Net-Zero Airports

Airports are an integral part of the modern world, playing a significant role in offering faster transportation and shaping economies. But how many of us realise these large-scale, sophisticated transit hubs are mammoth energy consumers and significant contributors to carbon emissions? With the world grappling with the undesirable consequences of climate change, airports are in the spotlight, and there is a pressing need to transform them into greener, more sustainable options. Sustainability in design has become a crucial goal for airports worldwide. But can cutting emissions alone help meet this objective? Can airports truly go green and net zero? Let’s discuss it!

Sustainable airport design goes deeper than protecting airports from physical climate risks like extreme weather or rising sea levels. The move towards sustainability involves rethinking materials and green airport designs, embracing technology, managing waste, adopting circular economy principles, and re-evaluating airport scale.

In an online interaction organised by ACE Update, acclaimed architects and industry experts shared their expert insights on achieving sustainability in airports, including innovative material usage, intelligent water usage, and energy-efficient practices. They also evaluate the challenges and government regulations, both nationally and globally, catalysing the achievement of green and net-zero goals for airports.

Material innovation
Ar. Monalisha Sahoo, Managing Director, Ninth Dimensions, emphasises the need to embrace lightweight infrastructure in airport construction. “Lightweight infrastructure reduces both structural load and construction time. You don’t need bigger foundations, large infrastructure, or larger areas. Many components can be prefabricated and assembled on-site, both in the case of new airports and in expansions. Due to the reduced structural load, a lot of costs are saved. And, these structures are reusable and architecturally flexible.”, explains Monalisha.

Energy efficiency through HVAC systems and building envelopes
Juzer Kothari, managing director of Conserve Consultants, shares his insights on ensuring energy efficiency through proper HVAC designs. “Almost 50–55 percent of the total energy consumption of an airport goes into HVAC. This can be effectively mitigated by efficient handling of zoning, control systems, intelligent use of variable air volume systems, and VFD design for HVAC systems.”, elucidates Juzer.

Ar. Rinor Komoni, Principal and founder of Komoni Architecture explains how building envelopes can be designed to be energy-efficient for airports in humid regions. He says, “Reducing solar heat gain is key. We have to create more shading on the elevation. The glass should be leaning out with a cantilever roof to reduce direct sun, allowing only indirect light to enter. Properly insulating the roof, avoiding skylights, and using shading devices also help.”

Juzer also shares his insights on the “condensate recovery system” for reducing HVAC power consumption and “dual skylight design” for preventing glare, adopted by Conserve at Chhatrapati Shivaji Maharaj International Airport (T2), Mumbai, India.

Modularity is key!
Rinor shares his insights on how sustainability can be ascertained during terminal expansions. “Airports must be constructed considering futuristic usage. Ensure the airport size can accommodate at least 20 years without expansion. However, modularity is the answer to expansions with sustainability in mind. Having piers that are extendable by adding modules… Building modules on site, bringing them in, and attaching them to the end of the pier allows continuous growth. This gives much flexibility rather than building everything at once and waiting many years for it to fill before expanding with a new terminal.”, asserts Rinor.

“The module we choose must be tech-enabled and space functional. The solution could be a compact, tech-enabled smart airport, which, with the support of advanced technology, can serve not just 20 years but even 30 years. All infrastructure should be able to align with new technology, especially for operational requirements, because operational readiness is key.”, adds Monalisha.

How are governments catalysing the move towards green airports?
Juzer explains how the Carbon Credit Trading Scheme (CCTS) introduced by the Government of India will soon play a large role in the transition of airports to net zero. “Airports will soon come under this mandate. Like the PAT scheme, in place for Indian airports, the government will set a particular benchmark for carbon emission intensity for all airports.”, elucidates Juzer. He also shares his insights on GRIHA standards. “The second focus is on new airports. The Environmental Impact Assessment Committee has mandated that most new airports meet GRIHA or the LEED or IGBC Green Standards. And, certain areas of the project will need to achieve net-zero targets, either in terms of water or energy.”

Rinor shares his insights from a global perspective. “Abu Dhabi, UAE follows the Estidama rating system. For landscaping, the requirement is that you can only use 1 L water per sq.m per day. The government needs to focus specifically on airports and how we can develop a green system tailored just for them.”, says Rinor.

Challenges
“The major challenge is CapEx limitation. The difference between CapEx and design is always a challenge. Similarly, technology is not always well understood at lower or even strategic levels. It is mostly understood by the middle management only. Bridging this gap is a major challenge! Climate risks, stormwater management, and de-icing are also concerns. ”, outlines Monalisha.

Juzer outlines the specific challenges that came up with Mumbai T2, India’s first green airport. “Initially, we were commissioned to do a series of simulation studies, which was not popular then, for daylighting, internal lighting, glare, energy, etc. Also, the data that came out was not coherent with what the architects had visualised about the design. There was a lot of back and forth on what was right, simulation or design. And, there were no benchmarks.”, explains Juzer. “We followed the LEED daylighting and energy benchmarks and the ASHRAE 90.1 baseline benchmark. The initial challenge was that none of the benchmarks met the design, and vice versa.,” delineates Juzer.

The need for a collaborative approach
Airports must work with stakeholders, grounds, the energy sector and other industries to achieve sustainability goals. “It’s all interconnected—all integrated. The government wants the airport, the architects need to design, and the environmental engineers must ensure the lowest possible impact.”, opines Juzer. “I think it’s very important that all the stakeholders, including the contractor, are in the same room from the beginning.”, comments Rinor. “The business charter should serve as the guideline to understand the scope, vision, and mission required to achieve that vision, and everyone should be aligned with it.”, asserts Monalisha.

Airports achieving net zero through design and construction

1. Guadalajara International Airport Terminal 2, Mexico

• Design Approach: Developed by CallisonRTKL, this terminal integrates vernacular architectural elements with sustainable design.
• Sustainability Features: Emphasis on reducing embodied carbon through material selection and construction methods.
• Goal: To operate as a net-zero carbon terminal, focusing on construction and operational emissions.

2. San Francisco International Airport (SFO), USA

• Initiatives: SFO aims to be the world’s first airport to achieve zero net energy, zero net carbon emissions, and zero waste production.
• Strategies: Implementation of energy-efficient systems, waste reduction programs, and sustainable building materials.

3. Oslo Airport Expansion, Norway

• Design Excellence: The expansion achieved a BREEAM “Excellent” rating, marking it as one of the most sustainable airport terminals.
• Innovations: Use local timber, energy-efficient design, and a snow-based cooling system to reduce energy consumption.

4. Appleton International Airport, USA

• Sustainable Construction: The terminal, constructed in 2013, is LEED-certified and features a roof-mounted photovoltaic system, ground source heat pumps, and rainwater collection.
• Achievement: Recognised as the nation’s first airport terminal to achieve a net-zero energy designation.

5. Portland International Airport (PDX), USA

• Innovative Use of Timber: The new main terminal utilises locally sourced timber, making it the largest project.
• Community Engagement: Partnerships with regional Indigenous communities for sustainable timber sourcing.

6. Techo International Airport, Cambodia

• GreenSky Initiative: Aims to be one of the world’s greenest airports by integrating natural light, vertical gardens, and rooftop greenery.
• Renewable Energy: Plans to be powered almost entirely by an onsite solar farm.

7. Cochin International Airport (CIAL), India

• Pioneering Solar Power: 2015 CIAL became the world’s first fully solar-powered airport.
• Sustainable Infrastructure: Features a 50 MW photovoltaic power station and solar carports, significantly reducing its carbon footprint