Considerations for marinas

Ultimately there is no one-size-fits-all solution to decarbonising recreational craft given their varied size, operational profiles, and geographical locations. There are however, an increasing number of options becoming available, leveraging key elements identified in other motorised sectors (both on-road and non-road mobile machinery, as well as commercial shipping, etc.), which can assist in reducing greenhouse gas emissions (GHG) from propulsion systems. Whilst some, such as sustainable or renewable fuels, are available today through select distribution channels, many new energy carriers or energy convertor technologies rely on projected advancements by 2035.

All this does not make it very easy for marina owners and operators to make strategic decisions and plan accordingly for the future demands of customers using alternative fuels - or the need to supply low-carbon energy carriers in line with local or national GHG mitigation regulations or incentive schemes.

Given the relatively high energy density of our current fossil fuels (petrol or gasoline for spark ignition engines and diesel for combustion ignition engines), many sustainable alternatives will need additional storage space both onboard the craft as well as within the marina, potentially requiring significant improvements in the distribution networks.

The summary below provides an overview of some of the potential benefits and drawbacks of alternative fuel supply:

Sustainable or renewable fuels

Examples of these include HVO (hydrotreated vegetable oil) fuel and e-gasoline/petrol, which is considered a carbon-neutral fuel. Whilst synthetic fuels are currently under development by some car manufacturing companies such as Audi, there are still challenges to the supply, distribution and pricing of these as competitive alternatives.

Fuel docks in marinas will be able to make use of the same storage and supply infrastructure used for current fossil fuels, but additional separate storage and equipment may be required for the period in which both fuels need to be available.

Full electric

Electricity can be supplied via the grid (with some network upgrades required), as well as generated from renewable sources (wind/solar) within the marina. Having a separate on-site energy storage system would reduce peak electricity loads and possibly reduce costs in the long term. Vessel to grid (V2G) technology is undergoing significant improvements with companies such as Volvo Penta conducting research studies to explore the potential of enabling hybrid and electric vessel batteries to support the electrical grid. Ultimately this will hopefully allow larger marinas to benefit further from those craft with low utilisation. Simultaneous high-power charging during peak periods may be difficult to achieve and levels of priority for certain users (short-term rental fleets) would need to be determined. 

Hybrid electric and hydrogen (fuel-cell)

Whilst the use of hybrid electric systems results in higher energy efficiency, lower fuel consumption, exhaust emissions, and maintenance costs for the vessels themselves, these types of independent vessels would not typically place extra demands on the marina and could reduce the levels of local pollutants.

Hydrogen (internal combustion engine)

Hydrogen can either be transported safely by tankers or trucks, supplied directly by pipeline, or produced sustainably on-site as ‘green’ hydrogen. Significant investment may be required by marinas depending on the options available.

ICOMIA and its Marine Engine Committee (IMEC) Members commissioned Ricardo Plc. to conduct independent scientific research together with life-cycle analysis (LCA) experts to identify suitable propulsion technologies for decarbonising recreational craft. This comprehensive study is available at www.propellingourfuture.com

ICOMIA Marina Group (IMG) Members have been participating within the PIANC (The World Association for Waterborne Transport Infrastructure) Working Group 217 providing guidance on The Impacts of Alternative Fuel Propulsion Systems for Recreational Vessels on Marina Design and Management (not yet published).

Methanol and ammonia should also be considered as alternative fuels for the next generation of superyachts, although this will be very much dependent on which pathways are chosen in terms of the commercial shipping sector.

Clearly the alternative energy landscape is set to change at a rapid pace and future technology may require a review of the options mentioned in this section. In terms of the infrastructure needed, there will always be a ‘chicken versus egg’ situation, (meaning the difficulty of sequencing actions where each seems to depend on others being done first) and readers are encouraged to engage with their national Marine Industry Association for further information.

A list of all ICOMIA Members can be found here:  https://www.icomia.org/icomia-members/