The panel - which was formed in February and consulted more than 120 representatives from 40 industry players over six months - said airport operations are highly energy intensive, and proposed six ways that Changi can reduce its footprint.
One is to replace the existing fleet of about 2,000 to 3,000 vehicles used for airside operations with cleaner alternatives, such as fully electric or hydrogen-powered vehicles.
About 10 per cent of Changi Airport's airside vehicles are already fully electric, and there are more than 100 charging points available across the four terminals.
For instance, baggage tractors at Terminal 4 now run on battery power.
For larger vehicles that are harder to convert, such as catering trucks, the panel mooted using renewable diesel made from animal fats, food waste and plant oils.
The panel also found that air-conditioning consumes the most electricity at Changi Airport, accounting for 60 per cent of the power used by the four terminals.
Work is being done to reduce this, including upgrading existing air-conditioning systems and using solar films on windows. But the panel said other solutions like district cooling can be adopted to make air-conditioning at the airport more efficient. Detailed assessments should be done over the next two years, including trials.
These alternative cooling methods can then be included in the design of the upcoming Terminal 5 to achieve maximum energy savings, the panel said.
Changi Airport should also maximise solar power use by looking at whether it can install solar panels on untapped open spaces within the airfield, the panel added.
The airport currently has rooftop solar panels that have a total capacity of 22 megawatt-peak - 4 per cent of Changi's pre-Covid-19 energy use.
Installing solar panels on water bodies and open areas surrounding the airport's runways could help meet an additional 5 per cent of its energy needs.
However, the report also flagged possible safety risks, including glare from the solar panels affecting air traffic controllers and pilots. Another issue is whether these solar panels can generate enough electricity to be commercially viable.
The Civil Aviation Authority of Singapore (CAAS) should conduct a technical assessment of this proposal, the panel said.
CAAS should also try to secure imported low-carbon electricity for the airport, and a study should be done to see if it is feasible to establish a facility that can convert waste material into fuel or electricity, the panel said.
On the air traffic management front, the panel said new technology and operating procedures can help to reduce unnecessary fuel burn and emissions by facilitating more direct flight routes, among other things.
These improvements could also benefit passengers by minimising delays.
The panel gave three recommendations it said could be implemented within the next four years, and a fourth that could come into play some time from 2027 to 2032.
The proposals include studies on ways to improve the reliability and timeliness of weather information provided to pilots and air traffic controllers.
For airlines, the panel gave five recommendations centred on promoting the adoption of sustainable aviation fuel and new aircraft technology.
One is the need for Changi Airport to develop a long-term secured supply ecosystem for sustainable aviation fuel, which has been touted as the most promising near-term solution to significantly reduce carbon emissions from planes.
It is produced from renewable raw materials, such as used cooking oil or animal fats, but costs three to five times more than conventional jet fuel.
Since July, Singapore Airlines and Scoot flights out of Changi Airport have started using a blend of regular jet fuel and sustainable aviation fuel in a one-year trial.
Carbon credits tied to the use of sustainable aviation fuel have also been sold as part of a pilot scheme.
