Biogas To Power Wastewater Treatment Plant

A new 60,000-pound biogas generator that utilizes methane from the sludge treatment process at Hornsby Bend Wastewater Treatment Plant is currently being installed and will be able to consistently generate 700 kilowatts (kW) of power, more than the 500 kW needed to run the treatment plant. The excess electricity produced and fed back into the electric grid will enable Austin Water, which manages the treatment plant, to receive a credit on its electric bill. See photos.

Because the generator uses the methane and not a fossil fuel, the electricity produced is considered renewable energy. It is estimated that more than 4.4 million kilowatt-hours of electricity will be generated annually, the equivalent of powering 370 average-sized Austin homes year round. The clean generation also will reduce carbon dioxide emissions by 2,867 tons or the equivalent of avoiding 5 million vehicle miles traveled in Austin.

The generator is funded separately from a federal stimulus grant awarded Austin Energy but is related to green infrastructure improvements currently under way at Hornsby Bend by Austin Water to enhance the energy efficiency of the biosolids processing and increase biogas production. Hornsby Bend receives the sewage solids reclaimed from the millions of gallons of wastewater that Austin’s wastewater plants treat every day.

All of Austin’s sewage solids are pumped to Hornsby Bend where they are treated to kill pathogens and the resulting biosolids are recycled as the compost product ‘Dillo Dirt.’