Veolia is helping Scottish Water make one of its water treatment facilities more energy self-sufficient.
Since 2015, the global resource management company has extended the Seafield Wastewater Treatment Works’ ability to generate its own energy from 55% to around 85%.
It has done this by boosting the renewable energy derived from a combination of the anaerobic digestion of sludge and biogas-fired combined heat and power (CHP) plants.
A thermal hydrolysis process has further increased biogas production by around a tenth and an additional CHP unit means this can be used to generate more power.
Veolia says the plant has reduced its energy costs by 50% and on several days in 2017, used no electricity from the grid at all.
It treats waste for a population equivalent of approximately 850,000 people from Edinburgh and the surrounding area, treating enough water to fill 121 Olympic sized swimming pools every day.
John Abraham, Chief Operating Officer Water at Veolia, said: “Recent estimates indicate that the water industry could be self-sustaining for electricity by harnessing the 11 billion litre annual flow of waste water.
“In this way we can make a significant contribution towards delivering renewable energy targets, while keeping the lights on and taking pressure from the National Grid.”