Two steam plants and a revolutionary water recovery system in San Francisco’s commercial core
Clearway Community Energy San Francisco supplies energy-efficient and environmentally-sound district heating services to buildings in a 2-square mile area of the central business district of San Francisco, California.
Clearway Community Energy San Francisco’s two downtown plants produce steam and pipe it to approximately 180 customers for space heating, domestic hot water, air conditioning, and industrial process use. Clearway Community Energy San Francisco serves a total of more than 37 million square feet of space in the city’s commercial core. Located at 460 Jessie St. and 1 Meacham Place, both plants use boilers fueled by natural gas as their primary fuel with #2 diesel as a backup fuel. The system’s CHP equipment generates 500 kW of electricity, essentially making the plant energy self-sufficient.
Water Reclamation Project
The water reclamation project required collaboration between the City of San Francisco Public Utilities Commission (SFPUC), the local subway operator, and CCESF to recover over 30 million gallons of groundwater per year. The water is transported from the Powell Street Station to the CCESF plant via a newly installed underground pipeline, then treated to levels of purity that would be boiler-grade, a much higher standard than regular drinking water. Groundwater treated for boiler makeup water is a complicated and expensive proposition. For the new system to be successful, it needed multiple steps of purification to remove trash, dirt, biologicals, minerals, and chemicals. It also required the use of an advanced front-end filtration plant, which integrates with the existing water softening equipment at CCESF, and a new and innovative reverse osmosis (RO) treatment system.
Clearway financed the project on the balance sheet and self-performed the construction of the overall system. This project reduced Clearway Community Energy San Francisco’s domestic water use by 30%.