Boom Supersonic, the aerospace startup that will be manufacturing its carbon neutral jet in the Triad, will purchase 5 million gallons of sustainable aviation fuel per year from Dimensional Energy. But many questions about the fuel itself remain among some industry experts.
The contract is one part of the company’s net zero carbon commitment in the manufacturing of its supersonic airliner, Overture. One of the challenges for sustainable aviation fuel (or SAF) is supply — it accounts for less than one tenth of one percent of global fuels.
Boom Vice President of Sustainability Ben Murphy says that while the industry is still far away from seeing SAF scaled to full deployment, the landscape is changing.
"We’re seeing huge commitments from airlines and aircraft manufacturers, and so we really expect to see supply catch up to meet demand over the next 10 to 15 years," says Murphy. "And we really expect to see SAF being truly ubiquitous in the 2035 to 2040 timeframe when Overture’s fully operational."
In addition to its relative scarcity, SAF costs up to five times as much as fossil jet fuel. Murphy says the demand for SAF did not begin ticking up until 2020, and he’s confident that in time supply will catch up to demand and lead to price drops.
International Council on Clean Transportation Program Director Dan Rutherford is less optimistic about the economics of sustainable supersonic aviation, and — referencing a 2022 MIT study that he led — he questions the environmental impacts of SAF as well.
"If you take a sustainable aviation fuel, and you burn it in a supersonic aircraft that operates at a very high altitude, typically somewhere between 50,000 and 55,000 feet, you can actually have climate disbenefits," says Rutherford.
He says these impacts are due to the compositions of the fuels themselves. To that point, Boom’s Ben Murphy says SAF is an emerging science with nine different approved production methods currently in operation.
"One of the other key impacts that that MIT study omits is the benefits of contrail reductions," he says. "So, when you’re flying at the altitudes that we expect to cruise at, the air is actually too dry for contrails to form, and contrails are a significant factor in climate change."
According to its press release, in 2021 Boom achieved carbon neutrality through a combination of carbon credits and reduction initiatives.