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Single Family Grid Integration

Measure Description

The grid integration measure is a cross-cutting measure with relevance for single family, multifamily, and nonresidential market sectors. This report focuses on single family applications but includes some discussion of how the measures might be affected when applied to other market sectors. Single family targeted applications include batteries, heat pump water heater (HPWH) load shifting, heating, ventilation, and air conditioning (HVAC) load shifting, and home energy management systems (HEMS). These proposed submeasures were all developed as compliance options for the residential sector. Compliance options differ from mandatory or prescriptive requirements in that they represent an alternative approach for achieving compliance with the Title 24, Part 6 energy standards as a means to increase compliance flexibility. These submeasures would impact the Total Energy Design Rating (EDR) which would provide credits for reducing photovoltaic system sizing but would not be available for tradeoff against building energy efficiency measures.

Battery Storage Systems

The main code change proposals include the inclusion of standalone storage, battery control strategy updates and software enhancements. Adding a standalone storage compliance option would expand the compliance credit to non-solar PV paired battery systems and would adapt battery control strategies for standalone storage operation. The “Time of Use” (TOU) operational control strategy would be updated to more closely align with utility TOU periods and to minimize TDV costs (Pacific Gas and Electric 2020, San Diego Gas and Electric 2020, Southern California Edison 2020). To improve the battery control strategy compliance verification process, thorough definitions of each control strategy would be added to the battery compliance form. A Round Trip Efficiency (RTE) user input option would be added in the CBECC-Res compliance software to more easily define performance. CBECC-Res would enforce the JA12 minimum RTE requirement by not providing a compliance credit for non-JA12 compliant battery storage systems. A new safety standard would be referenced to align with updated industry safety standards, and interconnection and enforcement sections in JA12 would be updated with clarifying language. Battery ready buildings would be added as an alternative compliance pathway to minimum solar zone area requirements. These proposed changes would apply to the battery storage system compliance option, and affect new construction, additions, and alterations in the single family residential sector.

HPWH Load Shifting

In July of 2020, the Energy Commission approved a compliance credit for LSHPWHs by adopting Joint Appendix JA13 (Qualification Requirements for Heat Pump Water Heater Demand Management Systems). The Energy Commission had previously opened a docket for JA13 in October 2019 and in June 2020 uploaded a final draft version of JA13 (California Energy Commission 2020b) for approval. The proposed 2022 LSHPWH submeasure is planning to expand the magnitude of the recently adopted compliance credit by recognizing increased benefits associated with a Load Up strategy whereby additional energy is stored in the HPWH tank in advance of the utility peak period. This new approach is being called the Basic Plus Load Up strategy. To maximize compliance flexibility, three configurations of the Basic Plus measure are proposed: Basic Plus-1 would involve onboard control logic to control tank overheating during favorable time of use operating periods, Basic Plus-2 would credit larger volume HPWHs due to increased thermal storage capacity, and Basic Plus-3 would recognize the benefit of HPWHs with storage tank temperatures maintained at least 10°F above the default water heater set point temperature.

This submeasure would remain a compliance option and would apply to residential scale HPWHs installed in single and multifamily buildings, with applicability in new buildings, additions and alterations.

HVAC Load Shifting

The pre-cooling measure would modify the compliance option that gives Demand Flexibility credit for installation and proper programming of a Pre-Cooling Thermostat (PCT). It would be offered for newly constructed single family residential buildings only in Climate Zones 9-15. No updates to software are proposed, other than changing the setpoint assumptions for calculating the credit. The proposed measure is simpler and can be implemented with a non-communicating thermostat, programmed to optimize operation to minimize costs under a TOU rate schedule, by defining a pre-cooling schedule and a “no-cooling” schedule.

Home Energy Management

This submeasure clarifies the current exception to the solar zone credit when a HEMS is installed in combination with a smart thermostat, by defining specific qualifying criteria that must be met. This change revises an alternative to the mandatory requirement for minimum solar zone area defined in Section 110.10(b)1A. Exception 6 currently allows home automation systems to qualify if they include demand response capabilities and the ability to control lighting and appliances. However, the specific functions that constitute these capabilities are not defined with enough specificity to estimate energy and peak load savings, or to verify that the desired capabilities are present in specific applications. In addition, the term “home automation systems” is a general term that can apply to systems that primarily provide convenience or home security functions. The proposed change would replace “home automation” with “home energy management”, which is the more common term of art used in the industry for systems that provide energy savings capabilities, and would require compliance with ENERGY STAR® SHEMS eligibility criteria and compatibility with other demand response technologies qualified under Title 24, Part 6. This submeasure would apply only to new construction, and to both single family and multifamily residential buildings.

Relevant Documents

Measure proposals, supporting documents, and other outside references will be made public as they become available.

Round Two Utility-Sponsored Stakeholder Meeting Materials

Round One Utility-Sponsored Stakeholder Meeting Materials

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Final CASE Report Now Available

This measure description will be updated as research is developed to support the 2022 code cycle. For questions or suggestions, email Include the measure name in the subject line.


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The Statewide CASE Team values input from all stakeholders engaged in the Title 24, Part 6 code change process. We encourage the open exchange of code change comments and concerns.

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