The focus of the nonresidential grid integration CASE Report is to adjust the demand response control requirements so buildings that comply with Title 24, Part 6 are more likely to use their controls to participate in demand response events, including pricing events. This will help ensure that newly constructed nonresidential buildings are contributing to grid reliability in a positive way, which is critical as California aims to achieve its renewable portfolio goals.
Add Alternative Control Strategies for Demand Response Controls for HVAC Systems (compressor cycling and pre-cooling)
Currently, demand response controls for HVAC must be capable of increasing or decreasing the temperature setpoints by four degrees. This requirement would remain in place, so at a minimum DR controls would still be required to enable temperature adjustments. This measure would modify the acceptance test requirements to allow the two additional g control strategies to be tested: compressor cycling and adaptive pre-cooling, and energy storage to enable load shifting.
This mix of alternative control strategies enables controls contractors to program the DR controls with the control strategy that the building occupant will actually use to participate in demand response programs at the time that the controls are installed thereby eliminating a need for reprogramming after the Title 24, Part 6 acceptance tests are complete. The additional control strategies shift electricity use across hours of the day and to decrease energy use on-peak or increase energy use off-peak. This will help alleviate the problem of oversupply of electricity during certain times of the day, and may even reduce the need for increased renewable generation in the future.
Compressor cycling in unitary HVAC systems will reduce energy use during a demand response event through three options:
- Turning off the compressor for 15, 20, or 30 minutes per hour,
- Locking out the second stage on the compressor, or;
- Reducing compressor speed on variable speed compressors.
All options still maintaining air flow for occupant comfort. Pre-cooling capability allows for a building to lower HVAC set-points for a limited amount of time to increase energy use off-peak and increase utilization of renewables. Buildings may also choose to use pre-cooling to harness the thermal mass of the building before initiating the demand response measure of increasing HVAC set-points to participate in longer demand response events with decreased occupant discomfort. Energy storage to enable load shifting, which includes thermal storage such as ice storage and battery storage, will enable a building to shift electricity use across hours of the day based on grid needs as electricity can be used to create ice or electricity can be decreased when ice is melted to support air conditioning.
Adjust DR Control Requirements for Lighting Systems in Response to Shift to Solid State Lighting.
The demand response control requirements for lighting systems were adopted before Title 24, Part 6 lighting power density requirements were based on LED technology. With a shift to LEDs, there are several changes that this submeasure will consider in demand response control requirements.
- Eliminate or adjust the exception that Demand Response Controls are not required if the lighting power density is 0.5 watts per square foot or less.
- Eliminate the requirement that general lighting must be reduced in a manner consistent with the uniform level of illumination (per Table 130.1-A).
Support Adding Compliance Options that Enable Load Shifting
The Statewide CASE Team will support efforts to add features to the compliance software that provide compliance credit for technologies and design solutions that enable load shifting. The specific compliance options that the Statewide CASE Team will support will be determined by Fall 2019, but they may include: battery storage, modifications to thermal energy storage algorithms, credit for DC circuitry when solar or battery systems are also installed on site, and heat pump water heating with grid connectivity.
Give Us Your Feedback
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.
Use the form above to provide feedback on this measure.