Northumbrian Water is to power all 1,858 of its sites using renewable electricity for the next four years.

From April 1 2018, a new green electricity deal will cover everything from the company's largest treatment works down to its smallest telemetry systems.

The agreement with Danish energy supplier Ørsted is one of the biggest contracts the water company has ever awarded.

Northumbrian Water is currently the only water company in the UK to use 100% of its sewage sludge to create energy, through Advanced Anaerobic Digestion, at its treatment works in Howdon, on Tyneside.

At Bran Sands, on Teesside, the company has also installed a 931-panel solar array on the roof, and in addition, it is home to England's largest hydro plant at Kielder Water.

Ørsted supplies renewable electricity from nine offshore wind farms in the UK, with the energy backed by Renewable Energy Guarantees of Origin (REGOs). This means Northumbrian Water can achieve 125,000 tonnes of CO2 savings each year.

Northumbrian Water's commercial director, Graham Southall, said:

"Energy is an essential part of our business and our contract with Ørsted has enabled us to significantly reduce our carbon footprint, as well as driving down costs."

Philip Carvel, category manager added:

"At Northumbrian Water, we want to work with forward thinking, responsible supply partners whose values match our own. Ørsted is a market leader in green energy solutions and has a remarkable vision for a more sustainable world.

"Combining this with a highly competitive commercial offer means that we can keep costs down as well as reduce our environmental impact - a great result for our customers."

In 2016, Ørsted also announced that it would supply renewable electricity at no additional cost premium, so that UK businesses can achieve their sustainability ambitions without commercial disadvantage.

Jeff Whittingham, managing director at Ørsted Sales (UK), commented:

"Ørsted is driving the transition to low-carbon energy systems in the UK, and we believe that businesses should have access to renewable electricity supply without incurring additional cost.

“Naturally, we are delighted that Northumbrian Water shares our ambition of creating this greener energy future. It's exciting that such a large and trusted UK supplier places such a strong emphasis on sustainability."

Northumbrian Water Limited supplies 2.7 million customers in the North East with both water and sewerage services, trading as Northumbrian Water, and 1.8 million customers in the South East with water services, trading as Essex & Suffolk Water.

In the most recent survey by the Consumer Council for Water, Northumbrian Water was named the UK's most trusted water company by its customers. 2017 also saw Northumbrian Water named the world's most ethical water company for the seventh successive year.

Headquartered in Denmark, Ørsted employs 5,600 people, including over 900 in the UK, and develops, constructs and operates offshore wind farms, bioenergy plants and waste-to-energy solutions.