Lloyd’s Register (LR) and the University Maritime Advisory Services (UMAS) have published their latest assessment of the current and future fuels available to shipping to help define the optimum solutions as the maritime industry seeks to reduce greenhouse gas emissions.

Building on research already undertaken by LR and UMAS into Zero-Emission Vessels (ZEVs) and potential transition pathways to decarbonization, the report examines three important elements of zero-carbon fuels when compared with traditional fossil-based fuels:

1. Estimates of the economic viability (investment readiness) of zero-carbon-fueled ships when compared with a reference ship using Low Sulfur Heavy Fuel Oil (LSHFO).

2. The technology feasibility (technology readiness) of the vessel and bunkering technologies needed to support zero-carbon-fueled ships.

3. The community readiness of zero-carbon fuels from the perspectives of lifecycle emissions and how the energy landscape is evolving in other sectors and what this means to the decarbonization of the shipping sector.

The authors derived an overall interconnected system of fuels and technologies that each form viable routes to ZEVs. They screened and analyzed downstream components of this system, including bunkering, storage, processing and conversion of the new fuels, to derive a Technology Readiness Level (TRL) for the current state of the technology, and an assessment of the outstanding barriers to achieving full deployment into the maritime fleets.

The economic case for ZEVs is mainly driven by the relevant energy/fuel price and how this evolves through the 2020s and 2030s to 2050. … This evolution over time means that different zero-carbon fuel options are more competitive in different decades and there is not one option which is the most competitive from today through to 2050.

In the short term, biofuels look marginally more competitive than fuels derived from renewable electricity or from natural gas with carbon capture and storage (NG with CCS). However, there are significant challenges related to the sustainability and availability of biofuels. Therefore, in the mid-long term, any biofuel pathway is uncompetitive and prone to restrictions or higher prices resulting from supply constraints and does not necessarily lead onto more resilient options such as hydrogen or ammonia derived from NG or renewable electricity.

For example, ammonia produced from hydrogen, where the hydrogen is produced from NG with CCS, can be considered to be comparable to biofuels in the short term and becomes the lowest cost zero-carbon option out to the 2050s. Furthermore, over time, the production and supply of ammonia can transition from NG to hydrogen produced from renewable energy, providing a more resilient long-term transition pathway.

Although certain pathways look more resilient than others from the perspective of asset longevity, fuel price is the predominant factor that impacts the total cost of operation (TCO). In anticipation of the impacts of the evolution of the global energy demands, and the associated uncertainty of biofuels being available and sustainable, a fuel which can be produced from NG or renewable electricity may offer longer-term advantages that are not seen in the very short term.

—“Techno-economic assessment of zero-carbon fuels”

The study illustrates that regardless of which zero-carbon fuels emerge as favored options from an economic perspective, from an onboard technology perspective, ZEVs are likely to be technologically possible in the next few years.

TRL rankings for ZEV technologies, from “Techno-economic assessment of zero-carbon fuels”.

From a technology readiness perspective, methanol, liquefied natural gas (LNG) and diesel are more mature than hydrogen and ammonia as rules and regulations currently exist and there are vessels already using these fuels. From an onboard technology perspective, there is minimal difference, for example, between using bio-methanol, e-methanol or NG-methanol; the same applies to LNG (bio-LNG, fossil-LNG and e-LNG).

One of the important barriers for new fuels such as ammonia and hydrogen is the storage and bunkering infrastructure. This means regulatory actors (Class and Flag) need to collaborate with original equipment manufacturers (OEMs) to enable the uptake.

—“Techno-economic assessment of zero-carbon fuels”

Upstream, operational and net CO₂ emissions for each fuel, from “Techno-economic assessment of zero-carbon fuels”.

However, for owners and operators to be confident around future investments, the industry will require confidence in the wider community around the fuel supply chain, both in terms of the availability in the quantities required and the land-based infrastructure for production, supply and distribution.