2 major microgrid solar-battery storage projects underway in the Sonoma, Napa counties

When the Kincade Fire roared through Sonoma County in 2019, the massive power failures forced the U.S. Coast Guard to shut down its training facility near Petaluma, the largest of its kind on the West Coast, for five days.

The center trains 3,500 students a year, employs 350 people and is home to 500 families.

Before the fire, the Coast Guard had installed 855-kilowatt solar panels providing 1-megawatt hour on the campus. But the agency has never had the capability to store power for use in emergency situations.

But now the Coast Guard has broken ground on a microgrid solar storage project designed to power the 837-acre, 810,000-square-foot Tracen training center, which will keep the facility operating in wildfires and planned power outages.

“Thrust into five days of darkness, we were unsure when we’d be able to return to fully mission capable,” Capt. Steven Ramassini, the facility’s top commander, told attendees at the Jan. 28 groundbreaking.

A microgrid acts as a small, self-contained electric grid that can keep essential community services running during failures on the main power grid, drawing power from panels then storing it in backup batteries.

The $36.1 million capital investment includes a 5-megawatt solar array and battery energy storage system capable of generating 11.6 megawatt-hours through four large battery packs.

The project will also encompass lighting fixture improvements, HVAC equipment upgrades, adding controls in 10 buildings and installing a fuel tank with a generator to serve as a backup to a backup over a 5-acre grass field on campus.

Collectively, the system will allow the Coast Guard to be self-sufficient over at least a 10-day period in the event of a disaster, when used with energy conservation efforts.

The Coast Guard estimates it will save $1.2 million a year on its energy bill from the microgrid system in which it teamed up with three U.S. Department of Energy national labs, the Federal Energy Management Program and the Defense Logistics Agency Energy to plan the project. In addition, Ameresco, — a Boston clean tech company — was tapped to provide maintenance for the system over the 21 years on the contract.

Napa Valley zero-emissions microgrid

The Coast Guard is just one of several microgrid projects underway in the North Bay. Another is at Castello di Amorosa winery near Calistoga.

The company last month had a $1.4 million solar and battery microgrid installed, which is estimated to offset about 80% of energy usage. The system includes 1,232 photovoltaic panels on a slope that was significantly burned when the 2020 Glass Fire roared across the valley, burning a wine warehouse on the property but sparing the landmark stone castle and other buildings. The panels have installed generating capacity of 450 kilowatts, paired with a 556-kilowatt four-hour battery.

“This enormous investment is an important element of our commitment to become as self-sufficient as possible while minimizing our carbon footprint and helping with the climate change crisis,” President Georg Salzner in a statement about the installation, designed by Centrica Business Solutions, Recolte Energy and 127 Energy.

Over the past three years, the winery has experienced roughly two dozen notable power failures, particularly during the height of fire season (August–September) and into winter, according to General Manager Jim Sullivan. The outages can last up to a day or a week, and during the Glass Fire the winery lost power for about a month.

The winery uses diesel generator during the outages, but that limits operating capacity, Sullivan said. While the generator will continue to be the facility’s main backup power source, it’s expected to work together with the new battery, particularly when PG&E gives warning of a public safety power shut-off.

“We plan to ensure batteries are charged and ready,” Sullivan said. “We will likely cycle between generator use and (solar and battery) use during these events. The real benefit to having the batteries is it eliminates stress on our generator, reduces diesel consumption and gives us time to repair the generator, as necessary.”

The battery system can provide four to five hours of power by itself. It's life is estimated to be at least 10 years.

Earlier examples of solar and battery pairings in the wine business include Purple Wine + Spirits and Jackson Family Wines. Purple in 2016 installed a battery system to store power from its existing solar hot water and electricity system at its Sebastopol production facility. Jackson in 2012 put in a similar solar power and water system at its Sonoma County airport facilities, and in following expanded photovoltaic arrays and added battery storage.

California sets renewable record

The private and public projects come as California made history by hitting a high mark on April 24, 2021, with 94% of the state’s electricity generated from renewable sources, the state’s energy arm found.

“2021 was a banner year for energy storage. This is the year, really, when everything lined up,” California Energy Commission spokeswoman Lindsay Buckley said.

The state, which marked a goal of 1 million solar roofs installed in 2020, continues to rush to take advantage of price drops and sunny days.

“Even with developers stepping up, there’s so much sun we’re wasting,” Buckley said.

Under the state’s Electric Program Investment Charge (EPIC), the state’s clean energy research and development program earmarks $130 million each year in funding for projects that advance sustaining the environment and make the electric system affordable. From 2012 through 2020, EPIC has supported more than 380 projects with $846 million in funding, resulting in $3.5 billion in private investment raised by rewarded organizations.

Since 2012, EPIC has invested in more than 40 microgrid projects to test the readiness in a wide variety of venues, from fire stations and hospitals to jails and tribal communities.

These systems combine locally generated electricity with energy storage systems.

U.S. Rep. Jared Huffman, D-San Rafael, is pleased with the organizations that have come forward to advance the clean energy cause, but he believes much more needs to be done.

“We’re way behind. Do I celebrate this? Yes,” Huffman said days after attending the groundbreaking ceremony.

“This is a project that’s especially exciting,” he said at the ceremony. Kincade will not be the last time we are confronted with a disaster with this kind of disruption of services we take for granted.”

Amplification, Feb. 8, 2022: The battery energy storage system at Castello di Amorosa is rated for a four-hour discharge.