Stevens adds hydrogen-on-demand units after successful trial

Stevens Equipment Rental has added Ultimate Cell hydrogen-on-demand units to its hire offering after a nine-month trial on two machines in its fleet.

It tested the technology on a 35-tonne Volvo EC350E excavator and an 18-tonne loading shovel, using OEM telematics to track fuel consumption. The programme ran for three months to establish a baseline, followed by six months after installation to measure any change.

Stevens Equipment Rental said the excavator delivered consistent fuel savings during the monitored period, with peak reductions of more than 25%. Based on 2,000 annual operating hours, it estimated users could save thousands of litres of diesel and cut carbon dioxide emissions by more than 10 tonnes a year.

The loading shovel also recorded lower fuel use over the six-month period, with savings of more than 10% in some cases compared with a conventional machine working in the same conditions.

The findings come as plant hire companies and contractors look for ways to reduce fuel bills and emissions from diesel machinery, which remains central to earthmoving and infrastructure work. Battery-electric and full-hydrogen alternatives are still limited in heavy equipment, particularly on remote sites where charging and refuelling infrastructure can be difficult to provide.

Customers can now specify the technology when hiring machines from the Stevens Equipment Rental fleet, particularly for projects with environmental, social and governance requirements. The move turns the trial into a commercial option for contractors seeking lower reported emissions without replacing equipment.

Trial data

Fuel savings were validated against real-world duty cycles using OEM telematics, according to Stevens Equipment Rental. The results were normalised to reflect variations in workload, idle time and operating conditions, which is significant in a sector where fuel burn can vary widely with terrain, operator behaviour, application and utilisation.

That caveat matters because fleet operators often scrutinise fuel-saving claims for aftermarket engine products. Stevens Equipment Rental said the trial was designed around controlled field conditions rather than a workshop test, and stressed that outcomes will vary between machines and jobs.

Operators involved in the trial also reported changes in how the machines felt in use. They noted stronger torque, smoother operation and quieter engine behaviour on both the excavator and the loading shovel, the company said.

How it works

Ultimate Cell's system is fitted as a retrofit rather than a full engine replacement. Stevens Equipment Rental said the unit draws a low electrical current from the engine battery to split an electrolyte fluid into hydrogen and oxygen, which are then introduced into the engine air intake in small amounts.

According to the company, the gases act as a combustion catalyst, helping the engine burn diesel more completely. It said this can increase torque from the same volume of fuel while reducing soot, and may gradually remove some existing carbon deposits inside the engine over time.

Stevens Equipment Rental described the installation as non-invasive and said it does not require additional operator training. The units can also be removed if equipment is returned to original manufacturer condition or transferred to another machine in the fleet.

Maintenance is limited to replacing the electrolyte at extended service intervals, and the process takes only a few minutes, the company said.

Commercial rollout

The adoption of the technology reflects wider pressure on plant hire groups to offer machines that can support contractors' carbon reporting on major projects while keeping diesel fleets in use. For many operators, replacing large earthmoving equipment before the end of its useful life is uneconomic, making retrofit approaches more attractive if savings can be verified.

Mark Need outlined that position in comments on the trial. "We are taking a pragmatic approach to decarbonisation," said Mark Need, Sales Manager for Scotland and the North of England at Stevens Equipment Rental. "While the industry waits for large-scale electric or full-hydrogen solutions to become commercially viable for heavy earthmoving - especially in remote locations - this trial proves our customers can use Ultimate Cell to reduce their impact today. It strengthens sustainability proposals for contractors tendering for major infrastructure projects."

For Ultimate Cell, the Stevens Equipment Rental programme provides a fleet-based reference case in a market where buyers typically want evidence from live site conditions rather than laboratory data. The supplier's UK business said the customer had taken a detailed approach to checking the numbers and machine performance.

"The SER team went into the trial with an open mind and a genuine appetite for innovation. They worked supportively with us to optimise the set-up with fortnightly check-ins at the start and a commitment to double-checking every result. SER can now confidently offer a solution that is largely invisible to the operator, but highly visible on the balance sheet and the sustainability report. By combining structured data analysis with real operational feedback, we've demonstrated that combustion optimisation can deliver measurable fuel and emissions reductions today, without waiting for future infrastructure or fleet replacement," said Gareth Eeson, Managing Director at Ultimate Cell UK.