Good Energy has signed a deal to buy 12 per cent of the wind power produced at one of Dong Energy's offshore farms.
The Aim-listed, UK-based renewable electricity supplier will source wind power from the Danish energy group's 210 megawatt Westermost Rough farm off the Yorkshire coast for an undisclosed amount.
The energy provided will be enough to power more than 26,000 average homes.
The initial agreement is for one year, but that and the volume purchased are both likely to be extended as part of the wider cooperation between the two companies, Good Energy said.
Shares in Good Energy, which also reported almost a 40 per cent jump in core profit for 2016, rose about two per cent in afternoon trading.
Juliet Davenport, founder and chief executive of Good Energy, said the agreement will help the firm meet increasing demand for 100 per cent renewable electricity as its customer base grows.
"Offshore wind is a huge British success story and so we’re pleased to be playing our part by buying power from Westermost Rough."
Dong Energy is the UK's largest offshore wind operator, and this deal marks the first time a British supplier will buy electricity directly from one of its wind farms.
The Danish firm announced last year it is working to exit the oil and gas businesses completely to focus on wind power.
Soren Scherfig, head of trading and portfolio management at Dong Energy, said the company is working to support the energy transformation in the UK with a goal to become one of the UK's leading energy suppliers.
"We want to supply sustainable, reliable and affordable energy to our customers," Scherfig said.
Dong has also announced today an agreement with Britain's Banks Renewables to distribute onshore wind in the UK.