In a quiet corner of a business park near Sheffield, a revolutionary project is taking place that could shape the future of aviation. Inside a research facility at Sheffield University’s Sustainable Fuels Innovation Centre (SAF-IC), researcher Ihab Ahmed is preparing to ignite a small jet engine, repurposed from its original use in a commercial airliner, to test new, sustainable fuels developed in an adjacent laboratory.
This facility, dedicated to the development and evaluation of synthetic aviation fuels on a small scale, represents a significant stride in the global push toward cleaner air travel. Sustainable aviation fuels (SAFs) are synthetic alternatives to conventional fossil fuels, produced from renewable sources like waste cooking oils, vegetable fats, agricultural waste, and captured carbon dioxide. Unlike fossil fuels, SAFs do not contribute additional carbon dioxide to the atmosphere, offering a promising solution to one of the aviation industry’s most pressing challenges: reducing its carbon footprint.
As Ahmed monitors the engine’s performance from a nearby control room, sensors provide real-time data, allowing for precise analysis of the exhaust gases. “From an environmental perspective, it’s day and night,” says Ahmed, emphasizing the potential of SAFs to achieve net-zero carbon emissions and reduce harmful particulates that affect air quality and contribute to contrail formation.
The aviation industry, which is expected to double its global fleet in the next two decades due to rising demand in emerging markets, faces a daunting challenge. The International Air Transport Association has set a target for airlines to reach net-zero emissions by 2050. While new aircraft models are 15-30% more fuel-efficient than their predecessors, the industry needs more than just newer planes to meet its climate goals.
Long-term solutions like hydrogen power and electric planes are in development but face significant technical and logistical hurdles. Hydrogen, while a potential clean fuel source, is difficult to store and requires substantial infrastructure for production and distribution. Similarly, current battery technology is too heavy for large aircraft and long-haul flights. As these technologies remain years away from viability, SAFs offer a near-term solution, capable of being used in today’s aircraft with minimal modifications.
However, the path to widespread SAF adoption is fraught with challenges. Currently, SAFs must be blended with traditional jet fuel, with regulations capping the SAF component at 50%. Despite modern aircraft being capable of running on 100% SAF, the supply is minimal—comprising just 0.05% of the EU’s aviation fuel—and the cost is prohibitively high, three to five times more than regular jet fuel.
Governments are stepping in to accelerate the adoption of SAFs. The UK has introduced a “SAF mandate,” requiring 2% of all jet fuel to be SAF by next year, with targets increasing to 22% by 2040. The EU has a more ambitious timeline, aiming for 63% SAF usage by 2050. In contrast, the US offers subsidies to lower the price of SAFs but has not set minimum usage requirements.
To meet these ambitious targets, production must scale up dramatically. SAFs can be made from a variety of sources, including biomass and even human waste. However, there are concerns about the environmental impact of some feedstocks, particularly if they lead to deforestation or compete with food production. Alternatively, the “power to liquid” method, which creates fuel from water and carbon dioxide using renewable electricity, holds promise but remains costly and requires significant advancements in renewable energy and carbon capture technologies.
Despite these challenges, the aviation industry is making strides. At the recent Farnborough Airshow, several major announcements highlighted the growing investment in SAF production. A consortium including Airbus, AirFrance-KLM, and Qantas announced a $200 million investment in mature SAF-producing technologies. Boeing also unveiled a partnership with Clear Sky to promote a British company’s innovative method of producing SAF from human waste.
These developments underscore the industry’s commitment to overcoming the technical and economic hurdles to SAF production. While the path ahead is challenging, the work being done at Sheffield University and other research centers around the world offers hope that the aviation industry can meet its climate goals, one innovative fuel at a time.
