Demonstrating Code-compliant Energy Storage Systems and Their Capabilities for Grid Harmonization

Evaluates the effectiveness of energy storage in zero net energy ready homes in terms of managing customer costs, providing grid harmonization and reducing grid carbon when applied as per Title 24 and when applied in the mode that is standard for

Electric Power Research Institute, Inc.

Recipient

Palo Alto, CA

Recipient Location

13th

Senate District

23rd

Assembly District

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$405,336

Amount Spent

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Active

Project Status

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Project Update

In 2025 the team completed installations for all of the 15 required residential lithium-ion battery storage systems in three different California climate zones. Data collection and analysis have started and will continue through 2026, focused on evaluating the capability and capacity of each the installed residential energy storage systems as well as generating better understanding of how customers use these systems in the real-world.

The Issue

Recent updates to the Title 24 building code require solar PV and "energy storage ready" on all new residential construction. As a result of more frequent grid outages from power safety power shutoffs (PSPS) and wildfire events, customer interest in residential energy storage is growing for backup power applications. However, there is lack of data on the real-world performance of Title 24 compliant systems including how customers are using them. Additionally, customers themselves do not fully understand the value of solar-plus-storage in their home, which can limit potential future adoption.

Project Innovation

This project will install and interconnect energy storage units to homes with existing solar panels at a minimum of 15 Title 24 compliant single-family homes in three different California climate zones. The project will test and evaluate the control and operation of these storage systems to document their performance and to inform best operational practices for simultaneously providing benefits to the residents and to the grid. The project will also provide insight that may inform future changes to Title 24 building code to help realize these benefits.

Project Goals

Analyze different compliance pathways with and without energy storage to achieve T24 energy and efficiency requirements

Quantify impact coordinated operation of localized energy storage can provide to mitigate demand surges & benefit the grid

Report on potential areas of improvement of the current building code.

Further develop control and optimization strategies, as needed to improve grid harmonization of the building code.

Further inform on control & optimization strategies, as needed to improve grid harmonization of the building.

Project Benefits

This project will generate field data and improved understanding of how residential storage systems are being used and what factors such as installer settings, control modes, and site characteristics can increase customer and grid benefits to meet the intent of Title 24 and Joint Appendix 12. The lessons from this project can inform future Code updates while also providing near-term benefits such as reduced peak demand from demonstration of compliant residential storage technologies.

Affordability

Validating Title 24 compliant solar-plus-storage controls from different vendors helps build market offerings and customer awareness of these technologies, in turn promoting greater scale and lower costs. Upgrading existing residential solar generation with storage can reduce exports and optimize customer self-consumption which could reduce customer electricity bills.

Reliability

Controlling solar-plus-storage systems in new residential construction can result in maximizing solar energy generation during high generation, low demand hours that can reduce reliance on power plants needing to ramp up production to meet demand and relieve pressure on the stressed grid infrastructure.