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

Project Update

In 2024, the team conducted data analysis of currently installed systems, evaluating the capability and capacity of each the installed residential energy storage systems. As of February 2025, 11 commercially available residential lithium-ion batteries have been installed in Sonoma and San Diego Counties. Several additional installations are pending in homes located in the northern, central valley, and coastal climate zones.  Over 2025, the remaining 4 installations will be completed and measurement, verification, and data analysis will be performed.

The Issue

Recent updates to the Title 24 building code require solar PV on all new residential construction. As a result of more frequent grid outages from power safety power shutoffs (PSPS) and wildfire events, customers are expected to be more interested in adding energy storage to their homes for resilience. However, homeowners do not fully understand the value that they can achieve by having solar plus storage in the home.

Project Innovation

This project will install and connect energy storage units to 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 the systems to capture the best operational practices of the systems for the residents and the grid. The project will also provide insight that will help inform any future changes to Title 24 building code to help realize these values.

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

The project will assist in informing how to overcome barriers to implementing residential storage by providing recommendations derived from field demonstrations. The project will also help inform enhancements on Title 24 building code to better suit California's plans for decarbonizing the grid through more and better use of renewable generation. Potential new homes built in alignment with a better developed Title 24 building code favoring controllable energy storage could provide greater cost savings to homeowners and greater grid stability. This project will assess the operation of commercially available residential battery storage systems and intends to develop new use cases by exploring tariff structures, independent control strategies (such as helping to optimize residential energy use, particularly during the evening ramp), and cost considerations that provide maximum benefits to both the customer and the grid.

Lower Costs

Affordability

Connecting energy storage systems with mandated solar energy generation systems in new residential construction can result in reducing customer demand charges by appropriately controlling the generation and storage for the customers' loads particularly during periods of peak rates.

Greater Reliability

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.

Energy Security

Energy Security

In October 2019, public safety power shutoff events left nearly two million Californian utility customers without electricity during two separate weekends. Customers that only had solar PV were often unable to take advantage of renewable power. Adding energy storage and properly controlling the combination should ensure critical loads stay active during these types of events.

Key Project Members

Project Member

Herb Yaptinchay

Project Manager
EPRI
Project Member

Evan Giarta

Principal Investigator
EPRI

Subrecipients

Rocket

Abstractal LLC

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