The North Bay Energy Storage Project is a proposed 200-megawatt (MW) / 800-megawatt-hour (MWh) battery energy storage systems (BESS) facility located on roughly 15 acres in unincorporated Sonoma County near the City of Petaluma.

The North Bay Energy Storage Project is being proposed by Bolero Energy Storage, LLC, a wholly owned subsidiary of Strata Clean Energy (Strata). Strata is a family-owned, U.S.-based company started in 2008. It is a fully integrated renewable energy company, with development, engineering, construction and operations/maintenance under one roof. To date, Strata has developed 4 gigawatts of projects and currently owns, manages, and operates renewable energy facilities located throughout the U.S.

For more information about Strata Clean Energy, please visit the company’s webpage at https://www.stratacleanenergy.com/.

The North Bay Energy Storage Project is an electrical grid-connected resource that uses lithium-ion batteries to support the healthy operation of the grid and the integration of renewable energy. The Project will use batteries to store excess energy from the grid. For example, solar and wind energy production are typically high during the day. Extra energy from these and other sources can be stored by the Project and discharged back to the grid at night. Generally, the Project would discharge the stored energy back onto the electrical grid when energy demand is more than energy supply

The North Bay Energy Storage Project will be comprised of lithium-ion batteries housed within standardized, purpose-built, all-weather outdoor enclosures. Each battery enclosure will be paired with cooling systems, safety systems, inverters, controls, metering/telemetry, transformers, and accessory equipment. The battery enclosures will be arranged in rows and will be painted a shade of green (such as forest green) to blend into the surrounding vegetation.

On average, the battery enclosure will be approximately 10 feet in height and roughly 8 feet in width. The lengths of the enclosures vary due to the modular nature of these units. The number, size, layout and capabilities of each battery enclosure varies depending on the final system manufacturer.

The Project also includes the installation of an onsite substation located along the eastern edge of the Project site. This onsite substation will consist of high voltage electrical equipment that will connect the Project via the adjacent PG&E Lakeville substation to the electrical grid through a short generation-tie transmission line (gen-tie line). The Project may also include water storage tanks and associated fire suppression equipment.

Battery energy storage technologies can help achieve California’s clean energy goals by helping:

• Reduce emissions of greenhouse gases by capturing excess renewable energy generation for use later, reducing or avoiding the curtailment of renewable energy and displacing the use of fossil fuels to generate electricity.
• Reduce demand for peak electrical generation by replacing the use of natural gas-fired peaking plants during the highest electricity demand hours.
• Defer or substitute for an investment in generation, transmission and distribution by absorbing and compensating for fluctuations in energy from solar and wind energy, which complements existing infrastructure to meet energy system needs.
• Improve the reliable operation of the electrical transmission and distribution grid by providing several services to the electric grid, including frequency regulation, voltage support, resource adequacy and demand charge reduction.

The Project, along with other energy storage facilities located throughout the state, will be an important next step in transitioning California’s electrical grid to 100% renewable energy. The primary purpose of the North Bay Energy Storage Project is to better utilize intermittent renewable energy generation such as solar and wind by storing energy produced by these clean energy sources when California’s energy demand is lower than its energy supply. The Project will be connected to the electrical grid, and because the state’s electrical supply still consists of a mix of both renewable and non-renewable energy generation sources, the energy stored by the Project will reflect this mix of sources.

As a local electricity resource, the North Bay Energy Storage Project will provide reliable on-demand power for peak needs and renewable integration to the local community and beyond. With the increase in wildfires, mudslides, and high wind events that can cause a loss in power, the Project will help ensure electric reliability in the event of public safety event. During Public Safety Power Shutoff (PSPS) events, the BESS Facility can be available to continue to provide power in Sonoma County and elsewhere. In sum, the North Bay Energy Storage Project will serve as a critical piece of infrastructure to achieve this goal and advance the needs of Sonoma County residents.

The Project will also provide significant economic benefits to Sonoma County and the region. Construction jobs, new property tax revenue, and ancillary economic stimulus will be injected into the community during the construction and operations of the facility. Once the Project is online, Sonoma County will join dozens of other communities across California and the world that are utilizing advanced energy storage facilities to provide on-demand and reliable electricity.

The North Bay Energy Storage Project will be connected to the electrical grid, so when discharged, energy stored by the Project will enter the grid and travel where needed on the local and regional grid. Since electrons follow the path of least resistance, when the battery is discharging, the local load will be served first.

Design of the North Bay Energy Storage Project will consist of a combination of landscaped earthen berms, vegetation, existing topographical variations and natural distance to ensure that visual receptors in the vicinity do not have direct line-of-sight of the battery enclosures.

For safety and security purposes, a limited number of new lights will be installed on the Project site, likely only at the gated entrance of the BESS Facility and within the onsite substation area. Lighting located at the entrance will be automatically controlled to operate between dusk and dawn, while lighting within the onsite substation area will only be illuminated if/when needed for non-routine, unplanned nighttime maintenance activities. All lighting will be downcast, shielded, and energy efficient to comply with all applicable Sonoma County lighting requirements.

At the nearest residential properties, the Project’s noise levels will be about 45 dBA, which is similar to a quiet office setting. The primary sources of noise are HVAC units within each battery enclosure, the Project’s PCS units (transformers), and the onsite Project substation. Operational noise modeling found that Project noise levels at the closest residences will be in the range of approximately 45 dBA or lower, which is consistent with ambient nighttime sound levels already experienced in the vicinity. The Project’s noise operational levels also comply with Sonoma County’s nighttime exterior noise limit of 45 dBA L₅₀ and the City of Petaluma’s limit of 60 dBA.

The only operational air emissions generated by the North Bay Energy Storage Project will be related to the handful of weekly operations/maintenance vehicle trips required to ensure that the Project is operating properly. Charging and discharging of the batteries is emission free and generates no odors.

Yes, some trees will be removed, but the Project includes replacing them in a way that exceeds all legal requirements for tree replacement. There are existing trees in the footprint of the North Bay Energy Storage Project that will be removed. In addition, some trees found in the adjacent windrow located between the Project site and the adjacent PG&E Lakeville Substation will also be trimmed or removed to create adequate vegetation clearances for the Project’s gen-tie line. Trees removed are of varying species, dimension, and health. The Project’s landscape plan includes over 200 new trees and will exceed the County’s tree replacement requirements.

During construction, water will be required for concrete installation, soil conditioning, dust control, and erosion control. As allowed by the County, recycled water would be used in place of domestic water during construction.

Once operational, the Project’s water demand will be limited to landscape irrigation and emergency fire response. The Project will use recycled water from the existing recycled water line on the Project Site for fire control and irrigation.

Use of recycled water for emergency fire suppression purposes may require the use of a pressure tank and booster pumps to provide the required water pressure. In addition, there is potential that emergency fire suppression water may need to be stored on-site within fire protection water tanks. These tanks would be colored with a neutral tone consistent with the surrounding aesthetic environment.

Lithium-ion batteries are not considered hazardous waste by the EPA. Lithium-ion batteries are considered less toxic than lead acid batteries, do not have spill and chemical burn risk, and have a much longer useful life. Lithium-ion batteries are a widely adopted battery technology that has been found in various consumer applications over the past decades and are used in cell phones, laptops, and other household electronics. Unlike traditional household alkaline batteries that are non-rechargeable and may leak due to mistreatment and abuse, rechargeable lithium-ion batteries use a completely different chemistry and form factor that do not leak.

Rechargeable lithium-ion batteries are not a new technology. Sony began marketing commercial lithium-ion batteries to the public over 30 years ago. Over the past decade, use of lithium-ion batteries for electrical grid application has become more widespread as lithium-ion batteries energy storage systems have been increasingly economically viable.

Several local, state, national and other applicable building, safety, and fire codes are applicable to the design, construction and operation of the North Bay Energy Storage Project, including:

• Sonoma County Building, Development, and Fire Codes
• California Fire Code
• National Electric Code
• National Fire Protection Association (NFPA) Standards
• Underwriters Laboratories (UL) Certifications
• International Electrotechnical Commission Standards

These codes are constantly being updated to improve safety and keep up with changes in the industry. Modern, lithium-ion battery energy storage systems are subject to robust testing and detailed safety standards from recognized authorities such as the NFPA and UL. The most notable standard is UL 9540, which requires compliance with several related codes and analyzes safety of battery energy storage systems. In addition, compliance with NFPA 855 set forth minimum design and safety standards for battery energy storage systems.

The North Bay Energy Storage Project will employ several redundant safety systems, including:

• Cell and enclosure venting
• Fuses and circuit breakers
• Automated onsite battery management system monitoring hundreds of times per second
• 24/7/365 remote monitoring of hundreds of data points each second
• Smoke, heat and gas detection
• Fire protection/suppression system
• Layers of physical fire containment/separation and appropriate spacing between equipment
• First responder training during construction and annual training thereafter, at the Project Applicant’s sole expense
• Designated Project staff will be stationed in the nearby area will receive Project-specific disaster preparedness training when they are hired and annually thereafter
• Redundant ingress and egress for first responders

The North Bay Energy Storage Project is very likely to use lithium-iron phosphate (LFP or LFP4) chemistry, which is different from cobalt-based lithium-ion battery chemistries that are common in electric vehicles and first-generation BESS systems. LFP has both a higher thermal runaway onset temperature and a higher state of charge tolerance, all of which equates to a battery that can safely handle higher temperatures.

Similar to all electric utility infrastructure in seismically-active California, including the adjacent PG&E Lakeville substation, the North Bay Energy Storage Project will be subject to ground shaking in the event of an earthquake. The battery enclosures will sit on concrete foundations designed pursuant to the latest applicable California Building Codes requirements, including those standards related to seismic-loading. The battery enclosures will be seismically anchored to foundations, minimizing potential for the enclosures and their contents to shift during an earthquake. Safeguards such as an automated management system and circuit breakers are in-place to disconnect the system from the electrical grid if the system recognizes irregular movement.

In addition, applicable codes and standards require that battery components are subjected to extensive physical and electrical abuse testing before they can be installed onsite. As a result, even if the onsite battery are jostled and disturbed during an earthquake, testing conducted prior to onsite integration will ensure the integrity of battery cells, modules, rack, and enclosures while also assuring that the battery system behaves in a safe manner.

Construction of the BESS Facility is anticipated to occur over approximately 10 months.

At the end of its useful life, the North Bay Energy Storage Project will either be replaced or decommissioned. Decommissioning means removing all Project equipment and improvements from the Project site and restoring the site to pre-construction (or better) conditions.

Strata’s master supply agreements with battery manufactures typically address battery recycling obligations. The battery manufacturers Strata works with reclaim their lithium-ion batteries as many of the battery component parts can be recycled and used in new products. In addition to re-use in new battery cells, the recycled materials extracted can be used in a wide variety of consumer products such as lubricants and additives to building products.

The Use Permit application for the North Bay Energy Storage Project was submitted early 2022. In October 2022, the Project was preliminarily reviewed by the Sonoma County Design Review Committee (DRC). Currently, California Environmental Quality Act (CEQA) documents are being prepared. Once the CEQA documents are publicly circulated for review, a link to these documents will be provided on both this and the County’s websites. Once a Board of Supervisor hearing is scheduled for the Project, notice will also be provided on this and the County’s websites.

There will be several opportunities to provide comments on the North Bay Energy Storage Project:

• Open House
• CEQA public comment period
• Public Hearing