The East Bay Municipal Utility District (EBMUD) hired Carollo to review alternatives for expanding its existing 7.0-MW power generation station (PGS) to utilize increased digester gas production at its wastewater treatment plant. Project goals included maximizing power and heat production using an expected gas production of 4,000 standard cubic feet per minute (scfm). The resulting project is an additional new power generation station, PGS II, to operate in parallel with the existing PGS.
The new PGS II will initially contain two 4.5-MW Solar Mercury 50 gas turbine generators and all appurtenant devices to generate 9 MW of additional electrical power. The design of PGS II accommodates an additional third 4.5-MW gas turbine generator to bring the total capacity of PGS II to 13.5 MW. The design includes gas treatment equipment to remove siloxane compounds from the digester gas and gas compression equipment to provide the required pressure for the gas turbines. Carollo also provided electrical equipment to provide dual redundant power feeds from PGS and PGS II to ensure uninterrupted power generation and electrical power redundancy to the treatment plant.