Story ID: 
A New Start – with SAF 
By: lvalladares@ainonline.com
Caption: The future of medium-to-long-haul flight still needs the gas turbine but it also requires a new level of environmental performance. 
Word Count: 891
The future of medium-to-long-haul flight still needs the gas turbine but it also requires a new level of environmental performance. Sustainable Aviation Fuel offers a solution, and Rolls-Royce has started tests that will lay the groundwork for this transition to cleaner skies.As our world continues to combat the COVID-19 pandemic and looks with anticipation to the prospect of new vaccines to aid that fight, our thoughts also turn to a future where we can connect and be with each other again.
How we do that is the subject of some debate within the aviation industry and among the wider public, because people will want to travel, but do so sustainably. It’s an issue that was already at the forefront pre-COVID-19 and will undoubtedly return again post-COVID-19 as people return to new normality with even greater recognition of just how fragile and interconnected our planet is.
One element of that debate is the role of the gas turbine. While aviation continues to research new power solutions such as electrification and hydrogen it is clear that, for medium-to-long-distance travel, the gas turbine is the only viable solution for many years to come.
That is why the introduction of Sustainable Aviation Fuel (SAF) is now at the center of debate about the future of flying. It offers the prospect of breaking the carbon chain to reconcile the need to travel with the need for sustainability. The net CO2 lifecycle emissions of unblended SAF in this test are at least 75 percent less than conventional jet fuel, and as methods of production advance, there is the possibility of further reductions in years to come.
New tests
That is why the new ground tests we are carrying out on a Rolls-Royce engine demonstrator using 100 percent SAF for the first time are so important.
They aim to confirm that unblended SAF makes a significant contribution to improving the environmental performance of gas turbine engines. At present SAF is only certified for blends of up to 50 percent – so a change to allow 100 percent SAF would be groundbreaking in terms of sustainability.
The tests, in Derby, UK, have just started on a Trent 1000 engine which also incorporates ALECSys (Advanced Low Emissions Combustion System) lean-burn technology.
Paul Stein, Rolls-Royce Chief Technology Officer, said: “Aviation is a tremendous force for good, keeping the world connected, but we have to do that sustainably. If SAF production can be scaled up – and aviation needs 500 million tonnes a year by 2050 – we can make a huge contribution for our planet.
“We know that is a huge undertaking and will require teamwork right across a number of stakeholders, including aviation, the fuel industry, and government bodies. These tests are a contribution to the SAF debate, aiming to demonstrate that our current engines can operate with 100 per cent SAF as a full ‘drop-in’ option, laying the groundwork for moving such fuels towards certification.”
The SAF being used in the tests was produced by low-carbon fuel specialist World Energy in Paramount, California, sourced by Shell Aviation and delivered by SkyNRG. Fuel deliveries have taken place throughout November and the first engine run took place on November 24.
Confirming operability
The tests will run until the New Year and aim to confirm full engine operability with the fuel and will also monitor performance and emissions.
ALECSys is part of the UltraFan® next-generation engine demonstrator program, which offers a 25 percent fuel saving over the first generation of Trent engines. The ALECSys program is supported by the European Union via Clean Sky and in the UK by the Aerospace Technology Institute (ATI) and Innovate UK; the 100 percent SAF testing program is additionally supported by ATI, iUK and Gulf Aviation.
Gene Gebolys, Chief Executive Officer and founder, World Energy, said: “World Energy exists to empower leaders to innovate by providing the world’s most advanced low carbon fuels. Rolls-Royce is putting their technological prowess to work to understand how to maximize their potential in engines and we are proud to support them.”
Theye Veen, Managing Director, SkyNRG, added: “This program is a great example of what can be achieved when companies from across the aviation value chain that share an ambition of reducing emissions work together. As a pioneer in SAF, SkyNRG encourages innovative tests like this run by Rolls-Royce.”
In addition to supplying the SAF with SkyNRG, Shell Aviation is also providing Rolls-Royce with AeroShell lubricants for the ALECSys engine test program.
Anna Mascolo, President, Shell Aviation, commented: “For over 100 years, Rolls-Royce and Shell have worked together to drive aviation’s progress. This collaboration brings us one step closer to decarbonizing aviation. As well as the SAF, Shell Aviation will provide offsets using nature-based solutions to make the test net-zero emissions, reinforcing how multiple measures are essential if aviation is to achieve net-zero carbon dioxide emissions.”
Testing is due to be completed in December and results from the test are expected early in the New Year. In 2021 we also plan to expand our 100 percent SAF test program into business aviation - using a member of our state-of-the-art Pearl engine family, which powers Bombardier’s Global 5500 and 6500 and the Gulfstream’s new flagship G700.