Is the sky the limit?
Watching the automotive industry transition from fuel to electric has appeared seemingly sleek. Staggeringly, UK sales of electric cars in September 2021 neared the figures of the whole of 2019, with a whopping 33,000 electric cars registered. Though in part due to panic-buying at the petrol pumps, the appetite to make the switch to clean has never been more prominent. While electric cars are now the norm on our roads, up above we’re still heavily reliant on fuels with damaging carbon emissions. Is the sky, in fact, the limit for the electrification of transport?
How Does an Aeroplane Fly?
A quick Google of ‘how does an aeroplane fly?’ tells you that plane engines are designed to move it forward at high speed. Air flows rapidly over the wings then throws it down towards the ground, generating the upward force known as ‘lift’. Lift holds aeroplanes in the sky; the wings force the air downwards, pushing the plane upwards. So, if one of the two essential factors of getting a plane airborne is an already-occurring natural substance, why is creating environmentally-friendly engine power such an engineering and technological feat?
Well, like most things, it massively comes down to money. Broadly speaking, many industries have seen pockets tighten thanks to the pandemic. The economic outlook of the aerospace sector has somewhat shifted; the industry has gone from being able to rely on a usually-steady growth rate to experiencing sudden shrinks in size. Engineering accomplishments are one thing; financial trouble is another.
Flying Through Turbulence
However, in the words of Einstein ‘in the midst of every crisis, lies great opportunity’. As the industry begins to show some signs of recovery from the turbulent effects of the pandemic which grounded flights worldwide, there’s a whole ‘new norm’ of the aero-sector waiting to be discovered. That’s in terms of changing demands, business models, and no/low carbon emissions. Especially given that the UK is legally bound to its 2050 target for net-zero emissions.
And that could be why the Government has initiated a Jet Zero Council (JZC). Its goals? To accelerate the processes required to achieve zero emission aircrafts and aviation systems in the UK. From design and manufacture to testing and certification, the overall aim is to deliver the first zero-emission transatlantic flight within the timeframe of a single generation.
Whilst this aim is commendable, we’re living in an era where we’re used to being able to get super-cheap flights to virtually anywhere, at any time. You don’t need us to tell you the draw of jumping on a £20 plane to Prague on a Friday and getting home in time for the Monday morning meeting, but it’s not exactly promoting air efficiencies or allowing for reductions in air travel, is it? With global emissions from aviation predicted to grow 300% by 2050, it throws affordability into the picture. As well as whether there’s a legitimate argument for ‘cheaper’ airlines to be taking more responsibility for their flight emissions.
Ready for Take-off?
This brings us back to our main question: what exactly, then, is the limit? Well, there are some genuinely feasible options out there to decarbonise air travel. It’s just having the capacity, the investment, and the determination to really get them off the ground.
Much like the change from E5 to E10 petrol, the fuel used by airlines can be made more sustainable. Though more expensive than its alternative, it’s less costly to the planet. Currently, fossil kerosene is widely used, producing 3.15kg of CO2 for every kilogram used. Not to mention it makes up between 20 and 30% of operational costs! Sustainable air fuel has got mega potential to reduce carbon emissions by up to 100%, but presently it’s only accounting for less than 1% of total consumed jet fuel.
Improving the actual fuel we’re using is a start; following this is improving fuel efficiency. Decreasing the amount of ‘extra’ fuel loaded onto aircraft in combination with introducing lighter materials that reduce aircraft weight means that overall, less fuel is needed to power the flight. Less fuel equals a lesser environmental impact.
Looking to the future, electric or hydrogen propulsion will hopefully be advanced enough to replace fuel-powered planes. But it’s still a while-off yet. Given the lower energy density of batteries compared to fuels, aircraft would need to carry more than 50kg of battery weight to replace just 1kg of kerosene. Battery weight doesn’t ‘burn off’ like fuel does, meaning this weight would need carrying for an entire flight, requiring – you guessed it – energy.
So, like we’ve seen with vehicles, meeting halfway and empowering a hybrid model could be the interim answer. After all, it’s one thing experiencing range anxiety in a car, and completely another mid-air. Hybrid models promote a softer transition for the public to the once far-fetched idea of electric flight. What’s more, as jet engines incorporate hybridity, they become smaller and lighter, requiring less fuel and improving efficiencies.
A New Meaning of Air Traffic Control
Electrifying aircraft isn’t the only hurdle here; airports will require redesigns to accommodate the transformation. Refuelling processes will need to become recharging processes. Airport managers will need to assess site capacity to charge ten, twenty, one hundred planes simultaneously. Reliable contingency plans for electricity generation will need to be established in case of blackouts.
It’s safe to say there’s a lot to consider, and a lot to be done. Fortunately, to help support the green movement in the sky, the Zero Emission Flight Infrastructure has been established. Eligible businesses and universities are incentivised by up to £50k each to develop research into features that will enable the mass uptake of electric and hydrogen aircraft, like charge points and hydrogen fuel tanks. Green aircraft development might not be mid-air just yet, but it’s nearing the runway. We’re excited for the day when we can take our seat.