Emily Pickrell, UH Energy Scholar
FILE - In this Friday, March 19, 2021 file photo, an airliner lands at Tampa International Airport ... [+]
As concerns about Covid-19 slowly fade, the skies are becoming friendlier again, with domestic flight traffic creeping up toward pre-pandemic levels.
But it’s not there yet.
By March 2021, passenger traffic increased by 30% from last month, and airlines say it may take a couple of years to fully recover, as remote workplaces continue to disrupt business travel and more folks travel locally.
Yet the full recovery of the airline industry is still within sight. Still, airlines must plan to meet their target goals of net zero carbon emissions by 2050.
Until recently, the industry mostly relied on increases in fuel efficiency for carbon reduction improvements.
Fuel is a large operational cost for airlines, and so economics play a powerful motivational role in optimizing fuel, even without the carbon implications.
Yet there are limits to what fuel efficiency can achieve in reducing the carbon emissions, given that jet fuel is typically made of fossil fuels.
Both domestically and internationally, politicians and customers alike are asking airlines to further reduce their carbon footprint. This comes from a growing awareness of the need for carbon reductions and = the aviation sector’s outsized carbon footprint.
Air travel comprises 2% of carbon emissions worldwide – a seemingly small number, but one that could grow rapidly without changes in the industry. Domestic flights are responsible for 9% of carbon emissions in domestic travel, making it one of the dirtiest forms of transportation.
Worse, most aviation emissions are in the upper atmosphere, so the impact is on climate change is greater.
To achieve net zero carbon emissions, the industry has started to adopt non-carbon emitting fuels – known as sustainable alternative fuels.
Sustainable alternative fuel can be made from a surprisingly wide range of materials. Crops and tree residues like switchgrass or wood waste can be processed through gasification, for example, with that gas then converted to synthetic liquid fuels, according to a U.S. Government Accountability Office report. Vegetable oils, animal fats and even algae oils have shown potential, as has separated municipal solid waste.
The challenge is getting enough of the fuel for an industry that in 2019 consumed 12 billion gallons of jet fuel for U.S. travel. Worldwide, U.S. jet setters burned through more than 18 billion gallons of jet fuel, about 20% of total global consumption.
At these consumption rates, sustainable fuels could eventually meet about 80% of the global carbon reduction target, according to the International Air Transport Association. It currently is targeting a carbon emissions reduction by 50 percent relative to 2005 levels by 2050.
It’s a strategy that U.S. airlines have shown a growing interest in as they make their own carbon neutral commitments.
As part of this, an industry group that represents most U.S. domestic carriers, Airlines for America, has been working to supply these sustainable fuels since 2006. They partner with the U.S. Federal Aviation Administration to develop industry standards for the fuel.
Airlines for America set a target of 2 billion gallons of sustainable fuel by 2030. It’s a steep upward climb from 2020 production levels at 4.5 million gallons.
A unique challenge is meeting rigorous safety criteria – much stricter than what ethanol or biodiesel fuel faced in their development and deployment. The reason lies in the extreme range of conditions under which airplane engines are required to operate.
“At ground level you are going to have a certain heat, you are going to go up in the air, you are going to be at 36,000 feet and it’s going to be pretty darn cold up there,” said Nancy Young, the vice president for Environmental Affairs at Airlines for America. “And at the same time, there has to be energy density to fuel the aircraft in the same way that petroleum-based fuel does.”
One decision made on alternative jet fuel standards is the need to be usable on existing jet engine technology. The alternative would have been to try to persuade the airlines to invest billions of dollars in rebuilding its technology to adapt to new fuel standards – a tough ask for the cost-conscious aviation industry.
As a result, standards were established to ensure the sustainable fuel would act as a parallel fuel, known in the industry as a drop-in fuel, which operates on a chemical level as a functional equivalent to jet fuel.
A big advantage of using sustainable drop-in fuels is that they can be integrated into the already existing airport and fueling infrastructure.
“Our plan is to drive alternative fuel producers to produce sustainable fuel that will work with the system that we have,” Young said. “At the same time, we work with the aircraft manufacturers, the researchers with NASA and others and a research portfolio that will advance opportunities for electric and hybrid electric aircraft and future non drop-in fuel sources, like hydrogen.”
Relatively high costs for the fuels need to come down, airlines say, in order to make them more feasible. Sustainable fuels on average cost about three to five times more than petroleum-based jet fuel.
Increasing = alternative fuel producers is another challenge – many likely candidates are already producing renewable fuels for automobiles but may not be equipped to make drop-in alternative jet fuel.
“Ground-based alternative fuel has a tremendous incumbency,” Young said. “If you’re a fuel producer, you’re already doing those other types. It takes you an investment to then do sustainable aviation fuel. And you care about what the federal and state incentives are that might help support that process.”
One idea for jump-starting production increases is a tax credit of $1.50 per gallon for alternative fuel producers, an idea that President Biden has included in his recently released budget proposal. It’s an increase from the $1.00 offered in previous tax legislation and is similar to tax boosts once given to the wind, solar and biodiesel sectors in order to encourage further investment.
“The aviation industry is saying we are in the early days of sustainable aviation fuel production – we have not yet been able to do the optimization on the supply chains and the production process itself,” said Steve Csonka, executive director of the Commercial Aviation Alternative Fuels Association. “We hope to come down the learning curve, but assistance with financing of some kind is needed to allow that to occur.”
The Biden proposal would make the credit available from 2022 to 2027 and would only apply to alternative fuels that can achieve at least a 50% reduction in emissions.
Yet while a presidential acknowledgement is a big step forward, much remains to ensure that these sustainable fuels – which are currently at less than .01% of global aviation fuel supply - can actually fuel an entire industry.
Sourcing feedstocks on a commercial scale need to be identified and established, facilities built and financed. Supply chain planning for feedstock is no small issue, especially if it involves growing crops, which means both intensive land and water resources. It will be a challenge to scale up while still ensuring the aviation fuel industry does not attempt to take over already committed water sources or land used to grow food.
Daunting? Yes. Impossible – no, based on how both ethanol and biodiesel production blossomed under similar tax credit benefits to meet a changing demand.
Sustainable aviation fuels is at a crossroads, and a healthy leg-up could be just the boost it needs to ramp up and provide an important environmental benefit for all of us at a much-needed time.
Emily Pickrell is a veteran energy reporter, with more than 12 years of experience covering everything from oil fields to industrial water policy to the latest on Mexican climate change laws. Emily has reported on energy issues from around the U.S., Mexico and the United Kingdom. Prior to journalism, Emily worked as a policy analyst for the U.S. Government Accountability Office and as an auditor for the international aid organization, CARE.
UH Energy is the University of Houston’s hub for energy education, research and technology incubation, working to shape the energy future and forge new business approaches in the energy industry.
