Wastewater treatment requires a lot of energy, and energy is expensive. In an effort to reduce costs and greenhouse gas emissions, NapaSan implements projects at the treatment plant to increase energy efficiency and generate our own electricity.
When the solids that are removed from the wastewater are treated (digested), it produces a lot of methane gas. Lucky for us, methane gas is a great energy source. NapaSan installed generators that can burn this methane to produce electricity that then powers the wastewater treatment process. This process, called cogeneration, produces electricity that replaces the electricity and natural gas that would normally be purchased from PG&E.