Presentation at the Third IMO GHG Intersessional working group - The costs of GHG reduction in international shipping (IMarEST ISWG-GHG 3-3)
Dr Tristan Smith and Katharine Palmer presented the findings from the submission ISWG-GHG 3-3. The key findings include:
- Improving energy efficiency for a given size and type of ship is ultimately limited by the laws of physics. Thus, energy efficiency measures on their own are not enough.
- The price of zero-emission fuels would dominate the cost of decarbonization of international shipping. Table 1 shows various initiatives undertaken by the private sector, including shipowners and operators.
- Depending on how prices evolve for renewable electricity in coming decades, 100% absolute reduction of shipping GHG by 2050 appears achievable for a marginal abatement cost of $100 to 500 US$/t.
- Whilst hydrogen is well known as a potential future marine fuel, ammonia is less known and an interesting result was that for certain ship types, ammonia appears to outperform hydrogen in terms of profitability (figure 2).
- Conclusion: After initial increases in abatement cost, the cost curve reaches a "plateau" at a value which represents the carbon price needed to make zero-emissions technologies competitive with conventional propulsion.