israeli aircraft has a range of 440 Nm and a carrying capacity of 2500 lbs. With Cape Air putting an order the demand for this aircraft is already hot.
They propose more of a hybrid solution by retrofitting one of the engines of a Cessna Skymaster with their electric engine. The range with the batteries alone will be over 200 miles while combined the cost of the fuel comes down by upto 90%.
Others like the giant Airbus, magnix, ByeAerospace etc are also trying their hand at making electric airplanes.
As of 2019, the best Li-ion batteries available achieved 250-300 Wh/kg which is sufficient for a small aircraft, while a regional airliner would have needed a 500 Wh/kg battery pack and an Airbus A320 sized single aisle would need 2 kWh/kg. Electric power so fare seems only suitable for small aircraft while for large passenger aircraft, an improvement of the energy density by a factor 20 compared to li-ion batteries would be required so may be hybrid solutions are way forward for them. The battery industry is also warming up with Tesla and other innovators so within in a few years this this aid greatly to the range of electric planes.
There are plenty of companies pursuing it and the tech around it is also improving so it is fair to say that electric aviation is a good possibility albeit a few years from now.