Acsa: How decarbonising aviation can drive a sustainable future

By Riaaz Essack

As global air travel surges, the aviation sector finds itself at a pivotal crossroads. Aviation currently contributes roughly 3% of global carbon dioxide (CO₂) emissions, underscoring the urgency to address climate change. Stakeholders across the aviation value chain are racing to reduce carbon footprints, yet a truly comprehensive decarbonisation strategy must extend beyond the airport’s perimeter for meaningful societal change.

Currently, global CO₂ emissions exceed 37 billion metric tonnes annually, with South Africa ranked 11th in per capita emissions at 5.65 tonnes per person. This is primarily driven by the country’s reliance on coal for energy, which powers approximately 85% of our generation and transportation. The Paris Agreement’s 2030 targets call for reducing the global average CO₂ footprint to 2.3 tonnes per person, making South Africa’s energy transition a critical priority.

The shift is possible. South Africa can transition from coal to renewable energy sources, supported by frameworks such as the National Environmental Management Act (NEMA), which recognises the rights of people, but also emphasises economic development. Opportunities to tap alternate sources of local energy cannot be stopped by the sentiments of few. We must recognise the impact energy has on improving the quality of life and its job creation potential.

The US provides a compelling example—once heavily dependent on coal, it significantly reduced its carbon footprint to 2.76 tonnes per person within a decade by investing in shale gas, alternative energy sources, and federal incentives. This demonstrates that bold policy and innovation can drive meaningful environmental change.

The US federal government’s strategic involvement in technology set the stage for the shale gas revolution, and South Africa’s Hydrogen Roadmap (HySA), led by the Department of Science and Innovation (DSI), offers a similar approach. Airports Company South Africa (Acsa) is leveraging its partnership with DSI to utilise hydrogen technology without the prohibitive set-up costs associated with pilot and demonstration facilities.

Decarbonising aviation, however, involves more than aircraft design or alternative fuels - it requires a comprehensive approach to the entire lifecycle of aviation emissions. From infrastructure maintenance to passenger ground transportation, every aspect of air travel contributes to its carbon footprint. Airports, as hubs of transportation and commerce, are uniquely positioned to lead this transformation.

In 2023, Airports Council International (ACI) launched the “Airports of Tomorrow” initiative to address the energy, infrastructure, and financing needs of airports over the next few decades. In practical terms, it means that airports will migrate to renewable and/or cleaner energy and play the role of an energy hub. Beyond energy for its infrastructure, operations, and aircraft, airports will offer energy options to passengers and those that connect to its intermodal transport system.

With Airbus set to launch a hydrogen-powered commercial jet by 2035, airports must begin preparing for the impact. For Acsa, readiness goes beyond simply piloting hydrogen technologies to inform infrastructure design. While hydrogen-powered ground transport, fuel networks, and stationary fuel cells are already proven, the real challenge lies in adapting the airport’s operating model to accommodate a new energy source.

This transition demands a holistic approach that encompasses people, infrastructure, and regulation. The first priority is updating civil aviation regulations to ensure the safe integration of hydrogen at airports. This includes educating and engaging key stakeholders - airlines, regulators, airport tenants, local authorities, insurers, and staff - on the potential and safety of hydrogen technology. Additionally, the shift will require a re-evaluation of airport disaster management strategies, as hydrogen-powered aircraft and storage facilities will introduce new safety protocols.

On the infrastructure side, Acsa is already planning for the integration of hydrogen into its airport design. This includes identifying optimal locations for hydrogen and jet fuel facilities, implementing security measures, and ensuring emergency preparedness. Given the +30-year master-planning and bulk services timelines for airport development, these considerations must feature along with evolving passenger preferences and regulatory expectations.

A major challenge in this energy transition is mitigating the risks associated with new technology adoption. If hydrogen technology inception at airports is incorrectly timed and/or experiences major setbacks, the airport infrastructure development programme can be compromised. Acsa has, beyond own use, also positioned itself to produce, store, and distribute hydrogen. The airport being part of an intermodal transport solution reduces the set-up costs for hydrogen transport. Hydrogen delivery cost, driven by densification and transportation, can constitute as much as 35% of the landed cost. At O.R. Tambo International, leveraging the current jet fuel rail-siding will significantly reduce this cost. This approach reduces financial risk of abortive investment and provides flexibility in response to the evolving energy landscape.

Additionally, Acsa is investigating how hydrogen production can address local water scarcity issues, a critical challenge in South Africa. While desalination is often prioritised, reusing wastewater for hydrogen production offers an alternative solution. Airports generate wastewater, and ACSA’s investment in hydrogen production provides an opportunity for water reuse and freeing up water processing capacity at local municipalities.

Green hydrogen is attractive because it is created from water and uses a renewable source of energy. The recurring question, however, is: At what cost? Fortunately, there is no dominant design for hydrogen production outside of petrochemicals, where the choice is reforming. There are no less than half a dozen commercial routes to produce hydrogen with no CO₂ emission to atmosphere, with cost varying from $2/kg to $9.5/kg at 30-bar and 99% purity. If the commercialisation of cheaper electrolyser technology goes beyond 2030, the fall-back position is a low carbon source for hydrogen. This will also make a significant positive impact to decarbonisation.

While hydrogen is a promising fuel, Sustainable Aviation Fuels (SAFs), a drop-in fuel derived from renewable resources, is another opportunity to decarbonise aviation. At current US prices of around five times the price of jet A1, a 10% dilution will raise ticket prices by around 15%. The sentiment of South African passengers is that such cost must be absorbed by the airline. The adoption of SAFs cannot be the problem of the airline alone; it requires a competitive logistics from the producer to the aircraft, airports to play a role in aggregating demand so that producers can manufacture at economies of scale, and regulatory bodies that define realistic requirements. It’s only through collaboration across the aviation network that SAFs can scale to meet the sector’s needs.

Acsa is also exploring the potential of harnessing energy from airport waste. While many airports have basic recycling programmes, the next frontier lies in using anaerobic digestion to convert food waste, sewage, and sludge into biogas. This technology has proven effective in producing energy for heating and generating nutrient-rich fertiliser, further aligning airport operations with sustainability goals.

A hydrogen-powered airport with in-house waste management brings the opportunity to demonstrate urban living through micro-grids for balancing energy demand. Unlike coal and less for natural gas-based power, hydrogen power does not suffer from proximity to feedstock production for economies of scale. Electrolysers are modular, making deployment on an as-needed basis.

At O.R. Tambo International, we have some 1800 tenants that form the airport city. This gives the potential to also blueprint urban living in a community two times the size of phase one of Waterfall Estate in Midrand. The current airport’s activities of real estate management; facilities and vegetation management; fuel supply; utility demand management; security; and site management are analogous to activities to keep a suburb operational.

As we look ahead, aviation’s decarbonisation journey is not just about reducing emissions - it’s about transforming airports into sustainable, energy-efficient hubs that also support broader environmental, town planning, and economic objectives. Airports, particularly in emerging markets like South Africa, have the opportunity to lead this transformation, not only within the aviation sector but across the global infrastructure landscape.

Acsa’s vision extends beyond air travel. By integrating technologies and sustainability practices, we are positioning ourselves as a global partner in shaping the airports of tomorrow. We are not just contributing to the future of aviation - we’re contributing to the future of how we will live.

Riaaz Essack, Acting Lead Asset Management, Airports Company South Africa.

BUSINESS REPORT