ULEMCo, has reduced CO2 emissions for Aberdeen City Council through the deployment of road sweepers.

The optimised sweeper with hydrogen dual-fuel operation for both the powertrain and the “donkey” engine was announced in 2020 and has shown daily diesel displacement rates nearing 50%.

Since the start of 2022, the vehicle has been operating in Aberdeen, saving the annual equivalent of approximately 3 tonnes of CO2 emissions.

ULEMCo said applied to the whole fleet of sweepers, would lead to almost 30 tonnes of CO2 being eliminated from the operation.

The sweeper has been converted by ULEMCo to run on dual fuel, which allows a controlled quantity of hydrogen to be burned directly in the engine in combination with the diesel.

ULEMCo said this leads to exhaust emission reductions that relate directly to the proportion of the displaced diesel - typically between 20-40% depending on the duty cycle.

However, in this case, the duty cycle, engine types and operation are delivering as much as 50% of the energy from hydrogen.

In a year, each sweeper would use 700kg of hydrogen, so the nine-strong fleet would use 6.3 tonnes of hydrogen with the kind of regular supplies the council is accessing at the Aberdeen Hydrogen hub.

Extrapolating that to all the 333 UK councils would suggest that a saving of 10,000 tonnes is possible if an average of just 10 vehicles were converted at each.

ULEMCo said that this application and others like it such as refuse collection vehicles, gritters and other specialist equipment - are ideally suited to the use of hydrogen as their duty cycles take them back to base daily, enabling consolidation of scaled demand for hydrogen and the related refuelling infrastructure.

Amanda Lyne, managing director at ULEMCo, said: “A lot of attention and public funding support is focussed on looking for zero-emission solutions, but we cannot afford to wait for these to be commercially available, we must start transitioning to carbon-free energy using the full toolkit to achieve CO2 reduction immediately.”

Councillor Jenny Laing, leader of Aberdeen City Council, said: “I would say to local authorities that are thinking about moving to hydrogen technology, that it not only helps you with the economic targets that you may have, but it will certainly help with the environmental targets that each and every local authority in Scotland has set themselves.”