General Information
The 2022 Energy Code now requires that all single-family buildings with one or two dwelling units must be energy storage (battery storage) system ready.
These requirements are mandatory but do not apply to:
- Additions
- Alterations
- Newly constructed buildings with all battery storage installed
To facilitate the future installation of battery storage systems, newly constructed single-family buildings with one or two dwelling units are required to be energy storage ready.
An energy storage system is defined in the 2022 Energy Code as one or more devices assembled together to store electrical energy and supply electrical energy to selected loads at a future time.
The requirements in Section 150.0(s) of the 2022 Energy Code include:
- Either:
- An ESS ready interconnection equipment with a minimum backed-up capacity of 60 amps and a minimum of four ESS-supplied branch circuits (See Figure 2); or
- A dedicated raceway at least 1 inch from the main service panel to a subpanel that supplies the branch circuits
- A minimum of four branch circuits and their source at a single panelboard supplied by the ESS. At least one circuit shall supply:
- Refrigerator,
- Lighting near primary egress, and
- Sleeping room receptacle outlet
- The main panelboard must have a minimum busbar rating of 225 amps
- A space reserved for a future installation of isolation equipment/transfer switch within 3 feet from the main panel
Frequently Asked Questions
Yes. The 2022 Energy Code ESS-ready requirements in § 150.0(s) - PDF apply to all single-family residences that include one or two dwelling units.
Yes. Duplexes are considered two single-family homes. Each duplex unit would have a separate panel with 225 amp busbar rating to meet the ESS-ready mandatory requirements in § 150.0(s) - PDF.
No. Per the definition in § 100.1 - PDF a townhouse is a single-family dwelling unit constructed in a group of three or more attached units. Townhouses do not need to meet the ESS-ready requirements in § 150.0(s) - PDF.
Yes. A newly constructed residential building that includes a dwelling unit of any size must meet the energy storage system ready requirements per § 150.0(s). The ADU must also meet the electric ready requirements in § 150.0(t)-(v) when installing gas appliances. (2022 Single-Family Electric-Ready Fact Sheet).
No. If the new residential building does not include a dwelling unit, such as a pool house, art studio, office, etc., it will not need to meet the ESS-ready requirements.
Yes. A 200 amp panel could meet the requirement if the busbar rating is 225 amps and it is clearly marked on the panel. However, if there is no specific busbar rating on the panel, the 200 -amp panel will not meet the requirement since the busbar rating will be the same as the panel rating. Panels must also meet applicable requirements in the California Electrical Code.
No. The subpanel to the ADU from the main panel could meet § 150.0(s)1B - PDF, as long as the main panel has the 225 amp busbar rating.
Yes. Per § 150.0(s)1A - PDF ESS-ready interconnection equipment is required to have a 60 amp backed- up capacity and a minimum of four ESS-supplied branch circuits. See Figure 3. Various configurations of panels and subpanels could meet the ESS-ready requirements of § 150.0(s) - PDF.
Yes. Per § 100.1 - PDF ESS-ready interconnection equipment is defined as equipment, including but not limited to an ESS-ready panelboard, that can accommodate the connection of a distributed energy resource or an ESS capable of either automatic or manual isolation from the utility power source. An ESS-ready panelboard is defined as a panelboard that can accommodate either automatic or manual switching between a utility power source to a distributed energy resource or an energy storage system, such as a split bus panelboard.
Yes. If the newly built home’s energy storage system meets all the necessary wiring and other electrical components required to support a fully operating energy storage system, this will satisfy the mandatory requirements in § 150.0(s) - PDF.
See the Blueprint for more information, including articles and frequently asked energy storage system ready questions, about the 2022 Energy Code.