Catching a flight on a battery powered plane

Suppose, then, we find ourselves in a future of quick charging, high output, low degradation batteries. What avenues could that technology unlock? We already have battery powered cars and boats. But what about planes? Could we be charging off to a holiday destination in a battery powered airliner any time soon? Well that’s the thinking of the company Cuberg, a battery company based in California. Their founder is Richard Wang...

Richard - Ultimately the purpose for electrification primarily is to mitigate carbon emissions that come out of these various segments of transportation. But when you look at aviation, it also goes beyond that. That might be the primary motivation. But electrification brings a host of other benefits, including much lower noise profile, much lower operating costs when fully deployed at scale because of lower fuel and maintenance costs. And ultimately, this lets you actually apply aviation into a much broader array of flight routes, flying much more flexibly to smaller airports, smaller towns, and ultimately allow people to move around much more efficiently and cost effectively as well.

Chris - It sounds great, but the problem is that batteries are big. And if you look at, say, the average electric car, it weighs twice as much as a petrol powered car. So are you relying on improvements in battery technology to get you up in the air with this, or do you think that with even present technology, you've still got an opportunity to do this?

Richard - Our focus is on developing more advanced next generation forms of lithium batteries. To enable electric aviation, you ultimately do need quite a few different things from your batteries. Weight is the nameplate metric that is most critical, and ultimately it's both energy per weight and power per weight. So how far can you fly and can you get the energy out fast enough on takeoff and on landing, takeoff in particular for electric planes, to power your aircraft? And so you need a very special type of battery that does both very, very high energy and very high power in a relatively small weight package. And so that is what we are really focused on delivering. Of course, in addition to this, you also need reasonable cycle life and charging times. And at the end of life you need to be able to also recycle the battery effectively so that you have a fully sustainable solution. But ultimately, the weight of the battery and how much energy and power it delivers is the fundamental metric for success.

Chris - And when it comes to deploying this, how's it going to work? Are you basically going to have a slew of batteries in the bottom of a plane and they're going to supply a whole heap of motors on planes? And will it work in a way that one would recognise as an aircraft right now with say three or four engines? Or are we going to fundamentally redesign how aircraft work because we won't have to deal with the constraints of present jet engine technology, which has to a certain extent dictated how we build airplanes hitherto?

Richard - There are many, many different types of electric aircraft designs currently in development. And the reason for this is that this sort of natural selection and evolutionary process has not fully run its course yet. Typically these are not what you would think of as jet engine aircraft. They would be more reminiscent of propeller driven aircraft. And the difference is, yes, you have batteries and yes, you have electric motors driving propellers, but because you don't have a standard powertrain, you have cables carrying power. It's actually much more flexible to put a lot more propellers if you need to, wherever you want all around the aircraft. This lets you build aircraft that are much quieter potentially, much more energy efficient. And it also lets you build aircraft that are not only let's say standard small electric planes, but also some of these more unique concepts that are vertical takeoff and landing. So think of a helicopter, but with many more propellers designed for urban air mobility and that flies much more efficiently with much less noise compared to a helicopter.

Chris - One of the other big constraints with the technology we have at the moment with cars is how long it takes to charge them up. And many air operators, people who are doing fast turnaround passenger trips are turning their planes around in very short times. Can we recharge an electric plane in time or have you got another solution to that problem?

Richard - When you look at charging infrastructure, typically the two solutions are either to charge the battery in the aircraft or to try to swap the battery at the end of a flight. So far, what we've seen in the industry is most companies prefer to charge their aircraft rather than swap because swapping introduces a host of technical and regulatory challenges. And so charging time, it turns out that it's not as critical as an automotive where you're on a road trip and you're just sitting in the car waiting for it to charge fully before going again. In a typical electric aircraft business model, typically you fly to your end destination, you get off the aircraft, and then while the aircraft is on the ground, you plug it in, you actually have to clean the aircraft, you have to load passengers, unload passengers, load and unload cargo, do check-ins and so forth. And so given how these aircraft are operated, fast charging is still important, but not as critical as in the automotive industry.

Chris - Over what sort of time scale are you hoping to do this?

Richard - We believe that many of these industries will electrify by the end of this decade. Although to varying extents in aviation, we see a dramatic transformation of the aviation industry, particularly for smaller electric and hybrid electric aircraft flying up to a few hundred miles of range whereby by 2030 we will likely see the majority of these aircraft becoming fully or partially electrified.

Chris - And the environmental impact, will this be better?

Richard - It will be dramatically better for two key reasons. One is that electric motors are much more efficient in terms of energy use, compared to combustion. Roughly two to three times more efficient. So you're just using less energy when you're converting that into propulsion. And then in addition, of course, by using electricity, assuming you have a reasonably clean power generation grid, then you can also greatly mitigate the carbon content of the energy that's used for the flight itself. And so we're looking at very dramatic reductions in carbon content similar to what EVs are doing compared to existing combustion vehicles.

Chris - And finally, one of the most important considerations is how fast you go both for the convenience of passengers, but also the faster you go, the more drag there is and therefore the more fuel you burn at the moment with our present technology. So will we be looking at speeds and journey times with this technology, electrification, as equivalent to what we have at the moment with fossil fuels?

Richard - These kinds of electric aircraft will not be competitive with jet engine powered aircraft from a speed or from a range perspective. That will be other kinds of technologies like synthetic fuels and hydrogen to power future cleaner jet aircraft. If you look at battery aircraft, they will be propeller driven, but with that being said, they will be likely comparable from a speed perspective with existing propeller aircraft. The benefit is that with electric aircraft though, they're much more flexible. And so rather than going into a very, very big international airport to fly where you want to go, even if you're not going very far, you can get into a small local airport with much more efficient check-in times and security lines and everything else. And that I think, practically has a much higher benefit in terms of time savings compared to the aircraft itself.