Solar Switch at California Jail Spurs Energy Savings Without Upfront Spending
A newly installed carport solar array paired with a battery storage system at the Monterey County jail is expected to generate more than 2,000 MWh of clean electricity annually. | Photo Credit (all): Courtesy of Sunrock Distributed Generation / Mynt Systems
By Charlie Lange
As operational costs continue to climb across public agencies, departmental administrators are constantly looking for ways to minimize budget expenditures and increase taxpayer savings. As power grid issues deepen, infrastructure ages, and prices and demand charges skyrocket, uncovering efficient, sustainable energy solutions is especially critical to municipalities’ bottom lines.
In 2020, the newly established Director of Sustainability for the County of Monterey, Calif., was tasked with identifying energy and sustainability improvements across the county’s operations. When a study on the top 10 highest energy users in the county revealed that the county’s jail in Salinas, operated by the Monterey County Sheriff’s Office (MCSO), sat at the top of the list, the facility emerged as a prime site for improvement, and the county sought a local provider to initiate a pilot program that could kickstart energy savings.
Now, after a years-long development process that included navigating major shifts in federal energy policy, delays due to local flooding and wildfires, and a late-stage fire at a nearby energy storage facility, a new solar-plus-battery storage project is in operation at the Monterey County Jail.
Co-developed by Sunrock Distributed Generation and Santa Cruz–based renewable energy development, engineering, and construction company Mynt Systems, the installation includes a 1.243 MW carport solar array paired with a 1.043 MW / 2.087 MWh Tesla battery system that is expected to generate more than 2,000 MWh of clean electricity annually. This will offset approximately 55% of the County Jail’s annual energy use and reduce carbon emissions by around 1,000 metric tons per year — locking in long-term energy and financial savings while strengthening local grid reliability.
The project was financed by a Power Purchase Agreement (PPA) provided by Sunrock Distributed Generation and is expected to save the MCSO more than $12 million over its lifetime — with zero upfront cost.
Under the terms of the PPA, Sunrock Distributed Generation and its investors own and operate the solar-plus-storage system. The jail then purchases the electricity directly from Sunrock at a fixed rate which is lower than the prevailing grid electricity price, delivering immediate cost savings. This electricity rate is locked in for the lifetime of the project, providing long-term price certainty and protecting the jail from future increases in grid electricity costs.
Claire Broido Johnson, Co-Founder and President with Sunrock, said the PPA financing structure covers future maintenance and performance costs. As part of the agreement, Sunrock and its investors achieve a return on investment based on kilowatts generated — ensuring an ongoing incentive to keep the system running efficiently in years to come.
Broido Johnson added that this arrangement allows administrators within the MCSO to focus on their day-to-day operations and rest assured that the system will perform as designed.
“It costs a lot to build, operate and maintain these systems, and that’s the last thing jail operators should be thinking of,” said Broido Johnson.
Rob Hymes, Chief Development Officer with Mynt Systems, said the installation within an active correctional facility presented its own challenges related to security, and involved numerous site visits throughout the development process to plan and sequence work without interrupting operations. The jail’s placement adjacent to a hospital also amplified safety concerns during installation, especially related to Monterey County’s high standards for fire safety. Project partners worked closely with the County of Monterey’s Health and Safety Division and Emergency Preparedness teams to ensure a conservative, safety-first approach to the project.
Those considerations heightened after a January 2025 fire involving nickel manganese cobalt (NMC) batteries at the nearby Moss Landing energy storage facility. While the County Jail’s system involves a completely different lithium iron phosphate (LFP) battery technology, recognized for its much lower risk of thermal runaway compared to other battery types, public and industry scrutiny increased in the aftermath of the Moss Point incident.
Hymes said Mynt Systems held focus groups with county supervisors to ensure them of the safety and stability of LFP technology. He also said that as a local, Monterey County-based company, Mynt Systems placed an added importance on seeing the project safely through to fruition and helping the community achieve critical energy savings for years to come.
Hymes ultimately credits the MCSO for placing its trust in Mynt and shepherding the project through completion amid the myriad project challenges.
“The individuals in the Sheriff’s Office were our biggest advocates,” he said. “They kept the project alive through the various delays and pushed it over the top.”
Hymes and Broido Johnson are both pleased to have played a role in helping the MCSO and County of Monterey achieve a more sustainable path forward.
“Bringing this project online shows what’s possible when strong public partners work with experienced developers and long-term capital,” said Hymes. “This system was designed with safety at its core and is projected to deliver millions of dollars in savings that can be reinvested into sustainability and community resilience.”
Hymes also said the project was particularly impactful to him personally, as it presented an opportunity to serve the local community and bring some attention to under-the-radar sustainability considerations.
“A correctional facility might be low on the list when talking about sustainability, but this project really highlights how important it is,” said Hymes.
Broido Johnson echoes that sentiment. “Sunrock is dedicated to helping local businesses and municipalities unlock the cost and environmental benefits of solar-plus storage systems with zero upfront cost, and, personally, it’s what I’ve spent my life’s work doing. We are delighted to partner with Mynt Systems to bring this important project to fruition.”
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