Powering Small Craft with a Novel Ammonia Engine

The small-craft (Sub-IMO) industry has traditionally used "marinized" engines for propulsion for a wide variety of craft, including leisure, commercial and fishing vessels. A large proportion of these are diesel engines which are based on automotive engines that are no longer in development as manufacturers move to electric or hydrogen propulsion.

This is creating supply issues for diesel engines in the short term, which will only get worse in the medium term. It is also driving manufacturers to install larger, heaver and proportionally more polluting engines into their vessels. This is creating a driver for the small-craft industry to move away from diesel to cleaner fuels, bit this is not supported by the level of R&D that it previously enjoyed.

Whilst pure electrical power may provide a viable solution to the automotive market, the mass of batteries and overall power requirements for the small craft market mean that pure electrical propulsion is less feasible for small, faster sea-going craft. Other alternative fuels do not have a sufficient energy-density to be stored on small craft, where weight and internal storage volume are critical. This is creating a significant problem for small-craft manufacturers, who currently have little other choice in fuel or propulsion technology -- especially if they want to move to clean technology.

In the longer term (with a suitable supply infrastructure) ammonia will provide a more feasible energy source for internal combustion engines as a dedicated power source linked to the propulsor or to power a generator in a hybrid system to charge batteries and extend range.

This project will create a novel, compact, lightweight but powerful internal combustion engine which is optimised to run on ammonia. The engine will feature novel technology to address come of the known issues with ammonia fuel. The size, weight and power output will be suitable for small craft.

In addition, work will be undertaken to assess the impact of the engine on potential performance for an example end-user, including range and speed to quantify any operational impact.

These results will be used to inform a complete Life-Cycle Assessment to determine the overall impact of the installation and use of both fuels in a representative small-craft. All the information and data gathered will then be used to create an assessment of the technical and economic feasibility of ammonia engines in small craft, informing the route to commercialisation.