The 2022 Building Energy Efficiency Standards (Energy Code) has battery storage system requirements for newly constructed nonresidential buildings that require a solar photovoltaic (solar PV) system (2022 Nonresidential Solar PV Fact Sheet).
The solar PV requirements apply to buildings where at least 80 percent of the total floor area (conditioned or not) is made up of building types listed in Table 140.10-B, including mixed occupancy buildings. These include:
- High-Rise multifamily
- Office, financial institutions, unleased tenant space
- Auditorium, convention center, hotel/motel, library, medical office building/clinic, restaurant, theater
These requirements do not apply to:
- Unconditioned buildings, except first-time tenant improvement spaces, as they meet the definition of newly constructed buildings
The required battery storage system size is based on the solar PV system size determined for building types listed in Table 140.10-B, including mixed-occupancy buildings.
Section 140.10(b) of the 2022 Energy Code has two equations to calculate the total battery capacity for building types listed in Table 140.10-B using the solar PV system size from Equation 140.10-A.
- Rated energy capacity (Equation 140.10-B), based on:
- Required solar PV system size
- Energy capacity factor
- Round-trip efficiency of the battery system
- Rated power capacity (Equation 140.10-C), based on:
- Required solar PV system size
- Power capacity factor
The total capacities of a battery storage system shall be no less than those calculated from the equations above. For mixed use buildings that contain the building types listed in Table 140.10-B, the capacities should be determined for each building type, including its support areas, then added together for the entire mixed use building.
The standard design battery storage system size is determined using the prescriptive solar PV size requirement for the proposed design, regardless of the fuel type. A battery storage system can be installed as a standalone system for additional compliance credit, when not required prescriptively. Also, a battery system larger than the prescriptive requirement can be used to tradeoff for a smaller solar PV system.
Yes. Four exceptions can exclude nonresidential buildings from the battery storage system requirements:
- If the installed solar PV system size is < 15 percent of the size calculated from Equation 140.10-A
- Buildings with battery storage system requirements < 10 kWh rated capacity
- Single-tenant buildings with < 5,000 square feet of conditioned floor area (CFA). For multi-tenant buildings, the battery storage system energy and power capacities are based on tenant spaces > 5,000 square feet of CFA
- Offices, schools, and warehouses in Climate Zone 1
NOTE: Solar PV requirements still apply when exempted from battery storage.
The installed battery must meet or exceed requirements in the 2022 Reference Joint Appendix JA12 and be manufacturer-certified to the California Energy Commission (CEC). A list of certified batteries is available on the CEC website.
The battery storage system must meet the minimum system performance requirements specified in Table 1 below, in addition to the following requirements:
- Control strategies,
- Interconnection and Net Energy Metering, and
- Verification of Certificate of Installations by the local enforcement agency
Table 1: Minimum Performance Requirements for Battery Storage Systems
|Battery Performance Specification
|Usable capacity > 5 kWh
|Single charge-discharge cycle AC to AC (round-trip) efficiency > 80%
|Energy capacity of 70% of nameplate capacity after 4,000 cycles
covered by warranty or 70% of nameplate capacity under 10-year warranty.