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Success Story

City of Gresham Wastewater Treatment Plant, Gresham

Estimated annual savings: $500,000

The City of Gresham Wastewater Treatment Plant achieved net-zero energy consumption after more than 10 years of energy-efficiency and renewable power investments. The wastewater treatment plant is the first in the Pacific Northwest to generate the same amount of electricity as it consumes on-site over a year. Learn more about the Gresham wastewater treatment plant’s net-zero accomplishments in this video, done in collaboration with Climate Solutions.

The plant achieved its goal through the use of two, 395-kilowatt co-generation engines fueled by biogas produced from the anaerobic digestion of wastewater solids, a 420-kilowatt ground mount solar electric system, and increased production of biogas from the co-digestion of fats, oils and grease received from area restaurants and food processers. The facility rounded out its net-zero efforts with multiple energy-efficiency investments. Energy Trust provided long-term technical assistance, project development support and more than $1 million in cash incentives, and the Oregon Department of Energy contributed additional funding.

Learn more about how biogas can help fuel businesses, farms and municipalities managing organic matter »