Portsmouth International Port recently switched on the UK's first high-voltage, multi-berth shore power system, allowing ships to plug into grid electricity and turn off their onboard generators while docked. In principle, that should reduce emissions and fuel costs, and the port aims to become a net-zero facility that also improves local air quality.
The problem, according to a report in Electrek, is that UK electricity prices have turned the usual economics of electrification upside down. Electricity accounts for roughly 80–85% of the total cost a vessel pays to use shore power, with port charges making up the rest. On top of that, Portsmouth faces an estimated 10% year-on-year rise in Transmission Network Use of System charges over the next five years.
Those numbers matter because the UK's House of Commons Library found electricity prices were 18% above the EU average in the second half of 2025, and the International Energy Agency reports that EU industrial electricity prices are more than double those in the US. The article contrasts this with the US, where rapidly expanding wind and solar capacity makes electrification a more attractive clean-air and cost-saving option. For now, the gap between environmental ambition and operating cost at Portsmouth suggests shore power's success depends less on the technology than on electricity policy.