The airline industry: often a second thought when thinking about our contribution to global pollution. Though, given the scope of this particular mode of transportation, it’s actually no surprise that these giant mechanisms, as well as the supporting operations, utilize a significant amount of fossil fuels. As a direct result, researchers are developing state-of-the-art technologies to eliminate carbon emissions from the aviation industry, from biofuels to hydrogen fuel cells. Green Development LLC, a sustainable energy provider in Rhode Island, explains the impact of current airline operations on our environment and how evolving renewable energy technologies can be expected to change the aviation landscape.
The Extent of the Problem
While only 2.4% of global carbon dioxide emissions come from aviation, mile for mile, flying contributes the most pollution when compared to any other form of transportation. Flying is more appealing and affordable for consumers, which means that carbon dioxide contributions will continue to increase unless the industry is able to easily transition to alternative fuel sources—up to 3.5% by 2030.
It’s not just the planes; airports—particularly large international airports—generate large quantities of pollution. Between lighting, heating, and cooling, charging stations, and more, 10-15% of an airport’s budget goes to energy. On average, airports use 19.7 kilowatt-hours (kWh) of electricity and 34.7 thousand Btu of natural gas per square foot annually—almost half of which goes to lighting and cooling. The latter adds to the pollution problem by emitting hydrofluorocarbons, greenhouse gases that have high global warming potential.
Potential Sources of Aviation Biofuels
Biofuels—fuels made from plants, algae, or animal waste–were actually first tested in flight at London’s Heathrow airport in 2008, utilizing biofuel created from a combination of babassu nuts and coconuts.
The goal is to find a source of biofuel that is easy to grow in a variety of climates and has a neutral, if not positive, benefit on its surrounding ecosystem. Dwarf saltwort is a succulent capable of thriving even in the coastal deserts of Abu Dhabi; growing in its brackish water, the plant is not only a source of biofuel, but it also has a symbiotic relationship with shrimp and tilapia, which can then be harvested for food.
Researchers are also working towards recycling outputs from human activity and turning them into sources of energy. One possibility is a fermentation process that uses industrial gasses from steel mills to create jet fuel. This process effectively recycles the carbon that is already being produced from industrial sectors and is capable of capturing one-third of the carbon from steel facilities that would otherwise end up in the atmosphere. Municipal waste is another potential candidate; this works by burning combustibles—particularly paper, cardboard, food waste, grass clippings, leaves, wood, and leather products—and using the heat produced to create steam to generate electricity.
With an energy-density-per-unit mass that is three times higher than traditional jet fuel, hydrogen is a top contender for creating zero-emission aircraft. The California-based start-up ZeroAvia has already successfully tested a six-seater aircraft powered by hydrogen.
The most prevalent process of producing hydrogen involves using natural gas, one of the biggest sources of carbon dioxide emissions. This type of hydrogen, referred to as blue hydrogen, utilizes traditional hydrogen production techniques—optionally using a capture and storage component—in which some of the carbon dioxide produced is captured and stored underground to reduce emissions.
A more environmentally-friendly approach is the production of green hydrogen, using water electrolysis to extract hydrogen. Still, the electrolyzer technology is expensive, despite being powered by renewable energy sources such as wind and solar farms. As green energy becomes more popular, the economies of scale could change: the cheaper the electricity, the more affordable the entire operation is to run on a carbon-free diet.
Successful Attempts and Plans for the Future
Boeing, one of the largest aircraft manufacturers in the U.S., has taken the lead in sustainable aviation. Not only was it among those that called on U.K. and E.U. governments to require a minimum quantity of sustainable aviation fuel to be blended into traditional jet fuel by 2025, but the manufacturing giant also announced that it would begin producing commercial aircraft that can fly 100% on sustainable aviation biofuels by 2030.
Melbourne Airport, Australia’s second-largest airport, constructed a solar farm capable of powering all four of its passenger terminals, equivalent to approximately 15% of the airport’s total energy consumption. The solar farm took just six months to complete and is expected to deliver significant annualized energy cost savings.
Bristol Airport in the U.K. currently runs on 100% renewables—a combination of solar panels and air source heat pumps provided by a renewable energy supplier. The airport intends to be completely carbon neutral by 2025 and net-zero by 2050.
About Green Development LLC
Green Development LLC is the leading developer of utility-scale renewable energy projects in Rhode Island, specializing in wind, solar, and battery storage. The company delivers significant energy savings to municipalities, quasi-public entities, nonprofits, and other qualified entities through the virtual net metering program while providing long-term lease payments to landowners and farmers.