Aviation on a Net-Zero Flight

The global aviation sector reached a major milestone in climate action in November 2023 when Virgin Atlantic’s Boeing 787 aircraft successfully completed a flight from London to New York entirely on 100% sustainable aviation fuel (SAF). Powered by Rolls Royce Trent 1000 engines, the aircraft used 60 tonnes of SAF for testing and the flight, proving that sustainable fuels could be just the answer to the sector’s dilemma due to rising emissions.

The aviation sector accounted for 2% of the global carbon emissions in 2022, according to the International Energy Agency. While this figure may not look  big, the imminent rise in greenhouse gas emissions in tandem with the projected increase in air travel in the coming years is worrisome. Already, the sector has surpassed other modes of transport, be it by rail, road or shipping, in terms of growth in recent decades. Globally, the demand for air travel is expected to double by 2040, according to International Air Transport Association(IATA). 

India stands third in the domestic aviation market in the world and is expected to overtake the UK to become the third-largest air passenger market in 2024, according to India Brand Equity Foundation. Its aviation market is expected to grow from an estimated $13.54 billion in 2024 to $23.24 billion in 2029 at a compound annual growth rate of 11.41%, according to Mordor Intelligence. 

Data from  the Ministry of Civil Aviation shows that the number of domestic passengers carried by the country’s airlines between January and September 2023 was 112.86 million, up from 87.42 million in the corresponding period in 2022, registering a growth of 29.1%. For the same period, the number of international passengers in 2023 was 45.99 million, an increase of 39.61% from the previous year’s 32.94 million. On November 19, 2023, airlines in India flew 4,56,910 domestic passengers, the highest single-day air traffic till then since the pandemic hit.  

While this growth is good news for the industry and the economy, it does not bode well for the country’s climate action goals. SAF could be the solution India needs to keep its aviation industry growth sustainable. In its strategy for net-zero emissions by 2050, IATA has highlighted that SAF will be responsible for 65% reduction of greenhouse gas emission. The rest will be accounted for by deployment of new technologies, infrastructure and carbon offsetting or carbon capture.  

The Case for SAF 

Sustainable aviation fuel is produced from biological sources. Major feedstock categories for production of SAF are sugar streams, waste and residue lipids, agriculture residue and municipal solid waste. In its Clean Skies for Tomorrow: Sustainable Aviation Fuels as a Pathway to Net-Zero Aviation report with McKinsey and Company, the World Economic Forum (WEF) notes that SAF can reduce climate impact by up to 60% and lifecycle emissions by 99%—in theory—and does not need any major changes to be done to aircraft or airport infrastructure. The report explains that while both SAF and fossil fuels have equivalent carbon dioxide emissions, the former recycles used carbon and introduces significantly reduced amount of additional carbon. On the other hand, burning fossil jet fuel introduces entirely fresh carbon in the atmosphere.  

India is a heavy consumer of aviation turbine fuel (ATF). Between April and November 2023, the provisional figure for production of ATF in India was 11.1 million metric tonnes, according to the Petroleum Planning and Analysis Cell (PPAC) of the petroleum ministry. WEF states that India has the potential to produce 30 billion litres per year of sustainable ethanol, which is used for producing SAF, from agricultural residue, solid waste and industrial off-gases. In May 2023, Union petroleum minister Hardeep Singh Puri had said that India had feedstock for potential production of 19 to 24 million tonnes of SAF per year, whereas the estimated maximum requirement of SAF in India, considering 50% blend, would be around 8 to 10 million tonnes per year by 2030. He had shared this data after the successful journey of India’s first commercial passenger flight using indigenously produced SAF-blended aviation turbine fuel.  

The PPAC reports that India crossed ethanol blending in petrol of 12% during the ethanol supply year of December 2022 to October 2023. In November last year, the petroleum ministry announced an initial indicative target of 1% SAF blending in aviation fuel in 2027 and 2% in 2028, both initially for international flights. The production and collaboration efforts for adopting sustainable aviation fuel are also in full swing. At the recently concluded Wings India 2024, Airbus and the CSIR-Indian Institute of Petroleum signed a memorandum of understanding to initiate SAF production.   

India has sent its homegrown SAF samples to United States Federal Aviation Administration Clearinghouse for ASTM D4054 qualification from ASTM International which develops standards for products and services globally. Once India receives the certification, it will be able to use this SAF for its commercial airlines. 

Anirban Mukherjee, managing director and partner, climate and sustainability head, Boston Consulting Group, says, “India has the potential to produce 45 to 55 million tonnes per annum of SAF from various waste streams, with low-cost renewable power offering export opportunities for Indian producers. Domestic SAF policies and aviation companies setting targets to use SAF will drive significant demand in India.”  

Salil Nath, general manager, Indian Subcontinent, Etihad Airways, says, “Airlines globally are undertaking a comprehensive and collaborative approach to integrate eco-friendly practices into their operations, marking a concerted effort towards a more sustainable and environmentally conscious future for air travel.” Nath calls for a balanced approach to growth. “Airlines can anticipate substantial long-term gains in operational efficiency through such initiatives. Adopting newer aircraft models will yield significant cost savings over time, effectively aligning economic interests with sustainability goals in the aviation sector,” he adds.

The Global Landscape 

In 2016, the International Civil Aviation Organization (ICAO) established the Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) framework with the primary objective of setting a carbon-neutral growth target with 2019 as the baseline. The implementation of CORSIA was divided into three phases: a pilot phase (2021–23), a first phase (2024–26) and a second phase (2027–35). Countries can opt out of the pilot or first phase. India will begin participating in the second phase in 2027.   

The WEF’s Clean Skies for Tomorrow report recognises the urgency of investment in and rapid scale-up of production and use of SAF. It observes that the integration of hydrogen and electricity in aircraft could significantly contribute to the industry’s net efficiency goals. However, it may be a decade or two before such aircraft take flight, and even those are likely to be smaller, shorter-range models. Using SAF is the most viable alternative. To increase its production, the sector must explore new technologies that can use less restricted feedstocks.  

Mukherjee says, “The three most viable SAF production pathways today are HEFA (Hydro-processed esters and fatty acids), alcohol-to-jet and G-FT (Gasification Fischer Tropsch). These employ used cooking oil and MSW (municipal solid waste) and agricultural residues like wheat or paddy straw as the primary raw material.” He notes that, unlike energy crops like jatropha, these sources do not directly hit agricultural production or cultivable land.  

Interestingly, the production of SAFs can also contribute to ending hunger and malnutrition. This involves promoting resilient agricultural practices, enhancing productivity, sustaining ecosystems and fortifying the capacity for adaptation to climate change, extreme weather events, drought, flooding and other disasters. However, this may necessitate increased investment, which will require enhanced international cooperation in rural infrastructure, agricultural research and technology development to bolster agricultural productivity, particularly in developing and least developed nations.   

Getting the Mix Right 

Besides SAFs, modern technology, infrastructure and aircraft will play an important role in emission reduction. The Ministry of Civil Aviation has initiated steps to achieve carbon neutrality and net-zero carbon emissions at airports nationwide. The process is being executed within an Indian carbon accounting and reporting framework. Airport operators with scheduled operations are encouraged to monitor the carbon emissions within their premises.  

Adopting SAF will help India achieve its net-zero emissions goal by 2070. However, India faces several challenges in the development of clean energy, says Mukherjee. As a heavily energy-dependent economy, India cannot cut down on the use of fuels. While SAF is a sustainable solution, it is costlier than ATF. Cost of production and procurement of SAF will remain the biggest concern for the aviation sector. The WEF report notes that SAF’s pricing currently is more than double that of conventional fuel, “but costs will decline with further innovations and efficiencies of scale as production increases.”

Making its own fuel is in sync with the government’s Make in India ambitions and will help it reduce its reliance on imports to meet fuel demands. Additionally, by reducing the carbon footprint of the sector, it will amplify the country’s pitch as a responsible partner in global climate action. The benefits more than make up for the cost concerns.