This is a part of the EV Innovation Intelligence series
In 2011, I was at a conference on biofuels at Orlando, Florida.
During one of the breaks, I caught up with a senior Boeing executive. We got chatting, and out of curiosity, I asked him what Boeing thought about use of biofuels in aviation. He said they were quite conservative about its prospects in the short and medium-term and said he would estimate that even by 2025, biofuels would not account for much more than 1% of the total fuels used for aviation.
That kind of squared with my views too. Then, without really thinking about it, I asked him what he thought were the prospects of electric airplanes. He just laughed.
There’s a reason why he did that.
Electrifying aviation will indeed be wonderful as the aviation industry is responsible for about 3% of total global GHG emissions, but it is no mean task. Batteries simply cannot compete with aviation fuel used currently – the latter have energy densities 30 times that of batteries. Imagine a large aircraft having to carry 30 times the current weight of fuel – it would never fly, and I mean not just metaphorically! (About 80% of the aviation industry’s emissions come from passenger flights longer than 1,500 Kms. – a distance not even electric airliners could hope to fly today, leave alone the Jumbos)
As Paul Eremenko, United Technologies chief technology officer said recently, “Unless there is some radical, yet-to-be-invented paradigm shift in energy storage, we are going to rely on hydrocarbon fuels for the foreseeable future”.
But yet, there is a buzz around electric aviation with a number of startups (and even some companies such as Hyundai) showing a keen interest in this. Why?
Hydrogen based electric aviation
One of the reasons could be that ten years from now, hydrogen fuel cell-based aviation could have become a reality. That quite changes everything, because hydrogen has three times as much energy density as fossil liquid fuels!
- ZeroAvia, a US and UK-based company developing hydrogen-electric engines. Using liquid hydrogen to feed fuel cells, the technology eliminates carbon emissions during the flight. With funding from UK government-backed bodies including the Aerospace Technology Institute and Innovate UK, ZeroAvia wants to plug the gap as aviation technology develops, and provide a sustainable solution for short and medium-haul flights. ZeroAvia claims that they will have hydrogen-powered commercial planes taking to the sky in just three years.
Battery energy density
Battery energy density in itself has been increasing, though I do not foresee how any type of battery can give a 30 fold jump in energy density in the foreseeable future. However, a 2x-4x increase in energy density might make batteries a feasible energy source for small airplanes servicing short distances, for instance for emergency trips across a city
- SVOLT, based in Changzhou, China, has announced that it has manufactured cobalt-free batteries designed for the EV market. Aside from reducing the rare earth metals, the company is claiming that they have a higher energy density, which could result in ranges of up to 800km (500 miles) for electric cars, while also lengthening the life of the battery and increasing the safety. Exactly where we’ll see these batteries we don’t know, but the company has confirmed that it’s working with a large European manufacturer.
- Li-S battery uses very light active materials: sulfur in the positive electrode and metallic lithium as the negative electrode. This is why its theoretical energy density is extraordinarily high: four times greater than that of Li-ion. That makes it a good fit for the aviation and space industries. Saft has selected and favored the most promising Li-S technology based on solid-state electrolytes. This technical path brings very high energy density, long life and overcomes the main drawbacks of the liquid-based Li-S (limited life, high self-discharge, …). Furthermore, this technology is supplementary to solid-state Li-ion thanks to its superior gravimetric energy density (+30% at stake in Wh/kg).
VTOL, flying taxis
Almost overnight, what we thought belonged to science fiction is becoming a reality. Flying taxis. Yes. Called VTOL taxis (vertical takeoff and landing taxis), these take off like a helicopter and carry the rich and wealthy across the city over traffic jams and land them ten miles away in no time. Small vehicles, short distances, once again these are feasible with batteries. (Taking this to the extreme, I recently even read about an electric flying suit – yes, you look like an electric-powered superman, but I suspect it is just fantasy, but who knows, that was what I thought about flying taxis too a couple of years back)
- Lilium, the five-year-old venture-backed startup from Munich,aims to have passengers taking regional trips in its electric five-seater aircraft starting in 2025. The Jet is not your typical aircraft: there is no tail, rudder, propellers, or gearbox. It has an egg-shaped cabin perched on landing gear with a pair of parallel tilt-rotor wings. The wings were fitted with a total of 36 electric jet engines that tilt up for vertical takeoff and then shift forward for horizontal flight. In final form, the Lilium Jet will have a range of 300 kilometers (186 miles) and a top speed of 300 km/h (186 mph).
- Volocopter is a leader in the urban air mobility space. As the first and only electric vertical take-off and landing (eVTOL) company to receive Design Organisation Approval (DOA) by the European Union Aviation Safety Agency (EASA), Volocopter expects its first commercial air taxi routes to be opened within the next two years. The velocity will become the first commercially licensed Volocopter, developed according to the high standards and requirements of the European Aviation Safety Agency (EASA) with a range of 35 km, max airspeed of 110km/h, and utilizes battery swapping technology.
Could fit specific types of aircraft
Flying taxis and similar vehicles such as small aircraft for emergencies could have a good business case to go electric, as it provides them independence from the need to access liquid fuel at short notice – it is far easier to get access to electricity, and with battery swapping, their concerns about dependence could be significantly reduced.
Drones & UAVs
Drones aren’t exactly aircraft, but they surely are airborne. Drones almost always use batteries for their power.
Same is the case with UAVs. UAVs once again have been prevalent for sometime, and UAVs use batteries as well
What do the big boys of aviation think?
As of yet, none of the aviation Big Boys – Boeing, Airbus, EASA, NASA, Bombardier, Embraer… – have said much about electric aircraft. It appears at the moment it is in amateur space. But who knows!
The aviation industry’s global climate action framework aims to reduce net CO2 emissions by 2050 by 50%. It surely is not betting on electric aviation to do this. The industry continues to take other measures to reduce its CO2 output.
- Development of sustainable aviation fuels made from waste and non-food feedstocks. These can be mixed with conventional aviation fuels and used in existing aircraft and airport fuel systems, without any technical modifications. It’s predicted that these fuels could reduce aviation CO2 emissions by as much as 80%.
- The aviation industry is also working hard on energy efficiency, by making the next generation of aircraft leaner, lighter and more aerodynamic so they burn less fuel and emit less CO2. Advances in air traffic control and new satellite technology mean shorter journey times and more efficient take-offs and landings, again cutting fuel consumption and CO2 emissions. On the ground, airports are introducing electric vehicles and terminals are being powered by renewable energy, making them much more energy efficient.
Factoids and updates from around the world on electric aviation:
- When electrified, small aircrafts (say, a turbo-prop Cessna), could be a lot cheaper to operate compared to these aircraft running on liquid fuel and traditional engines.
- Rolls-Royce, Airbus and Siemens are working on the E-Fan X programme, which will have a two megawatt (2MW) electric motor mounted on a BAE 146 jet. It is set to fly in 2021.
- For $140,000, you can fly your own electric airplane. The Slovenian company Pipistrel sells the Alpha Electro, the first electric aircraft certified as airworthy by the Federal Aviation Administration (FAA) in 2018. It’s a welterweight at just 811 pounds (368 kilograms), powered by a 21 kWh battery pack—about one-fifth the power of what you’d find in a Tesla Model S. For about 90 minutes, the pilot training plane will keep you and a companion aloft without burning a drop of fossil fuel.
This is a part of the EV Innovation Intelligence series
Posts in the series
Tesla’s Valuation | EV’s in different countries | Purpose built EVs | Mainstream Fuel Cells | IT in Emobility | EVs versus ICEs | Advent of China in Emobility | Charging vs Swapping | Micromobility & EVs | Electric Aviation | Li-ion alternatives | Million Mile Battery | Battery Startups versus Giants | Sales & Financing Models | Ultrafast Charging a Norm | Heavy Electric Vehicles | Material Sciences in Emobility | Lithium Scarcity | Solar Power in EV Ecosystem | EV Manufacturing Paradigm | Innovations in Motors | EV Startups – a speciality | Oil Companies’ Strategies | EV Adoption Paths | Covid-19 affect on the EV Industry |
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