New hydrogen hybrid IOPU sparks OEM interest.

Known as Project Coeus, the three-year project has seen Perkins partner with e-powertrain specialists Equipmake and Loughborough University’s Wolfson School of Mechanical, Electrical and Manufacturing Engineering, to develop an innovative, advanced fuel-configurable hybridised IOPU.

The four fuels selected for inclusion in Project Coeus – ethanol, methanol, bio-methane and hydrogen – have one characteristic in common: they are all spark-ignited fuels. To utilise these fuels Perkins has created a configurable spark-ignited combustion platform on which the project relies.

The project has developed a hybridised IOPU, to deliver a robust and trusted fuel-configurable plug and play solution ​that produces reliable performance and is designed to meet global emissions standards, ensuring flexibility for the user.

Based on the Perkins® 1200 Series platform, the 1206 hydrogen hybrid IOPU on display will deliver a total of 379 kW – made up from the engine and the integrated motor generator unit (MGU), which boosts performance – and 1938 Nm at 1200-1500 rpm. An advanced hybrid cooling system reduces fuel consumption and noise from the IOPU by utilising on-demand cooling technology.
 

What’s happened so far?

“Over the last year we’ve been running two variants of the hydrogen engine,” explained Ian, “a direct injection and a port-fuel (PFI) injection variant. We’ve learnt a lot from the initial testing work and we’re now starting to pull the whole system together for the next phase of the project.

“So, this week at CONEXPO-CON/AGG we’ve shown customers the full engine system, with the cooling system, and the MGU sitting at the back. This is our full hybrid power pack. It’s a drop-in power unit, using hydrogen power with hybrid assist to give customers diesel like performance from a hydrogen system.

”In terms of the performance of this hydrogen unit compared to the diesel variant, what we’ve found during the initial testing is that in terms of peak power we got pretty close to diesel on this hydrogen system, achieving 190 kW in this hydrogen engine compared to 225 kW in the diesel version, but then utilising the MGU, we can boost the performance even further to achieve 379 kW.

“The other difference is transient response. For hydrogen, we must manage the air flow through the engine more carefully, relying on the turbo performance. You can’t just throw fuel at the engine and get transient response, like you can with a diesel engine. To minimise this change, we are using the hybrid system which has instantaneous torque.”

Ian added that throughout the show customers had commented on the compactness of the power unit and benefits of its fuel configurability.

“It’s really all about optimising the system to deliver the power we need, for the right emissions level, with all the right systems efficiencies,” said Ian, pointing out additional changes the team have made to the unit.

“On the cooling pack we’ve made some changes. It’s not a conventional power unit cooling pack. We’ve separated some of the cooling systems to allow us to fan them differently. There’s an electric fan system on the charge cooling and a viscous drive fan unit on our main radiator that allows us to optimise fuel consumption, as we only use the fan when we need to. By understanding the duty cycles and the right operation, we can minimise fuel consumption and minimise noise. This is a big powerful power unit, and this cooling pack is neat, compact and fits in a very similar space to previous generations.”
 

What’s next?

“So far, we’ve tested the core engine work and some of the hybrid elements, but these have been done in isolation,” explained Ian. “Our next step is to test them together, so we’ll have the engine with the hybrid system on, on a test bed for the next few months.

“Then we’re going to build this whole power unit – the full system, the drop in with the cooling system, with the hydrogen engine, with the hybrid system, and the battery that comes with it, into a machine and test at our Peterborough, UK, facility by the end of the year. It’s one to watch.”

And you can be sure that Powernews will continue to bring you the latest developments throughout 2026.