Scottish Water’s Seafield Wastewater Treatment Works achieves energy self-sufficiency

Scottish Water has announced that its Seafield Wastewater Treatment Works (WwTW) has been able to achieve energy self-sufficiency.

Seafield attained full self-sufficiency during 2017 when it used no electricity from the Grid.

The achievement was possible with the introduction of Veolia’s wide range of measures to derive renewable energy using sludge.

Veolia has been extending its services to Scottish Water’s site since 2015.

The renewable energy is derived from a combination anaerobic digestion of sludge and biogas fired combined heat and power (CHP) plants.

Seafield WwTW treats waste for approximately 850,000 people from Edinburgh and the surrounding area, which is equivalent to 300 million litres of wastewater every day.

The target set for energy self-sufficiency enhances sustainability and lowers carbon emissions.

The implemented measures include a thermal hydrolysis process that has increased biogas production by around 10%, investment in an additional CHP unit to provide energy generation and use the additional biogas, and a further increase of 3% in the yield of biogas.

The water industry uses nearly 3% of UK generated electricity for pumping, water treatment and waste management, which directly contributes around 1% of the UK’s greenhouse gas (GHG) emissions.

Veolia chief operating officer water John Abraham commented: “Recent estimates indicate that the water industry could be self-sustaining for electricity by harnessing the 11 billion litre 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.”