Clean Flying: Sustainable initiatives for green airport infrastructure

India’s aviation industry accounts for 2 to 3 per cent of the global carbon impact from em­issions. Carbon emissions from the in­dustry have increased by 32 per cent over the past few years. The Ministry of Civil Aviation (MoCA) recently announced that the net-zero targets of India can be streamlined by greening its airports and making them carbon-neutral. It has pushed the state governments to ensure that most of the operational brownfield airports and upcoming greenfield airports are carbon-neutral by 2030. MoCA has also advised the Airports Economic Regulatory Authority to reconsider the cost associated with green en­ergy use. Amongst the key sustainable initiatives, the Airports Authority of India has installed solar power plants at various airports, with a cumulative capacity of more than 54 MW-peak as of March 2023.

Carbon-neutral or net zero airport infrastructure essentially includes sustainable de­sign and construction practices and materials, along with circular resource management. The­re is an increased focus on recycled materials and using energy-efficient systems. These sustainable methods have a high initial capex, but the operational costs get minimised with the passage of time. Such methods also entail re­du­cing and optimising Scope 1, 2 and 3 emissions to decarbonise operations. Efficient reporting of greenhouse emissions by operators and developers is mandatory for Scope 1 and 2. Scope 3 emissions include all indirect emissions that are voluntarily reported by companies. Carbon disclosures, and environment, social and governance (ESG) reporting have, therefore, taken a big turn for private players in the sector.

Use of eco-friendly construction materials

Green and recycled construction materials are gradually entering the airport construction market as the sector adopts a sustainable appro­ach. Conventional construction materials are being replaced with industrial and construction by-products such as fly ash, plastic waste, recycled concrete aggregates, granulated blast furnace slag and fibreglass. With waste-to-wealth becoming a focus of the central government, newer ways to use recycled materials are being explored. To this end, the Kempegowda Inter­national Airport (KIA) in Bengaluru has used over 80 metric tonnes of plastic waste in road construction. A dry process has also been ad­opted by the contractors that involves the coating of aggregates with plastic waste. This allows better binding of bitumen with the plastic-waste coated aggregate, due to improved bonding and increased area of contact between polymer and bitumen. Moreover, the airport has made efficient use of bamboo, a natural material, for construction, further lowering carbon emissions. Through these initiatives, it has ac­hieved Level 3+ under the Airport Carbon Ac­creditation Programme of the Airport Council International (ACI).

Furthermore, it is estimated that 20 to 25 per cent of fly ash is being used in airport infrastructure. Although it takes a long time to gain strength after mixing, fixed concrete pavements made with this mixture have a lifespan of 30 years, with a need for recoating every six to seven years. Fibreglass, green steel and gr­een cement with lower carbon content are ot­h­er sustainable materials. A memorandum of un­derstanding was signed between Tata Steel Limited and Australia’s Broken Hill Proprietary Company Limited in July 2022 for the manufactur of green steel, to reduce the emission intensity of the blast furnace steel route. Th­rough this, both companies aim to use biomass as a source of energy in steel production, while applying carbon capture and utilisation strategies. Similarly, L&T Limited has introduced the use of fibreglass dowel bars in construction, which is also corrosion resistant and lightweight compared to steel bars.

Application of renewable energy

Indian airports with high sustainability ratings have harnessed green energy sources such as solar, hydro and wind energy. Energy optimisation through renewables immensely reduces the overall carbon footprint of airport infrastructure. Mumbai’s Chhatrapati Shivaji Maha­raj International Airport has achieved Level 4+, the highest level, under the ACI’s Airport Car­bon Accreditation Programme. It became one of India’s few 100 per cent sustainable airports by switching completely to green sources for its energy consumption needs. It was the first airport in India to introduce hybrid technology, which has been running on green energy since April 2022. The airport procures 5 per cent of its electricity requirement from on-site solar power generation, and the remaining 95 per cent from a mix of hydro and wind energy.

In a related development, the Indira Gandhi International Airport has also adopted green energy, having used only hydro and solar power for all its energy needs in June 2022. A long-term power purchase agreement has be­en signed by its operator, Delhi International Air­port Limited, with a Himachal Pradesh-based hydropower-producing company for the supply of hydroelectricity to the airport until 2036. It has set up a 7.84 MW solar power plant on the air-side, and an additional 5.3 MW rooftop solar power plant. This initiative will enable the airport to reduce indirect energy emissions by 0.2 million tonnes of carbon dioxide every year. Similarly, the Cochin Interna­tio­nal Airport is the first green airport in the world to be fully powered by solar energy. It led rene­wable energy adoption with the installation of its first solar photovoltaic power station on the rooftop of the arrival terminal.

Other sustainable initiatives

Circular on-site waste and water management is another key strategy adopted by airport deve­lopers and operators to lower their carbon footprint. The reuse and recycling of waste generated during airport construction are being integrated by contractors into their operations. For in­stance, Tata Steel Limited practices the reuse of scrap generated during the construction pro­cesses as part of its centralised system. This allows efficient tracking and monitoring of the entire waste chain. As a result, product manufacturing becomes more environment conscious. Similarly, Terminal 2 of KIA has tapped the potential of rainwater harvesting by creating ponds that can store 413 million litres, meeting the water requirement of the airport.

In another development, to optimise energy consumption with a smart solution, Schneider Electric has launched EcoStruxure, an end-to-end digital solution for the whole airport infrastructure value chain. This internet of things-en­abled platform allows airports to manage their energy requirement and enhance energy quality while meeting environmental standards. This, along with their Green Yodha initiative, bolsters the development of Airports 4.0, which will integrate sustainability with smart operations. LED-powered lighting is another energy-efficient technique that has been executed in KIA, which has the first runway in India to be fully lit with LED-powered lighting.

Carbon disclosures and reporting have also gained traction among private players. The Securities and Exchange Board of India propo­sed a regulatory framework for ESG disclosures to facilitate a balance between transparency, simplification and ease of doing business, in February 2023. It has additionally mandated the top 1,000 listed companies (by market capitalisation) to create filings as per the new Bu­siness Responsibility and Sustainability Reporting requirements, starting from 2022-23. This initiative will push airport owners to benchmark their sustainable initiatives, generating positive competition. More­over, the Scien­ce Based Targets initiative’s corporate net-zero standard is being promoted in the sector. It is the world’s first framework for corporate net zero target setting in line with climate science. To this end, Schneider Electric is helping in creating circularity in consultancy by providing environmental data points for ESG reporting th­ro­ugh an inbuilt software system. Additional tax saving through carbon disclosures gives companies in the sector further incentive.

Pushing limits

The central government aims to make 90 airports carbon-neutral by 2024, with several In­dian airports switching to green energy. Specific initiatives for the reduction of greenhouse gas emissions in the aviation space will be further explored by MoCA. These include the implementation of central air traffic flow management, flexible use of airspace, implementation of performance-based navigation and im­ple­mentation of continuous descent operatio­ns. It also organised knowledge-sharing sessions in March 2023 to standardise the carbon accounting and reporting framework of Indian airports, as well as raise awareness regarding climate change mitigation. Going forward, several sustainable technologies are expected to alter the airport development pattern, such as energy storage with fuel cells, microgrids, electrification and zero liquid discharge.