Making shipping sustainable and safe (part 2)

Posted on May 15, 2020
Making shipping sustainable and safe (part 2)

Our work to make ships clean and green continues! We are pleased to be starting work on another project with Marine South East to work towards zero emissions in the marine environment. In the FLO-MAR project, we will investigate the design and operation of vessel types most suitable for flow batteries. Alongside Swanbarton and Marine South East will be Houlder Ltd who designed the Victoria of Wight hybrid ferry, which operates between Portsmouth and the Isle of Wight, and Lloyds Register the provider of classification, compliance and consultancy services to the marine and offshore industry.  The project is supported by a grant from MarRI-UK under their Clean Maritime Call.  

The need for clean shipping

Ships are one of the world’s most polluting forms of transport because they depend almost entirely on heavy fuel oil and diesel fuel, which have high CO2 and particulates emissions. The need to reduce emissions from ships is a central goal of the UK’s Clean Maritime Plan to have zero-emission vessels operating in UK waters. Replacing fossil fuel propulsion by electrification is the most likely way to achieve this for most vessel types.

Outside the marine sector, there is considerable interest in electrical energy storage in general, but this is now typically focussed on either stationary applications connected to the electricity networks (grid storage) or electric vehicles (cars, buses etc). Many of these systems use lithium-ion technology, but we think there are other options which could be better suited to some types of ships. Interest in all-electric and hybrid vessels has surged over the past 12 months, which means it is now the right time to study some alternatives.

The FLO-MAR consortium believes that flow batteries are an attractive storage technology for some ships and boats, as for example:

  • The electrolyte tanks can be located anywhere in the hull of the vessel. The electrolyte is non-volatile and presents no fire hazard if stored below decks.
  • The battery’s power rating and energy storage capacity are independent: one is determined by the size of the electrochemical cell stack, and the other by the electrolyte volume. This makes the technology easily scalable across a range of vessel sizes and duty cycles.

There are many flow battery manufacturers in the stationary market focusing initially on large systems for bulk energy management, offering economies of scale. To de-carbonise the marine sector, vessel owners may be unsure which technologies they should be investing in, and what will be the operational and economic implications for their business. This project will help them choose and provide information on the technical advantages of flow batteries in terms of performance, operation, recharging/refuelling and infrastructure.