Pasadena Kicks Off Its First Big Battery at a Plant Dating to 1907

The 25-megawatt Glenarm battery, backed by up to $9.66 million in state money, is due to be finished by mid-2027.

Pasadena’s streetlights first ran on electricity from a steam plant on Glenarm Street, at the end of Raymond Avenue, more than a century ago. On Wednesday, the city kicked off construction of its first utility-scale battery on that same ground.

The battery will hold 25 megawatts for up to four hours, soaking up carbon-free power and sending it back out during the evening peak, according to a city announcement on cityofpasadena.net. It’s built from lithium iron phosphate cells and is due by mid-2027, one piece of Pasadena’s push toward an all carbon-free power supply.

State Sen. Sasha Renée Pérez and Assemblymember John Harabedian spoke at the kickoff with Mayor Victor Gordo, Councilmember Jason Lyon, Interim City Manager Matthew E. Hawkesworth and David Reyes, general manager of Pasadena Water and Power. The state’s stake goes past the speeches: the California Energy Commission has backed the project with up to $9.66 million from its Distributed Electricity Backup Assets program.

The idea is timing. “The battery storage installation will allow us to store excess solar energy on the grid and use it during peak demand,” Kelly Nguyen, the utility’s assistant general manager for power supply, said in a June 2024 city release.

That release set the city’s target at 100% carbon-free power by the end of 2030. It also said the battery should last at least 15 years.

The deal isn’t a straight purchase. Glenarm BESS LLC, a special-purpose company created by EPC Energy Inc., designs and builds the battery and sells its capacity to the city, under an arrangement the City Council approved in June 2024. Pasadena can buy it outright at startup, two years in, or in the fifth year or any year after, the city’s planning page for the project says.

Neither city announcement puts a total price on the battery. The state grant, the 2024 release said, is meant to help offset the cost of the equipment and installing it. The buyer on the other end is a city-owned, not-for-profit utility with more than 65,000 electric customers in Pasadena.

The battery takes up about 0.59 acre inside the Glenarm Power Plant. The city’s environmental study flagged possible effects tied to hazardous materials, soils and geology, and cultural and tribal resources. It concluded that mitigation would keep all of them below the significant mark, and a city hearing officer set a public hearing on the permit for March 2025.

Pasadena has thrown a kickoff at Glenarm before. In July 2014 the city broke ground on GT-5, a 71-megawatt gas unit pitched partly as a fast-starting partner for wind and solar when they faded, POWER magazine reported. A gas turbine then, a battery now: two answers, a decade apart, to what the city does when the sun goes down.

GT-5 was due in June 2016. Record December rain, a late equipment shipment from Houston and months of work to get its emissions under California’s limits got in the way, and the ribbon-cutting came on Feb. 24, 2017. The battery’s mid-2027 date has a local record to beat.

The plant’s first job, starting July 4, 1907, was lighting Pasadena’s streets. If the battery shows up on time, its job will be the evening, too, running on power the sun made that afternoon.

Source: cityofpasadena.net, retrieved October 9, 2026. Other sources: cityofpasadena.net (2), cityofpasadena.net (3), powermag.com.