San Bernardino County, CA

Customer Type

Water District

Facility Type

Water Treatment Plant


Backup Power, Energy Cost Reduction

Commercial Operation Date

Spring 2021

Energy Storage System Size

464 kW / 1856 kWh

Stockmans Leverages Stem to Enter California’s Energy Storage Market

Stockmans is an electrical contractor based in San Luis Obispo that provides solar, microgrid, and new construction services. Since 2011, it has delivered over $20 million in publicly funded energy projects for agricultural, industrial, and government clients. Prior to engaging with Stem, it had limited exposure to energy storage.

Stem helped Stockmans quickly get up the learning curve on energy storage, providing crucial educational and sales support that helped the company land its first major energy storage project. The 1,856 kWh system, at a water district in San Bernardino County, will provide backup power to the facility and better service to customers, in line with state resilience and climate goals.


With blackouts and wildfires continuing to affect millions of Californians, Stockmans wanted to offer energy storage to its customers as a means of enhancing their energy resilience. Its interest piqued when, in the wake of 2018’s disastrous wildfire season, California significantly expanded its energy storage incentives. The most generous of these, under the state’s “Equity Resiliency” program, targeted critical facilities, such as fire stations and water treatment plants, located in high fire-threat districts and serving disadvantaged communities.

But as a small shop, Stockmans lacked expertise. Its prior experience with energy storage was limited to very small, off-grid systems. While it was expert at grant applications, it was unfamiliar with California’s Self-Generation Incentive Program (SGIP) which distributes Equity Resiliency funds. And after several negative experiences with smaller storage providers that went out of business or were otherwise challenging to deal with, Stockmans was looking for an industry leader with a proven track record.


Stockmans reached out after attending a Stem webinar on California’s energy storage incentives. In subsequent conversations, Stem answered questions, recommended target customers, and provided additional resources and sales collateral. 

Stockmans soon found its first potential customer – a water district in California’s San Bernardino County. But it was still new enough to storage that involving Stem in its sales process could be materially beneficial. At Stockmans’ request, Stem presented to the district’s board of directors, answering detailed questions about how Stem’s backup power solution would build resilience at the treatment plant, as well as the ins and outs of state incentives and system installation and operation. The project was approved.

Meeting Stockmans’ needs now involved meeting those of its client. The plant’s diesel backup generator hasn’t always supplied power to critical pumping loads, and it takes several minutes to warm up. Stem’s expert engineering team worked closely with Stockmans to design an energy storage system that will back up critical loads for as long as four hours before transferring to the diesel generator. 


When it comes online, in spring 2021, the energy storage system’s main benefit will be its improvement in supplying reliable power to the plant’s critical pumping loads during grid outages. And under normal, non-outage conditions, energy storage will provide utility bill savings by reducing demand charges and shifting energy use to off-peak times.

More broadly, the district’s customers will benefit from better, more reliable service with fewer greenhouse gas emissions – just as the Equity Resiliency program intended.

For Stockmans, working with Stem has provided exactly the entry it wanted into California’s energy storage market. Stem’s expertise enabled the company to get up a steep learning curve in a short time, and Stem’s support and name recognition continues to be helpful in sales efforts. The companies are now pursuing several diverse projects – for schools, agricultural clients, and other utility districts – while eyeing broader trends at the intersection of storage, solar, and electric vehicles.

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