This is the first of two posts on green aviation, covering the latest trends and innovations that are making aerospace more sustainable. Read Part 2 here.
What Is Green Aviation?
NASA, one of the biggest champions of green aviation, defines it as the pursuit of reductions in noise, greenhouse gas emissions and fuel usage in the field of aviation. While you may not have heard of the term, the aerospace industry spends $15 billion every year on sustainability and efficiency-related research and development, so green aviation is a huge driver in how the industry operates. The following are some of the most exciting innovations contributing to a greener future for aerospace.
Fuel efficiency has long been a key motivator for aerospace engineers. In the past, these pursuits were mostly to reduce fuel costs. Today, those same engineers are continuing to find new methods of achieving fuel efficiency, but with the health of the earth in mind.
The Boeing ecoDemonstrator: A Green Aviation Laboratory in the Sky
One of the most ambitious efficiency efforts today is Boeing’s ecoDemonstrator program. It is basically a flying R&D laboratory for exploring every kind of efficiency-increasing technology, with a focus on determining which technologies are feasible for large-scale adoption.
Since 2011, the ecoDemonstrator program has introduced over 60 technologies. Now in its fifth iteration, the most recent ecoDemonstrator aircraft was created for FedEx, which operated the plane in revenue service over the 2017 holiday season, testing out 35 new technologies that range from clear air-turbulence detection to ground-collision avoidance, as well as using 100% biofuel to vastly reduce emissions.
Some of the technologies tested in previous versions of the ecoDemonstrator program are:
- A ceramic engine nozzle designed to operate at a higher temperature, improving fuel efficiency while decreasing emissions and noise.
- Aircraft recycling – lightweight, highly recyclable building materials. In 2015, partnering with the Aircraft Fleet Recycling Association, Boeing was able to reuse or recycle about 90% of the ecoDemonstrator airplane (compared to the average of closer to 80%).
- A paint formulated to reduce icing and the accumulation of dirt and bugs, increasing aerodynamics and decreasing the need for aircraft washing.
NASA X-Planes Contribute to Green Aviation Technology
Another program addressing green aviation issues is almost as old as commercial aviation itself. NASA’s X-plane program began its history by achieving the first supersonic flight, and has gone on to pioneer many advanced aerospace technologies that have been adopted by the military, commercial aircraft engineers and U.S. space programs. Recently, however, NASA has shifted its focus to addressing some of the more terrestrial concerns associated with flight, namely the aforementioned green aviation goals. Recent X-plane designs have attempted to set new standards for fuel efficiency and noise reduction, as well as testing the limits of what is possible with biofuels and hybrid-electric and all-electric aircraft. After going to the moon, you’d think this would be a cinch, but if NASA is putting its brains behind it, it just goes to show you that green aviation is not only a vitally important issue, but also a really tough nut to crack!
Achieving fuel efficiency through design innovations has its limits. While new materials and processes are always being tested, the engines and wings of modern aircraft have reached near-peak levels of efficiency, meaning that any significant increases need to come from somewhere else. This is where alternative fuels can provide a boost. (Considering that airlines spend more than 25% of their operating expenses on fuel, it’s surprising that alternative fuels haven’t been adopted on a wider scale.)
While there is R&D being done to explore all-electric and hybrid-electric aircraft, electric commercial aircraft are unlikely before 2040, which means that sustainable aviation fuels (SAF) are the only feasible near-term solution to meeting industry sustainability goals. But even without the possibility of hybrid airplanes, the industry can seriously clean up its act. A recent NASA study showed a 70% reduction in particle emissions from jet engines powered with a 50–50 blend of biofuel and standard aviation fuel.
Fleet-scale implementation may still be a ways off, but there have been a number of SAF success stories in the past few years:
- In March 2016, United Airlines began using SAF on all daily flights between LAX and San Francisco, becoming the first airline to introduce alternative fuels in normal business operations. The change has increased fuel efficiency and reduced greenhouse gas emissions by up to 85% without any alterations to the aircraft.
- Alaska Airlines flew a test flight in November 2016 using a renewable biofuel comprised of forest residuals: limbs, stumps and branches left over after a timber harvest.
- One of the early adopters of alternative fuels, Virgin Atlantic pledged in 2016 to transition 10% of its fleet to an ethanol-based fuel developed by Boeing and made from steel mill waste. In July 2018, Virgin Atlantic and production partner LanzaTech got one step closer to creating the world’s first large-scale alcohol-to-jet (ATJ) facility to produce commercial quantities of fuel, securing a development grant from the UK government for the project.
- As of November 2017, 100,000 commercial flights have been completed using SAF.
More Sustainable Solutions for the Aviation Industry
Fuel efficiency and alternative fuels are two of the most important aspects of green aviation, but there are many other areas that are being explored to achieve sustainable solutions to the aviation industry’s large carbon footprint. We will discuss many of those in part 2 of this series.