Galafoot waste water treatment works has become one of the country’s most self-sufficient energy sites.
The Galashiels-based plant on the banks of the River Tweed, operated by Scottish Water, now generates more energy than it uses.
The site creates electricity from sewage sludge and generates, on average, more than 18,000 kWh/week of renewable energy which is enough to power 204 homes for a year.
The waterworks, which employs two full-time operators, processes an average 150 m3 of sludge every day serving around 27,000 people across the region.
Brian Reavely, known as Fudge, has worked as an operator at Galafoot for 27 years and says one of his proudest achievements is seeing how the site has become as green as it can.
The 52-year-old from Galashiels said: “Treating waste uses a lot of energy, if you think about what we are dealing with and the different processes it has to go through you get an idea. Added to that this site operates round the clock every day, so it needs a lot of power.
“We take our environmental responsibility very seriously here, even down to recycling items like cans and bottles and packaging in our kitchens. And one thing we have started doing is working with our neighbouring works to ensure that the sludge dry solids are as high as possible when they arrive at our site - to save on energy use, reduce our carbon footprint and minimise vehicle movements.
“Things like this can make a real difference. The imported sludge is mixed with the on-site, indigenous sludge. This feeds the digester which produces methane gas which is the fuel for the 124 kW capacity CHP.
“We are very green-aware here and proud of what has been achieved, so much so I have made signs reminding us of how self-sufficient the site is.”
The site imports a small amount of power to the site, but the consumption of imported power to the site has dropped by two thirds in the past three years.
More than 70 of Scottish Water’s water and wastewater treatment works are either self-sufficient or partly sufficient in their power requirements, leading to lower operating costs and a more sustainable business.
Galashiels is one of the top five that offset most of the site’s use as well as being able to export to the grid– others include Glencorse water treatment works, near Edinburgh and Loch Turret water treatment works in Perth and Kinross.
To mark the renewable generation milestone a plaque will be put up at the Galafoot site.
Simon Parsons, Scottish Water’s director of strategic customer service planning, said: “To keep the cost of our services as low as possible it is essential we develop our approach to energy management and continue to reduce our carbon footprint.
“Where appropriate, like at Galashiels, we’re exploring opportunities to export energy to the national grid, showing that it’s possible to maximise the economic advantages of Scotland water resources in the spirit of a Hydro Nation and contribute to national renewable energy targets.”
“Galashiels is a wonderful example of what can be achieved.”
Three years ago Borders College in Galashiels became the first organisation in the UK to benefit from a waste water heat recovery system, installed in partnership between Scottish Water Horizons and Shark Energy. It extracts the natural warmth contained in waste water in the sewer and transfers the heat to the clean side of the heating system via a heat exchange mechanism. The recovered heat is then amplified via pumps to generate appropriate temperatures for use in buildings.
The heat produced is being sold to Borders College producing savings in energy, costs and carbon emissions. The system now provides around 95 per cent of the heat needed by the Galashiels campus.