After COVID: A Lower Carbon Future for Commercial Aviation

December 12, 2020

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(Environmental and Energy Study Institute) Briefing Series: By Air, Land, and Sea: Navigating the Climate Future -- The Environmental and Energy Study Institute (EESI) held a briefing series on climate mitigation and adaptation in the transportation sector. The series covered ports, aviation, and public transit.

As commercial aviation recovers from the COVID-19 contraction, it will be critical to foster strategies and policy to help the industry reduce its climate impact. In this briefing, we examined two of these strategies—sustainable aviation fuels (SAF) and aircraft technology improvements. Rep. Julia Brownley (D-CA) delivered opening remarks. Chris Tindal of the Commercial Aviation Alternative Fuels Initiative (CAAFI) addressed the potential of low-carbon sustainable aviation fuels with life-cycle emissions substantially below conventional fossil-based jet fuel and the policy formula for scaling up the SAF industry. Barbara Esker of NASA’s Advanced Air Vehicles Program described NASA’s role in the development of new efficient engine and airframe technologies as well as gas-electric propulsion. WATCH VIDEO

HIGHLIGHTS

Rep. Julia Brownley (D-Calif.); Member, House Select Committee on the Climate Crisis; Member, House Transportation and Infrastructure Subcommittee on Aviation

Aviation-related emissions account for 2.6 percent of total U.S. greenhouse gas emissions and nine percent of U.S. transportation sector emissions.
The development of low-carbon technologies, such as electrification and fuel cells, is advancing quickly for surface transportation, but is just beginning in the aviation industry. In the near term, aviation will continue to be dependent on liquid fuels.
Sustainable aviation fuel (SAF) is a low-emission aviation fuel that can be blended with traditional jet fuel and used in existing aircraft engines. SAF has been certified by regulators as meeting safety requirements and has already been used in over 200,000 flights.
SAF can reduce aviation emissions by at least 50 percent compared to conventional fossil jet fuels.
Commercial-scale production of SAF is just beginning and needs a jumpstart from policy makers to meet the goals of the House Select Committee on the Climate Crisis’s staff blueprint for climate action.
Rep. Julia Brownley's newly introduced Sustainable Aviation Fuel Act (H.R. 8769) would address marketplace challenges and boost production by:
- Establishing a tax credit for sustainable aviation fuel that would increase based on the emissions reduction it achieves, so as to incentivize production of the most sustainable aviation fuels;
- Authorizing $1 billion of funding in competitive grants over five years for the production, transportation, blending, and storage of sustainable aviation fuel;
- Providing money for research that would help the industry further decarbonize and reach its zero-emission goal; and
- Elevating the California low-carbon fuel standard to the national level for the aviation industry.

Chris Tindal, Assistant Director and Business Team Lead, Commercial Aviation Alternative Fuels Initiative (CAAFI)

CAAFI is a public-private partnership that works to promote the development of non-petroleum, synthetic drop-in fuel production at a commercial scale across the supply chain from feedstocks to end users.
The commercial aviation industry has three basic goals: (1) to be more efficient at a rate of 1.5 percent annually, (2) to achieve carbon neutral , and (3) to emit 50 percent less carbon in 2050 compared to 2005. These reductions will come primarily from radical new technologies and sustainable aviation fuels (SAF).
SAF is a synthetic jet fuel which comes from many different biochemical and thermochemical processes. It uses sustainable feedstocks such as waste oils, fats, greases, sugars, purpose-grown oil seed crops, and municipal solid waste.
There are seven different production pathways approved by the American Society for Testing Materials (ASTM International), six more in the process of approval, and more than 15 in early development.
SAF is drop-in replacement fuel that can be mixed in with regular traditional aviation fuels. It is not an additive. Current production pathways have been approved up to a 50/50 blend.
There are two SAF facilities in operation in the United States, with the largest production at the World Energy plant in California, and two more under construction in Nevada and Oregon that will use municipal solid waste and wood waste as feed stocks.
Although production is small, there is high demand for SAF. Offtake commitments total $6.5 billion for 350 million gallons/year [in an offtake agreement, an airline agrees to purchase a share of the SAF production from a facility, often before that facility has been built. This guaranteed revenue stream facilitates construction].
By 2025, the SAF industry expects to produce over a billion gallons per year—about one percent of the total global consumption of jet fuels.
Several airlines have set themselves more ambitious emission reduction commitments. Some airlines, like SAS, Lufthansa, and Finnair, have provided an option for customers to pay slightly more to offset the additional cost of SAF.
Some European countries are setting SAF mandates for their commercial fleets.
There is significant demand for SAF, but several challenges still need to be addressed. The potential for acceleration is a function of engagement, offtake agreements, facility replication, and policy.

Barbara Esker, Deputy Director, Advanced Air Vehicles Program, National Aeronautics and Space Administration (NASA)

The U.S. aviation industry represents about $1.6 trillion in U.S. economic activity and provides 11 million direct and indirect jobs. U.S. carriers have transported 21 million tons of freight worldwide and carried more than 889 million passengers.
NASA analyses identified the three largest drivers for aviation innovation as demand for global mobility and transportation, sustainability and environmental challenges, and technology convergence. These are identified in NASA’s Strategic Implementation Plan, which includes a strategic thrust of developing technologies for ultra-efficient subsonic transports.
NASA takes technology through several levels of development, called technology readiness levels. These include basic research, concept formulation, laboratory validation, testing, and prototype demonstration. This framework illustrates the industry role to commercialize the technology and ensure a safe deployment in the fleet. Technology infusion into the fleet takes time.
NASA has identified four areas of primary technology interest to help enable the next generation of subsonic transports.
- Small-core gas turbines: Technological advancements are possible in the compressor and other core components. These advancements are directly related to the efficiency of the engine.
- Electrified aircraft propulsion: NASA is identifying where and how electric components can complement the propulsive efficiency of gas turbines. Advancements in this area will work in a hybrid fashion and do not mean 100 percent electrification for transport-class aircraft. There are potential efficiency gains from partial electrification, as well as potential maintenance benefits.
- Transonic truss-braced wings: Trusses support longer, thinner wings which are more efficient.
- High rate composites manufacturing: Composite air frames are lighter and can improve the overall efficiency of the aircraft. Currently, the rate of composite manufacturing is much lower than that of traditional metal manufacturing. Through advanced computation methods, measurement techniques, and knowledge of composite material systems, we have a goal of a four to six times manufacturing rate increase.
Complementary to the NASA program, the University Leadership Initiative engages universities and supports technological innovations in aviation.

Question & Answer Session

What are the key pieces of information that policymakers need to know and act on to support sustainable aviation fuel (SAF)? What policy actions would expand the production and use of SAF?

Tindal: We need a long-term, stable policy. One example is the California low-carbon fuel standard, which has given a lot of incentives to the market. We need a policy that incentivizes and levels the playing field between renewable diesel and SAF. Rep. Brownley’s SAF Act has the potential to help things move forward. READ MORE

Download Chris Tindal's Slides

Download Barbara Esker's Slides