If you’re an architect, new homebuilder or housing developer in California, you’ve probably heard by now that the California Energy Commission (CEC) has updated its Title 24 solar and energy efficiency standards. Effective January 1, 2020, the update specifically mandates that all new California homes under three stories install solar panels on the roof or achieve an equivalent total home energy efficiency reduction through other measures.
To comply with Title 24, new homebuilders, architects and developers will be required to use Title 24’ssoftware for calculating the building’s “Energy Design Rating” (EDR), which not only includes inputs for solar but also for energy storage and other options.
To give builders more flexibility, the EDR is scored like a golf tournament—the lower the score, the better (or, the more “energy efficient” the home is). The goal is to achieve an equal-to-or-less-than EDR for a solar home than a comparable “regular” home, of the same square footage.
Depending on the square footage and climate, new-home solar will range between 2.7 and 5.7 kW DC to meet the requirements, but that doesn’t tell the whole story. Rather than meeting the minimum requirements, builders may be better off designing their Title 24 solar systems with battery storage.
As mentioned, the EDR software gives homebuilders a score, but there are many ways to meet that score, and one is combining solar with energy storage. Including energy storage will not only meet the minimum solar requirements, but will maximize energy savings for the home, offering customers a financial advantage over other homes.
When solar engineers design a solar system, they typically take into consideration the following factors:
While these parameters are important, equally important are the utility rate considerations that system designers like SepiSolar factor into their plan sets. These rate policies affect the solar system’s ROI and include:
That’s where energy storage (batteries) comes in.
Due to the above utility rate considerations, home developers that want to design premium homes that maximize utility savings as well as comply with the Title 24 solar mandate should consider including energy storage systems with their solar designs.
Solar+storage with smart battery management software will counteract the cost of tiered rates and TOU through “load shifting,” and “peak shaving.”
With peak shaving, homes using solar+storage will be able to use as much free solar as they can during the highest TOU rates while saving the excess energy in their batteries instead of exporting to the grid. Then, during peak TOU periods, the home will use this free stored solar-generated energy when the utility rates are high.
Additionally, battery management systems can also “load shift” the time when appliances are turned on or off, such as turning on a dishwasher, dryer or charging an EV when utility rates are low or when electricity can be drawn from the battery that was charged by solar.
Both peak shaving and load shifting with solar+storage encourage the home to use more of its own self-generated power, relying less on importing power from the grid. With so many homes using solar after 2020, homeowners with solar+storage will also help stabilize the grid, and can be paid a higher credit for any power the utility draws from the storage system during peak hours.
Another sales advantage for developers is that solar+storage offers some emergency power in case of a blackout. That is not the case with stand-alone solar PV systems. To protect power line repair workers, stand-alone solar systems will automatically shut down during an outage.
If you decide to meet your Title 24 solar mandate with energy storage, there are several requirements to keep in mind.
First, when adding storage to solar, there is a minimum required battery size of 5 kWh. This is a reasonable size that will allow for taking advantage of tiered rates and TOU, and it will provide a minimal amount of backup power in case of an outage.
Second, your solar+storage system designer and engineer will have to select one of three control options for the battery:
The rules within each category will most likely be refined over time, so it’s important for your solar designer to be up to date with these standards and make any necessary changes. The above is a summary, so please review the entire Joint Appendix 12 to take full advantage of the above credits.
As longtime solar+storage engineers with thousands of projects, SepiSolar has a great deal of experience designing solar and battery systems that meet the new Title 24 regulations, as well as designing systems that comply with the local requirements of counties and other local authorities having jurisdiction (AHJs). Please contact us if you have any questions about these new Title 24 solar requirements for your new residential solar development projects.
