Veolia helps Scottish Water achieve energy self-sufficiency

By Veolia | January 03, 2018

Veolia, the global resource management company, is now helping Scottish Water to achieve the target of energy self-sufficiency at its Seafield Wastewater Treatment Works, WwTW, the largest treatment works in the east of Scotland.

Since 2015 Veolia has extended the site’s capability to generate its own energy from 55 percent to around 85 percent in 2017 by boosting the renewable energy derived from a combination anaerobic digestion of sludge and biogas-fired combined-heat-and-power (CHP) plants. In fact full self-sufficiency has already been achieved at various points during 2017 when Seafield used no electricity from the Grid.

Seafield WwTW treats waste for a population equivalent of approximately 850,000 people from Edinburgh and the surrounding area which equates to 300 million liters of wastewater every day—enough to fill 121 Olympic sized swimming pools. By implementing a range of innovations and increasing efficiency the target of energy self-sufficiency has been set as the practical target and will further sustainability and lower carbon emissions.

The advances to date mean that the Seafiled site has also reduced its energy costs by 50 percent, which will help meet the value-for-money consumer criteria set for the industry. The water industry is the fourth most energy intensive U.K. industry and uses around 3 percent of U.K. generated electricity for pumping, water treatment and waste management which directly contributes around 1 percent of the U.K.’s greenhouse gas (GHG) emissions. Working in partnership with Scottish Water, Veolia have introduced a wide range of measures to derive renewable energy using sludge as a valuable resource. Measures installed to date include a thermal hydrolysis process that has increased biogas production by around 10 percent, investment in an additional CHP unit to provide greater energy generation and to take advantage of the additional biogas, and a further 3 percent increase in the yield of biogas.

Commenting on the continuing development, 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 liter annual flow of waste water. Our application of technology to this process demonstrates how we can help deliver greater sustainability for the industry using waste water to energy systems, and also meet water industry carbon reduction targets. 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.”

Recent estimates indicate that the water industry could be self-sustaining for electricity by harnessing the 11 billion liter annual flow of waste water

More advanced technologies now mean that biogas from all the available sewage could deliver an estimated 1,697 GWh—enough electricity to power over half a million homes, increasing the resilience of the National Grid and helping to control energy bills.