Portsmouth shore power: cleaner ships, but higher bills than onboard generators

Portsmouth International Port launched the UK's first high-voltage, multi-berth shore power system, letting docked ships switch off generators and run on grid electricity. But with UK power prices 18% above the EU average, electricity makes up 80–85% of a vessel's bill, so plugging in can cost more than burning fuel onboard.

• Electricity accounts for 80–85% of a shore power bill, port charges for 15–20%
• UK electricity prices were 18% above the EU average in H2 2025
• UK transmission network charges are set to rise about 10% a year for five years
• The system cuts emissions and fuel use but does not guarantee savings