Electric Airplanes
Aviation emissions
Airplane carbon dioxide emissions are about 2.5% of global carbon emissions. These emissions are increasing, and reducing them will be difficult.
Graph showing the growth of aviation emissions from 1940 to 2020: World Economic Forum: Dec 2022.
Energy density problem
| Fuel | Energy density: Watt-hours / kilogram |
| Petrol or Jet fuel | 12,200 |
| Lithium-ion battery | 250 |
| Lead acid batteries | 40 |
Jet fuel holds about 49 times more energy per kilogram than a lithium-ion battery. This means that a plane powered by lithium-ion batteries must carry 49 times the fuel weight as the jet fuel needed for the same flight. Also, the jet fuel plane burns its fuel and lands with a lot less than eight, whereas the battery plane does not lose this weight. Batteries get too heavy for long flights.
Electric planes are here, but they won’t solve flying’s emissions problem: The Conversation: 6 Nov 2019.
Electric planes
The good news is that we do have:
- two-person electric planes, and
- larger electric planes are emerging.
Pipistrel: Velis Electro
In June 2020, the European Union Aviation Safety Agency achieved a groundbreaking milestone by issuing the world’s first “type certification” for a fully electric aircraft: the Pipistrel: Velis Electro. Certification for electric planes is typically lengthy due to their novelty and the rapid evolution of the technology. Remarkably, the certification process for this aircraft was completed in just three years. As a result, commercial electric flight has been a reality since 2020, marking four years of progress in this field.
Pipistrel makes a range of planes, including the battery-powered Velis Electro:
- A two-seater
- Approved for pilot training in over 30 countries
- Flight time up to 50 minutes plus 10 minutes of reserve
- Liquid-cooled lithium battery
- Charge with a Pipistrel battery charger and 3-phase 380-volt alternating current.
- Charging from 35% to 95% takes 80 minutes
- Low fuel costs and maintenance
- The quiet motor allows more flights near urban areas
- Zero carbon emissions during flight
- Developed from an earlier model: the 2007 Taurus Electro
Consider the weight of this plane,
| Weight without batteries | 288 kg | 48% |
| Battery weight | 140 kg | 23% |
| Maximum load including people | 172 kg | 29% |
| Total: Maximum take-off weight | 600 kg | 100% |
The battery uses 23% of the maximum take-off weight.
Pipistrel Velis Electro: Top Gear Review: Feb 2022
Pipistrel Velis Electro: Wikipedia
Electric planes in Australia
We have some of these Pipistrel electric planes in Australia.
The Perth-based company FlyOnE imported three Pipistrel Alpha Electro electric planes. They use these planes for private hire, pilot training, and sales demonstration.
Electric planes and emissions: ABC News: 5 May 2024
Alice: an all-electric plane
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A nine-passenger electric plane with a range of 1,000 km had its first test flight on 27 Sep 2022. It flew for eight minutes.
Eviation is still developing this plane, Alice, and has orders for 160 planes. They have designed it to:
- carry nine passengers and 2 crew
- fly up to 1,000 km,
- Maximum take-off weight (MTOW): 6,350 kg
- Battery weight: 3,720 kg, 59% of MTOW
- Lithium battery
- Charging via mobile charging vehicles, like aviation fuel trucks
- Charging time: 30 minutes per hour of flight
- cruise at 240 knots (444 km/hour),
- cut maintenance and fuel costs to about 30% of conventional planes.
How this electric aeroplane could reshape regional air travel: Renew Economy: 13 Nov 2018
All-electric jet firm Eviation announces US regional airline as the first customer: American Consumer News and Business Channel (CNBC)
MagniX to power Alice the Eviation electric aircraft: The Driven: 22 Apr 2019
Eviation: Alice: Wikipedia
Electrified Beaver seaplanes
Harbour Air in Canada electrified an old Beaver seaplane with a MagniX electric propulsion system. The plane flew 45 miles in 24 minutes in its first test fight on 10 Dec 2019, and by Aug 2022, it had done 70 test flights. They are now working to gain Canadian passenger flight certification for this plane.
Harbour Air carries half a million passengers a year. The electric planes will suit their business as their current planes carry 6 to 19 passengers, primarily for flights under 30 minutes.
Going Electric: Harbor Air: Canada
Seaplane to e-plane: Flight test confirmed: Harbour Air
Magnix
MagniX made the electric propulsion systems for the Beaver Seaplane and Alice. Although Magnix is now a US company, it started as an Engineering company on the Gold Coast in Queensland. Australia often has the know-how, but our companies frequently move overseas.
Aviation fuel in Australia
In the 1970s, Australia had many oil refineries. For example, BP alone had two refineries, one in Kwinana near Perth and another by Western Port Bay near Melbourne.
In 2024, Australia has only two refineries remaining: the Ampol Refinery in Brisbane and the Viva Refinery in Geelong. These refineries import most of their feedstocks.
As a large country, our security depends on the availability of this fuel, and we import about 90% of our aviation fuels.
Reducing aviation emissions
There are limited ways of reducing aviation emissions:
- developing lower emissions aviation fuels in existing planes,
- introducing planes using alternative fuels, e.g. electricity, hydrogen, and green methanol,
- improving plane design and engines,
- increasing operational efficiency,
- using trains rather than planes,
- reducing the need for travel, e.g., videoconferencing.
Summary
- We already have small, commercial, battery-electric planes: two-seater planes capable of flying for 1 hour.
- Larger electric planes are emerging,
- Reducing aeroplane carbon emissions will be difficult.
Updated 13 August 2024