With 37GWh of electricity generated, carbon emissions were down 3.5 per cent compared to the previous year, and 16 per cent overall since 2006/07.

The data, unveiled in its 2016 Sustainability Report, comes as Scottish Water secured £9 million to boost 24 existing solar sites. The water utility company already has 25 sites with hydro turbines, as well as 18 wind-powered sites.

The schemes form part of a £3.5 billion six-year investment plan to improve drinking water quality, enhance the environment and support the economy.

Chris Toop, general manager for Scottish Water’s energy programme, said: “These investments help to reduce the long-term cost of providing vital water and wastewater services to customers.

“The benefit from our whole energy programme now exceeds £6m annually and we have ambition to do more.”

Andrew MacDonald, head of Scottish Water Horizons, added: “We continue to harness the vast natural and renewable energy resources that Scotland has.

“As a Hydro Nation we are driven to extract sustainable benefits from every phase of the water cycle using both proven and innovative technologies.”