Mahle Powertrain to develop sustainable and practical retrofit propulsion systems

A project led by Mahle Powertrain – carried out in collaboration with the Royal National Lifeboat Institution (RNLI), the University of Nottingham and Clean Air Power – is set to work on the development of sustainable propulsion systems for retrofit to powerful vessels where battery or other electrified technologies may not be suitable.

Initially, the project will target search and rescue vessels, such as those used by the RNLI. Due to the low energy density and weight of some currently available battery solutions and the requirements for a fast turnaround time between operations, Mahle states that such vessels need an alternative, yet sustainable propulsion system.

To meet these requirements, the project will use Mahle’s Jet Ignition (MJI) technology which has been optimized for hydrogen combustion and named HyJet. The HyJet system enables the ignition of sustainable fuels in clean combustion engines, with the project aiming to deliver this solution as a retrofit at scale for a range of sectors including commercial, professional and governmental.

MJI consists of a small pre-chamber which can be fitted into the cylinder head of an engine. Combustion is then initiated in the pre-chamber, with the hot combustion gases being forced through small gaps into the main combustion chamber as a series of jets which efficiently ignite the remaining mixture. The technology ensures clean and efficient combustion throughout the main chamber with minimal or no pollutants (such as nitrogen oxides) being emitted, even when running on lean hydrogen mixtures or other sustainable fuels.

“The current and predicted future state of battery technology alone can’t offer the range and performance required by the RNLI at an acceptable weight for retrofit to its lifeboats,” explains Martin Berger, vice president corporate research and advanced engineering at Mahle.

“The RNLI has committed to eliminating or reducing impacts on the environment, and to become a low-carbon, climate-resilient organization,” said Victoria Limbrick, carbon & energy manager, RNLI. “Fuel for our lifeboats, rescue watercraft and logistics vehicles accounts for around 57% of our total energy use. The HyJet project offers an exciting opportunity to investigate and learn about potential solutions that could help meet our challenging sustainability targets and fulfil our ambition to move away from fossil fuels.”

The project will start by analyzing usage data collected from the RNLI’s vessels during real-world operations to establish the fleet’s requirements in addition to identifying the best approach for clean operation. The consortium will also take into consideration the issue of onboard fuel storage and refuelling, a major consideration for emergency vessels. Vessel safety standards and regulatory compliance will also be assessed.

For the project, Clean Air Power will provide the fuel injection system, while the University of Nottingham’s Powertrain Research Centre will be responsible for fuel storage assessment and testing. Hybrid Marine Power will act as a consultant, in addition to providing legislative impact analysis.

The project – funded by the Department for Transport as part of the Clean Maritime Demonstration Competition – is the start to a follow-on project which aims to build a real-world demonstrator vessel.