Exeter Airport hydrogen ground equipment

A trial at Exeter Airport has generated new operational evidence for using hydrogen-powered ground equipment. The study, led by the airport, Cranfield University, and ULEMCo, tested a dual-fuel hydrogen-diesel ground power unit (GPU) over multiple winter days.

According to a new report from Cranfield University, the equipment performed safely and reliably. It delivered measurable reductions in diesel use and carbon emissions. Airport ground crews reported little practical difference between operating the converted equipment and a conventional diesel GPU.

Trial Operations and Results

The Winter Operations HyGPU project involved eight operational days. The equipment completed 15 tests lasting a total of almost six hours. It consumed 7.41kg of green hydrogen, displacing an estimated 24.23 litres of diesel. This avoided approximately 63.9kg of carbon dioxide emissions.

No safety incidents or significant operational problems were reported. The report estimates that converting all seven of Exeter Airport's existing GPUs to the same dual-fuel system could save more than 11,000 litres of diesel and roughly 35 tonnes of carbon dioxide equivalent annually.

Dr Thomas Budd, associate professor of airport decarbonisation at Cranfield University and author of the report, commented on the findings. "This trial has taken us another step beyond a one-off demonstration," he said. "The results show that the equipment can operate safely and deliver measurable reductions."

Performance in Winter Conditions

The report found no clear evidence that lower ambient temperatures directly affected the GPU's technical performance. Test temperatures ranged from 4°C to 14°C.

However, the findings indicate that periods of inactivity, including overnight cold starts, may delay the point at which the equipment begins using hydrogen. The dual-fuel unit starts on diesel and only introduces hydrogen after its engine reaches the required operating temperature. The report says longer trials would be needed to confirm the relationship between inactivity, temperature, and performance.

The findings suggest dual-fuel technology may offer the greatest benefit for airport equipment used continuously or for longer periods. Equipment used for short, intermittent tasks may be better suited to other zero-emission technologies.

Next Steps for Hydrogen at Airports

Stephen Wiltshire, Exeter Airport's managing director, linked the trial to earlier work. "The original Zero Carbon Turn project proved that different types of hydrogen-powered ground equipment could work together safely in a live airport environment," he stated. "This latest study delivers on our commitment to build on that by testing the technology over a longer period."

The latest report identifies three priorities for further research. These are longer trials as part of normal day-to-day airport operations, the development of higher-volume hydrogen storage and semi-permanent refuelling facilities, and scalable on-site testing of hydrogen fuel purity.

Dr Budd outlined the necessary progression. "The next stage must be to move from limited trials towards longer-term use as part of business-as-usual airport operations," he added. This project was developed in response to a prior Cranfield University report calling for hydrogen technology to be tested for longer periods and under a broader range of conditions.