By Kevin Hobbs

SHIPPING produces 940 million tonnes of CO2, contributing to 2.5 per cent of greenhouse gases annually. This, combined with the UK Government’s Clean Maritime Plan and the Scottish Government’s ambition to be a net-zero emissions country by 2045 means the maritime industry has work to do. Every decision we make must be looked at through a net-zero, carbon footprint lens.

When seeking maritime solutions to the emissions and climate change challenge, there are many hurdles to overcome. This includes types of fuel, provenance and availability of electricity, cargo capacity requirements and, perhaps most importantly, cost. To reach net-zero in the stipulated timeframe, significant investment is required in the country’s infrastructure, as well as emerging technologies.

For powering larger vessels, LNG fuel is currently the best solution. It is a much cleaner energy source and provides a 25% reduction in carbon footprint. It almost entirely eliminates emissions such as nitrous oxide (NOx), sulphur oxide (SOx). It’s these emissions that are responsible for air pollution and can affect those with health conditions such as asthma.

In Scotland, we are lucky that a lot of our electricity is powered by clean, renewable energy. Pairing this with rapidly improving technology makes us hopeful that future vessels can use electricity as a power source. This would eliminate the carbon footprint completely, provided the electricity is sourced cleanly.

However, the feasibility of fully electric ferries will depend largely on the grid capacity of the islands they serve. Ferries will need to plug in and charge at each port, and if an island’s electrical capacity cannot support this without disrupting the energy supply to residents and businesses, then it’s a less feasible option. It will potentially require solid investment in the islands’ energy generation infrastructure or enhanced grid interconnectors.

When in “hotel load alongside”, that is, only using energy to power heating, lighting and other necessary facilities for the crew living onboard, ferries have traditionally burned hydrocarbon fuel for power. The installation of charging facilities on many vessels (including ferries) is becoming more common to allow them to plug into the main grid and use electricity while berthed. This is already a legal requirement for many types of ships in cities such as Miami or Los Angeles, where pollution legislation is in place to prevent overnight dockinig if they cannot plug into the main grid.

Consideration must also be given to the load capacity requirements of electric vessels. The weight of the battery, and the energy density within it, has a direct correlation to the dead weight of the ship. The cargo-carrying capacity will then be lower on board, and will dictate how many freight or passenger vehicles can be carried on each crossing.

There is no one-size-fits-all approach to addressing the challenges the maritime industry is facing. Simultaneous investment in infrastructure is vital if we are to eradicate our carbon footprint entirely. In the meantime, environmental considerations are being made in the design and build of all new vessels, and we will continue to adapt existing vessels in any way practical help on the journey to becoming a net-zero emissions country.

Kevin Hobbs is chief executive of Caledonian Maritime Assets Ltd (CMAL)