Helping shipowners build their stairway to decarbonisation

Shipping is under tremendous pressure from regulators, investors, charterers and society to decarbonise and reach net-zero emissions by 2050. To accomplish this tectonic shift, shipowners will need to take practical steps now to transition from conventional marine fuels to carbon-neutral and zero-carbon fuels. This will mean banking on the commercial availability of future fuels like green ammonia or green hydrogen, even though they don’t exist today as marine fuels.

“Shipowners are indeed faced with a complex carbon risk picture,” DNV principal consultant for maritime environment advisory and principal author of the report Maritime Forecast to 2050, Linda Sigrid Hammer, tells Marine Propulsion. “Uncertainties are linked to the availability of green fuels, but also to the development of technologies to use these fuels and to the development of regulations and other drivers.”

In short, the road to decarbonisation has lots of twists and turns and isn’t well lit. Fortunately, shipowners can use DNV’s fifth edition of Maritime Forecast to 2050 as a signpost. The report sets out the ambitious goal of distilling a dozen decarbonisation scenarios to guide shipowners on potential paths to zero emissions by forecasting the availability, uptake and pricing of alternative fuels and green technologies.

DNV’s report uses a greenhouse gas (GHG) pathway model to forecast the fuel mix and the CO₂ emissions in the world fleet to 2050 under different decarbonisation scenarios.

“Our intention is to assist owners in identifying their own decarbonisation stairway – as we call it – to manage carbon risk. This decarbonisation stairway is a practical plan for how to stay under the required carbon projection trajectories,” says Ms Hammer. And, as she points out, shipowners will have to continually improve the performance of, and invest in, their ships to stay in compliance and remain commercially competitive.

“Shipowners are faced with a complex carbon-risk picture”

“Shipowners will need to gradually reduce the carbon intensity of their ships. Understanding the costs associated with the fuels and technologies needed to stay under the required carbon reduction trajectories is vital for them to stay competitive, as is knowing the technical design implications of the fuel choices they make to eliminate ‘showstoppers’ and reduce costs of potential conversions,” she says.

Ms Hammer says this will require factoring in fuel availability and basic measures at the newbuild stage to “accommodate for fuel flexibility … and to be prepared for several possible fuel transitions during the lifetime of the ship.” This will need to be factored into the planning of the 1,000 to 2,000 ships that are expected to be ordered annually up to 2030.

Using a techno-economic study for carbon-risk management can help in planning new ships, says Ms Hammer. This consists of two parts: the first is an assessment of the economic potential of the fuel and energy efficiency strategies over the lifetime of a ship meeting the carbon-reduction target trajectory; the second part is a structured review of the impact of the chosen fuel strategy on ship design. The results from this techno-economic study can be fed into the shipbuilding specification, and this framework is specifically designed to allow detailed assessments of fuel flexibility and fuel-ready solutions. Fuel-ready solutions indicate a ship that is prepared to be converted to a different fuel later in its lifetime. This means “planning for fuel flexibility and fuel-ready solutions that can ease the transition and minimise the risk of investing in stranded assets,” says Ms Hammer.