The power will be used by Welsh Water’s more than 4000 operational sites across the country. The water utility has taken this decision as part of its commitment to increase the use of renewables in its energy consumption.

Presently, Welsh produces about 20% of its energy through wind, hydro, solar and anaerobic digestion and plans to increase it to 30% by 2019.

Welsh Water is a not-for-profit organisation that supplies about 828 million litres of water every day to more than three million people, serving most of Wales, Herefordshire and parts of Deeside.

The contract with Dong Energy is a follow up of a loan agreement by Welsh Water with European Investment Bank (EIB) for £250m. With the loan, the company plans to invest on renewable energy generation programmes in the near future.

The loan is expected to enable Welsh Water, which has the highest credit rating in the UK’s utilities sector, to meet its£1.7bn investment programme between 2015-2020 to invest in its assets.  

Welsh Water energy head Mike Pedley said: "Our contract with DONG Energy secures green energy for the next five years whilst also offering good value for Welsh Water. As a not-for-profit company, every pound we can save on energy helps us keep bills down for customers.

“We are also looking forward to exploring how we can best utilise DONG Energy's flexibility services to drive further value from our operations."

DONG Energy UK sales business managing director Jeff Whittingham said: "Welsh Water are making fantastic progress in reducing their carbon footprint but, while generating as much energy in-house as they can, they still need to look to the market for the bulk of their needs.

"We are delighted they have chosen DONG Energy to supply green energy for their 4,300 sites over the next five years.

"As the global leader in offshore wind, we are well placed to deliver a bespoke service meeting their requirements. This contract represents significant growth of our power business which has continued to grow during the first half of 2017."

Image: Dong Energy to supply 100% green power to Welsh Water. Photo: Courtesy of DONG Energy (UK) Ltd.