written 15 June, 2025
published 22 June, 2025
A new grid scale solar array is being constructed near the north end of Redemeyer Road, east of Ukiah. This 4 megawatt array is owned by Renewable Properties, which builds and operates solar systems in 14 states. The Ukiah array has been in the planning and permitting stage for several years. Construction is close to completion, with all the panels and their single axis tracking systems now installed. Interconnection to the grid has yet to happen, but the power is already contracted to be sold to Sonoma Clean Power.
Averaged over a full year, this facility will produce about 16 megawatt hours of power each day. To put this into perspective, the output is about 5 percent of Ukiah's daily load, or 1 percent of Mendocino county's daily load. This is the largest array in the area, but relatively small compared to arrays in the Central Valley, which are 25-100 times larger.
The next largest array in the valley is at Mendocino Community College, which has had a 1 megawatt array in operation for over 15 years. The daily solar power curve peaks mid-day, and is out of synch with the College power load, which extends long past sunset. When operating, the array powers the load at the moment and any excess energy is sold back onto the grid. This has supports about half of the College's daily power consumption, and evening power is purchased back from PG&E.
A month ago, the College added a 750 kilowatt hour battery to the system. This allows some excess energy collected during the day to be stored for use in the evening. It is expected this will now support about 70 percent of their load. A recent energy audit at the College indicated equipment upgrades which would reduce their load by about 20 percent. After the upgrade, their array and storage will be close to supporting their entire load.
While the Redemeyer and College arrays are the largest in the Ukiah valley, three campuses of the Ukiah Unified School District have 250 kilowatt parking lot canopy arrays. Several businesses have large rooftop solar, such as Factory Pipe, Raley's, Walmart, and Costco, to name a few. About 160 homes and small businesses within Ukiah have rooftop solar. While all this helps support our local power consumption, it is just a start, compared to what is needed.
For example, Ukiah Electric could do what the College did, and install hardware to help support their own electrical load. The City would require a much larger array, but any size array would help. NCPA, the agency which contracts to provide the City with power, has already told the City to begin planning to produce at least 15 percent locally. This would need more than 10 megawatts of array, using as much as 40 acres of land. There are locations within the City limits, and the possible annexation would add more real estate opportunities, but the City is compact, and space is limited.
Another viable option is to begin adding more local storage into the City utility mix. Even though Ukiah charges the same retail rate throughout the day, the wholesale power delivered in the evening is as much as 10 times more expensive than mid-day. Since long lasting grid scale batteries have become commercially available, it is now cheaper to store mid-day solar power to use in the evening. Furthermore, the solar production in Ukiah is unevenly distributed throughout the system, and some circuits get overloaded mid-day. Strategically placed storage would eliminate that issue.
It may seem foolish to suggest moving toward local power resilience, given the current political stance from the Federal government. The party dogma is climate change is just a "Woke fad", and every effort to even monitor the situation, let alone begin to deal with it, is being shut down. To my mind, this is an insane denial of reality, which guarantees suffering.
The insurance crisis will get only worse as long as the underlying cause is ignored. Disbanding the Federal Emergency Management Agency won't stop hurricanes, fires, and floods, but everyone impacted will be worse off without coordinated help. Shutting down the weather service doesn't change what happens, but people are less prepared for what is coming.
At some point, foolish denial is inevitably broken by reality. The more we can do locally, despite the denial, the better off we will be in the long run.
