Caldwell Wastewater Treatment Plant

A solar+storage installation at the wastewater treatment facility serving the Borough of Caldwell, New Jersey, will keep untreated wastewater from entering local waterways during extended power outages. During emergencies, the solar+storage system will work in concert with existing diesel generators to provide up to 10 days of backup power to the Borough’s wastewater treatment plant.

The solar+storage system will also make economic sense for the facility and utility. Wastewater treatment plants are highly energy intensive facilities that can be excellent candidates for renewable energy projects. Under normal conditions, the solar panels deliver power to the grid, saving money by reducing the volume of power that the facility must purchase to operate.

Additionally, the battery can be used for grid services that save money for the utility, Public Service Electric and Gas Company (PSE&G), like monthly and annual peak shaving that reduce the costs of supplying power during times of high energy demand. The battery can also be used to participate in regional ancillary services markets, such as PJM’s frequency regulation market that pays utilities to use energy storage to help regulate electricity supply and demand. (Learn more about storage and ancillary services Clean Energy Group’s report, Energy Storage and Electricity Markets.)

The Caldwell solar+storage system combines an 896-kilowatt solar power system, composed of 2,682 solar panels provided by Advanced Solar Products, and a 250-kilowatt / 1-megawatt-hour battery system from Eos Energy. The system was developed as part of PSE&G’s Solar 4 All program, which includes a 3-megawatt carve-out dedicated to developing resilient power technologies capable of providing backup power.

The Solar 4 All program is designed to promote projects that integrate solar with other technologies to reduce the impact solar has on the grid or increase reliability and grid resiliency for critical facilities during prolonged power outages. There are two other PSE&G solar+storage projects within this program: a project installed at Hopewell Valley Regional High School allows the school to serve as a warming or cooling station for the public during an extended power outage and a solar+storage system at Cooper University Hospital in Camden, NJ will provide backup power for refrigeration needed for vital pediatric medications at the hospital.