The aviation industry is one of the fastest-growing and most influential sectors in the world. It contributes to the global economy, trade, tourism, and social development. However, it also has a significant environmental impact, as it is responsible for about 2.5% of global carbon dioxide (CO2) emissions and other greenhouse gases (GHGs) that contribute to climate change . Moreover, it consumes a large amount of non-renewable fossil fuels, which are becoming scarce and expensive. Therefore, there is a need for a paradigm shift in the aviation industry, towards more sustainable and eco-friendly practices. This is where the concept of green aviation comes in.
1. Definition of green aircraft
Green aircraft are aircraft that use less fuel, emit less pollutants, and have less noise than conventional aircraft. They are designed to minimize the environmental impact of aviation, while maintaining or improving the performance, safety, and comfort of air travel. Green aircraft can be achieved by using different strategies, such as:
- Improving aerodynamics: This means reducing the drag and weight of the aircraft, which reduces the fuel consumption and emissions. For example, using winglets, blended wing body, or laminar flow control .
- Using alternative fuels: This means replacing or blending the conventional jet fuel with more sustainable and cleaner fuels, such as biofuels, hydrogen, or electricity .
- Using advanced materials: This means using lighter, stronger, and more durable materials for the aircraft structure and components, such as composites, alloys, or nanomaterials .
- Using innovative propulsion systems: This means using more efficient and less noisy engines and propellers, such as turbofans, turboprops, or electric motors .
2. Eco-friendly technology in aviation
The aviation industry is constantly developing and adopting new technologies that aim to reduce the environmental impact of aviation and enhance the sustainability of air travel. Some of the latest eco-friendly technologies in the aviation industry are:
- Solar-powered aircraft: These are aircraft that use solar panels to generate electricity and power the propulsion system. They can fly without using any fuel and emit zero emissions. An example of a solar-powered aircraft is the Solar Impulse 2, which completed a round-the-world flight in 2016 .
-Electric aircraft: These are aircraft that use batteries or fuel cells to store and supply electricity and power the propulsion system. They can reduce the fuel consumption and emissions by up to 90%. An example of an electric aircraft is the Pipistrel Alpha Electro, which is the first certified electric trainer aircraft .
- Hybrid aircraft: These are aircraft that use a combination of different energy sources and propulsion systems, such as jet fuel, electricity, hydrogen, or biofuels. They can optimize the performance and efficiency of the aircraft and reduce the environmental impact. An example of a hybrid aircraft is the E-Fan X, which is a joint project by Airbus, Rolls-Royce, and Siemens to develop a hybrid-electric regional jet .
- Bio-inspired aircraft: These are aircraft that mimic the shapes, structures, and functions of natural organisms, such as birds, insects, or plants. They can improve the aerodynamics, stability, and adaptability of the aircraft and reduce the noise and emissions. An example of a bio-inspired aircraft is the Airbus A350 XWB, which has a wing design inspired by the albatross .
3. Renewable energy and aviation
Renewable energy is the energy that comes from natural and inexhaustible sources, such as solar, wind, hydro, geothermal, or biomass. Renewable energy can play a vital role in the transition to green aviation, as it can provide clean and sustainable electricity and fuels for the aviation industry. Some of the benefits of renewable energy for aviation are:
- Reducing the dependence on fossil fuels: Renewable energy can reduce the reliance on fossil fuels, which are finite, costly, and polluting. This can enhance the energy security and diversity of the aviation industry and reduce the vulnerability to price fluctuations and supply disruptions .
- Reducing the greenhouse gas emissions: Renewable energy can reduce the greenhouse gas emissions from the aviation industry, which are a major contributor to global warming and climate change. This can help the aviation industry meet its emission reduction targets and comply with the international agreements and regulations .
- Creating new opportunities and jobs: Renewable energy can create new opportunities and jobs for the aviation industry and the related sectors, such as manufacturing, installation, operation, and maintenance of renewable energy systems and infrastructure. This can boost the economic growth and social development of the aviation industry and the regions where it operates .
4. Challenges and solutions
Despite the potential and progress of green aviation, there are still many challenges and barriers that hinder its widespread adoption and implementation. Some of the main challenges and solutions for green aviation are:
- Technical challenges: Green aviation requires advanced and complex technologies that are still under development and testing, such as alternative fuels, electric propulsion, or bio-inspired design. These technologies need to be proven to be reliable, safe, and cost-effective, and to meet the performance and regulatory standards of the aviation industry .
- Economic challenges: Green aviation requires significant investments and incentives to develop, deploy, and scale up the green technologies and infrastructure, such as renewable energy systems, charging stations, or fueling facilities. These investments and incentives need to be supported by the governments, the industry, and the consumers, and to be balanced with the benefits and returns of green aviation .
- Social challenges: Green aviation requires a change in the behavior and attitude of the stakeholders and the public, such as the airlines, the passengers, the regulators, or the media. These stakeholders and the public need to be aware, educated, and motivated about the benefits and opportunities of green aviation, and to overcome the resistance and skepticism that may arise from the unfamiliarity and uncertainty of green aviation .
5. Impact on the environment
The impact of aviation on the environment is measured by various indicators, such as the fuel consumption, the CO2 emissions, the noise levels, or the land use. These indicators can be used to compare the environmental performance of conventional aviation and green aviation. According to a study by the International Civil Aviation Organization (ICAO), the global aviation industry consumed about 330 million tonnes of fuel and emitted about 1 billion tonnes of CO2 in 2019 . The same study projected that by 2050, the global aviation industry could consume about 500 million tonnes of fuel and emit about 1.5 billion tonnes of CO2, if no mitigation measures are taken . However, the same study also estimated that by 2050, the global aviation industry could reduce its fuel consumption by up to 40% and its CO2 emissions by up to 50%, if green aviation technologies and practices are implemented . Moreover, green aviation can also reduce the noise levels and the land use of the aviation industry, which can improve the quality of life and the biodiversity of the surrounding communities and ecosystems .
6. Laws and policies
Laws and policies are the rules and regulations that govern the activities and operations of the aviation industry. Laws and policies can have a significant influence on the development and adoption of green aviation, as they can set the standards, targets, and incentives for the environmental performance and sustainability of the aviation industry. Some of the current laws and policies that encourage green aviation are:
-The Paris Agreement: This is an international treaty that aims to limit the global temperature rise to well below 2°C above pre-industrial levels, and to pursue efforts to limit it to 1.5°C. The Paris Agreement requires all parties to submit their nationally determined contributions (NDCs), which are the plans and actions to reduce their greenhouse gas emissions and adapt to the impacts of climate change . The aviation industry is expected to contribute to the achievement of the NDCs and the Paris Agreement goals, by implementing green aviation measures and technologies .
- The Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA): This is a global market-based measure that aims to offset the growth of CO2 emissions from international flights above 2020 levels, by requiring airlines to purchase emission units from projects that reduce emissions in other sectors . CORSIA is expected to complement the green aviation technologies and practices, by providing a flexible and cost-effective mechanism to achieve the emission reduction goals of the aviation industry .
- The Clean Sky 2: This is a European public-private partnership that aims to develop and demonstrate innovative technologies that can reduce the environmental impact of aviation by 20-30% by 2035 . Clean Sky 2 involves more than 600 partners from the industry, research, and academia, and covers various aspects of green aviation, such as airframe, engines, systems, and operations .
7. Case studies
There are many examples of successful and inspiring initiatives and projects that showcase the potential and progress of green aviation. Some of the case studies of green aviation are:
- The Wright Electric: This is a US-based start-up that aims to develop and commercialize a 186-seat electric aircraft that can fly up to 300 miles on a single charge . The Wright Electric has partnered with EasyJet, a low-cost airline, to launch the electric aircraft by 2030, and to offer zero-emission flights between London and Amsterdam, one of the busiest routes in Europe .
- The Velis Electro: This is a two-seater electric aircraft that was developed by Pipistrel, a Slovenian aircraft manufacturer, and certified by the European Union Aviation Safety Agency (EASA) in 2020 . The Velis Electro is the first electric aircraft to receive a type certificate from EASA, and it can fly for up to an hour with a 30-minute reserve . The Velis Electro is intended to be used for pilot training, as it offers lower operating costs, less noise, and less maintenance than conventional aircraft .
- The SAF+ Consortium: This is a Canadian consortium that aims to produce and supply sustainable aviation fuel (SAF) from CO2 captured from industrial sources, such as cement plants or refineries . The SAF+ Consortium uses a technology called Fischer-Tropsch synthesis, which converts CO2 and hydrogen into synthetic kerosene, a drop-in fuel that can be blended with conventional jet fuel . The SAF+ Consortium plans to build a demonstration plant in Montreal by 2024, and to produce enough SAF to fuel 550 flights per year .
8. The future
The future of green aviation is bright and promising, as it offers many benefits and opportunities for the aviation industry and the society at large. The future of green aviation is expected to be shaped by the following trends and developments:
-The increasing demand for air travel: The demand for air travel is projected to grow by 4.6% per year until 2039, reaching 8.2 billion passengers by then . This will create a need for more efficient and sustainable aircraft and operations, as well as more innovative and competitive solutions for the aviation industry .
- The advancement of technology: The technology for green aviation is constantly evolving and improving, as new discoveries and innovations are made in the fields of renewable energy, materials science, artificial intelligence, and biotechnology. These technologies will enable the development of more advanced and diverse green aircraft and systems, such as supersonic, hypersonic, or suborbital aircraft, or air taxis and drones .
- The alignment of policies and regulations: The policies and regulations for green aviation are becoming more aligned and harmonized, as the international organizations and authorities, such as ICAO, EASA, or the International Air Transport Association (IATA), are working together to set common standards, goals, and measures for the environmental performance and sustainability of the aviation industry .
- The awareness and engagement of the stakeholders and the public: The stakeholders and the public are becoming more aware and engaged in the green aviation movement, as they are informed and educated about the benefits and opportunities of green aviation, and as they are involved and consulted in the decision-making and implementation processes of the green aviation initiatives and projects .
Conclusion
Green aviation is the concept and practice of reducing the environmental impact of aviation, while maintaining or improving the performance, safety, and comfort of air travel. Green aviation can be achieved by using various strategies, such as improving aerodynamics, using alternative fuels, using advanced materials, or using innovative propulsion systems. Green aviation can provide many benefits and opportunities for the aviation industry and the society at large, such as reducing the greenhouse gas emissions, enhancing the energy security and diversity, creating new opportunities and jobs, improving the quality of life and the biodiversity, and meeting the international agreements and regulations. Green aviation is also facing many challenges and barriers, such as technical, economic, and social challenges, which can be overcome by developing and adopting new technologies, investing and incentivizing green aviation, and changing the behavior and attitude of the stakeholders and the public. Green aviation is a promising and exciting field that is constantly developing and progressing, as it is driven by the increasing demand for air travel, the advancement of technology, the alignment of policies and regulations, and the awareness and engagement of the stakeholders and the public. Green aviation is the journey to the green sky, where the aviation industry and the environment can coexist and thrive in harmony.