An award-winning ABB medium voltage drive has reduced the energy consumption of the aeration blowers at a US wastewater treatment plant by more than 1 million kilowatt-hours a year – a reduction of more than 30 percent that saves the city utility $75,000 annually.
The ACS 2000 medium voltage variable speed drive was installed in July 2011 and has achieved some remarkable results within its first year of operation at the City of Beloit Water Pollution Control Facility (WPCF) in Wisconsin, United States.
The facility treats an average of 5.5 million gallons (20.8 million liters) of wastewater a day from the city’s 37,000 inhabitants, as well as industrial waste from local businesses and biological waste from food processing plants.
Like many wastewater treatment plants, Beloit uses a conventional activated sludge process for treating the wastewater. At the heart of this process are the aeration basins in which microorganisms break down the organic matter in the wastewater. These bacteria require oxygen to survive, which is provided by huge aeration blowers that blow air through diffusers at the bottom of the basin.