In our first decentralized energy success story of the new year, a wastewater treatment plant in Scotland achieved 85 per cent energy self-sufficiency in 2017.
Scottish Water’s Seafield Wastewater Treatment Works (WwTw) increased its on-site power generation from 55 per cent according to Veolia, which operates the plant’s combined heat and power (CHP) system.
The system runs on sludge from an anaerobic digestion plant and biogas and, at various points in 2017, helped the facility to run completely independently from the grid, Veolia said.
The Seafield WwTW processes around 300 million litres of wastewater per day. Plant operators have targeted energy self-sufficiency and, in the process, have already reduced the facility’s energy costs by 50 per cent, Veolia said.
In partnership with Scottish Water, Veolia said it has introduced a wide range of measures to derive renewable energy from sludge. Measures installed to date include a thermal hydrolysis process that has increased biogas production by around 10 per cent, investment in an additional CHP unit to provide greater energy generation and to take advantage of the additional biogas, and a further 3 per cent increase in biogas yield.
John Abraham, COO for 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. 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.”