The 630MW development, 20km off the southeast English coast, generated 369GWh in December, well above the 317GWh it generated in November, which was the previous monthly best for an offshore wind farm.

Net overall output for the year was 2.5 terawatt hours — enough to meet the needs of more than 600,000 homes.

The 175 Siemens 3.6MW turbines ran at a capacity factor of almost 79% last month, in wind speeds averaging 11.9metres