As the UK and the transport sector acts towards decarbonisation, there are increasing interest in the use of alternative fuels, both drop-in fuels (also known as alternative diesel fuels) or low/zero carbon fuels, such as LNG, methanol, hydrogen or ammonia.
The PLA is aware that fuel requirements and regulatory changes may be required and is preparing for this change, we have published a statement to set out what we are doing and how to bring new alternative fuels onto the river in the meantime.
A transition to alternative marine fuel and a corresponding propulsion system is crucial to meet the international and national regulations and emissions reduction targets. There is a wide range of potential alternative fuels currently being considered by the maritime sector as options to enable the transitioning to decarbonise the inland and international shipping. The alternative fuels that are most prominent as the transition or long-term future fuels for the maritime sector include biodiesels, LNG, LPG, methanol, hydrogen, ammonia, and technologies including batteries, fuel cell system, and wind-assisted propulsion.
The future trend and forecast of alternative fuels can be found from public sector research, such as Maritime Forecast to 2050 report by DNV, The Potential of Zero-Carbon Bunker Fuels in Developing Countries by the World Bank, Clean Maritime plan: Maritime 2050 environment route map from the Department for Transport and Maritime and Coastguard Agency. Below is a brief summary of the different alternative marine fuels.
Biodiesel and GTL (Gas-to-Liquid), can often be used as “drop-ins” with no or minimal changes to the vessels or bunkering infrastructure to accommodate these fuels, have been recognised to be the most feasible alternative fuels in the near term (now-2025) for inland operation. In general, biodiesel and GTL have lower air emissions than traditional diesel with biodiesel have an additional benefit of zero net carbon emissions in its life cycle. Biodiesels are a technically viable solution for domestic and international shipping. However, the volume of biodiesels required to supply the shipping sector are large, which might lead to a supply chain issue and cost. Find out more about drop-ins alternative fuels trial undertaken by the PLA.
Battery-electric allows zero tailpipe emissions and has been identified as a suitable near-term alternative solution for inland vessels. Many fully electric inland and international vessels are in operation or development worldwide, with inland battery electric vessels in operation since 2014. However, due to the efficiency and flexibility, the applicability of battery-electric is limited for seagoing vessels.
Liquid Petroleum Gas (LPG) and Liquefied Natural Gas (LNG) can both offer a significant reduction in air pollutants and slightly lower carbon emissions depending on the feedstock and the production. There is the potential for carbon savings from LNG to be outweighed by the release of unburned methane, a gas that has 25-30 times the greenhouse gas effect of CO2. The internal combustion engines can be modified to run of LPG or LNG, however, the relatively low energy density compared with traditional fuels would reduce the cargo/passenger capacity.
Fuel cell technologies, commonly runs on hydrogen or ammonia, also enable zero tailpipe emissions. The technologies are under development and have a number of pilot projects running globally. It is considered as a viable technological option for both inland and shipping. There are different feedstocks and ways to produce hydrogen. Hydrogen produced using renewable energy will have a significantly lower carbon footprint than those produced from fossil fuels.
An overview of what alternative fuels and technologies are suitable for the inland vessels on the Thames can be found within the Emission Reduction Report; for domestic and international vessels, information is available on the DNV website and on-demand webinars and IMO website and on-demand webinars.
Based on the current demands, international, national, and local policies and regulations, the PLA commissioned Royal HaskoningDHV and UMAS worked to develop a model of future fuels and geographic spread of demand and supply to help the PLA and our stakeholders to make decisions on the investment in innovative technologies. Find out more about the Future Energy Demand and Opportunities.
The technologies supporting decarbonisation in the maritime sector is evolving rapidly, the information presented here is based on information available at the time of writing.
Page updated 9/2/2022