How to decarbonize your ship - the business case for a shore power refit on a tanker

A crude oil tanker can cut emissions at berth, reduce FuelEU exposure, and prepare for future compliance pressure through shore power retrofits. How is that? FuelEU Maritime and related decarbonization rules are increasing the cost of fossil fuel use, while ports are gradually improving the business case for cleaner operations alongside the berth. For tankers, this creates both a challenge and an opportunity. Shore power offers a direct way to reduce onboard emissions during port stays, but applying it safely and economically to tanker operations is far from straightforward. This case study explores the business case for retrofitting a crude oil tanker to make use of Onshore Power Supply (OPS), using the Toril Knutsen as a reference vessel. It looks at the onboard retrofit requirements, expected auxiliary power demand at berth, CAPEX implications, safety constraints, regulatory drivers, and the electricity price at which shore power starts to make economic sense. Compared with many other ship types, tanker OPS retrofits are more complex due to hazardous cargo environments, ATEX-related safety requirements, cable handling challenges, and the difficulty of selecting a safe and practical connection location. These technical and operational constraints strongly influence both cost and feasibility. The study therefore focuses not just on whether shore power reduces emissions, but under what conditions it can realistically be implemented. The tool and case study show that the business case depends heavily on berth power demand, port stay duration, local electricity prices, retrofit complexity, and the degree to which FuelEU and other regulations reward reduced emissions at berth. While CAPEX can be significant, the long-term value improves where tankers call frequently at equipped terminals, where auxiliary loads are substantial, and where compliance costs continue to rise. Key assumptions include the vessel’s hoteling power demand profile, operational time at berth, retrofit scope, and the availability of compliant and competitively priced shore power infrastructure. Because tanker applications remain relatively rare, the study also highlights the wider standardization and infrastructure gaps that still need to be addressed. The result is not a one-size-fits-all answer, but a realistic and practical framework to assess when shore power retrofits for tankers are technically viable and economically worthwhile. As regulation tightens and ports continue to electrify, early insight into these conditions can help operators make better retrofit and compliance decisions. Find more information and use the tools here: https://www.sustainable-ships.org/sto...