From Bill Gates to biofuels to hydrogen fuel-cell powered flight
Last weekend, I purchased Bill Gates’ new book How to Avoid a Climate Disaster: The Solutions We Have and the Breakthroughs We Need. Even if you haven’t read it yet, you’ve likely seen it talked about on social media, on 60 Minutes with Anderson Cooper, and by clean energy advocates.
What you might not have seen is Bill Gates’ BBC interview with chief environment correspondent Justin Rowlatt, prior to the release of this book.
During the interview, Rowlatt lambasted Gates for the hypocrisy of travelling via private jets along with his recent bid to purchase Signature Aviation, the world’s largest private jet operator.
Rowlatt posed the question whether it’s “appropriate, given you’ve [Gates] just written a book telling the world how to avoid a climate disaster.”
To which Gates replied: “I don’t think getting rid of flying would make sense, that type of brute force technique won’t get us there.” Gates goes on to say that he pays “three times as much for aviation fuel” for his jet, which is powered by plant-based biofuels to the tune of USD $7 million a year.
According to Gates, the answer to decarbonizing the aviation industry has to be adopting “a fuel that doesn’t cost much extra and is zero emission, perhaps using green hydrogen to power planes.”
Certainly, travel by private jets is a far cry from the more environmentally friendly mode of transportation that influencer and fellow climate enthusiast Greta Thunberg opts for. This young environmental influencer is known to travel by sailboat to attend conferences and events.
But still, it made me wonder just how clean biofuel is, how feasible are the other alternatives, and what would it take to decarbonize the airline industry?
How airlines can chart a path to net-zero
2020 marked the airline industry’s largest decline in the history of aviation, with global capacity down over 75% due to the pandemic.
While in this current state of travel bans, the airline industry is receiving an unprecedented amount of government support.
And while most of the conversation has centred on the airlines’ survival, perhaps this time provides a unique opportunity for the industry to consider “building back better.”
To work towards creating a low-carbon future for itself—something that the industry has been contending with for some time now.
According to a McKinsey report, the innovation most transformative to the industry's carbon footprint will be adopting sustainable aviation fuel (SAF) like biofuels and hydrogen as an alternative to jet fuel. The jet fuel that is currently being used in the industry is a type of kerosene, which is a combustible hydrocarbon liquid derived from petroleum.
Transitioning to SAFs could reduce carbon emissions by 70-100% but would require the industry to make a case for immediate action if they plan to achieve carbon neutrality. The McKinsey report states that to achieve net-zero, the use of SAF would have to account for at least 20% of jet fuel by 2030. But just how realistic would this be, and what are the challenges?
Advanced biofuels
Biofuel is fuel made up of vegetables or waste oils. The first flight using blended biofuel took place in 2008 and since then, more than 150,000 have taken off successfully.
Still, annual aviation biofuel production of about 15 million litres only accounts for less than 0.1% of total aviation fuel consumption. Though this alternative fuel shows much promise, as its technical feasibility has been proven, getting an appropriate feedstock and supply chain in place has proven problematic.
Several studies have also linked biofuel development to environmental risks like deforestation. In addition to this, building production facilities and refineries are costly. Even the process of procuring used cooking oil is unreliable and expensive while other vegetable oils have high production, collection, transportation and conversion costs that have prevented widespread use.
Synthetic fuels
The use of synthetic fuels or “synfuels” is another scalable alternative created from hydrogen and captured carbon. The obvious set back is that they currently cost several times more than kerosene and are therefore not really a viable solution.
Until the economics of this clean alternative improves, airlines won’t be able to justify the business case required for widespread adoption. However, analysts predict a significant future savings in production of green hydrogen on the basis that technologies continue to improve, resulting in lower costs of renewable electricity.
The future of aircraft
While the spotlight has been on electric aviation (alternative propulsion) for the last decade, there are certain limitations that have restricted progress.
For instance, lithium-ion batteries are approximately 48 times less energy dense than kerosene. This really limits not just the distance that a plane can fly, but also the cargo it can hold, since a battery with a 100-mile range could weigh up to 2,000 lbs.
That means this type of travel will not be possible until battery technology improves significantly, which is why hydrogen is a much more viable solution since it's three times more energy dense than regular jet fuel.
Start-up companies like ZeroAvia are already thinking outside the box and retrofitting existing aircraft with hydrogen electric technology. Using liquid hydrogen to feed fuel cells completely eliminates carbon emissions during the flight. Last year, the start-up made history by flying the world’s first hydrogen fuel-cell powered flight for a commercial sized aircraft.
It’s clear that hydrogen holds remarkable potential to be the solution needed to decarbonize the aviation industry.
Will companies like ZeroAvia have first mover advantage when widespread adoption of this technology takes place? I certainly hope so, as it would incentivize more start-ups to mobilize quickly to get some skin in the game.
Uncertain optimism
Like Bill Gates, I am an eternal optimist who believes that people are capable of the most incredible feats of ingenuity.
But I also know that it will take more than innovation to decarbonize our most environmentally problematic sectors. It’s also going to take political will and intervention.
Luckily for us, young people like Thunberg are taking a fierce stand and their voices are being heard all over the planet.
The question now is when will political action follow?
Written by Susie Ho, former Senior Advisor at the Nuclear Innovation Institute.