Why Interval Data Matters for California Solar and Battery Sizing
Your Electric Bill Only Tells Part of the Story
Your monthly electric bill tells us how much electricity your home used over the course of a billing cycle. What it doesn’t show us is when you used that energy.
That distinction matters when designing a solar and battery system in California.
Two homes could use the same amount of electricity each month but have completely different energy needs. One household may use most of its electricity while the sun is shining, while another may use much more energy in the evening after solar production drops.
Looking at your usage throughout the day gives us a much clearer picture of how solar and battery storage can work for your home.
What Is Interval Data?
Interval data is a detailed record of your home’s electricity usage throughout the day. Instead of showing only a monthly total, it breaks your usage into smaller time periods so we can see how your electricity needs change from morning to afternoon, evening and overnight.
For example, interval data can show us when:
- Your electricity usage typically increases
- Your solar panels would be producing energy
- Your evening energy usage begins to rise
- How much electricity your home uses overnight
This gives us a much better understanding of your actual energy habits than a monthly bill alone.
Why “When” You Use Energy Matters in California
Under California’s Net Billing Tariff and time-of-use rates, the value of electricity can change depending on when energy is produced, used or sent back to the grid.
That makes the timing of your energy usage especially important.
Solar panels produce most of their energy during daylight hours, but many homes use a significant amount of electricity later in the day and into the evening. A battery can store excess solar energy produced during the day so it can be used later, when your solar panels are producing less or no electricity.
Knowing when your home typically uses energy helps us understand how much of that evening and overnight usage may need to come from battery storage.
What Interval Data Tells Us That Monthly Usage Can’t
Two homes can use the exact same amount of electricity in a month and need very different solar and battery systems.
For example, one homeowner may use most of their electricity during the day, when their solar panels are producing. Another may use a large portion of their electricity between 4 p.m. and midnight, after solar production begins to fall. On a monthly utility statement, those homes can look almost identical.
Interval data shows us the difference.
It allows us to see how your electricity usage changes throughout the day, including when your usage increases, how much energy you typically need after sunset and how long your battery may need to power your home overnight.
That level of detail is especially valuable under California’s time-of-use rates. Rather than designing your system based only on how many kilowatt-hours you use each month, we can design it around when you actually use them.
Is One Battery Enough for Your Home?
There isn’t a one-size-fits-all answer.
We’re finding that many California homeowners need two batteries to adequately cover their evening and overnight energy usage, even when one battery may initially seem sufficient based on their total monthly consumption.
That’s where interval data makes a difference. By looking at when your home actually uses electricity, we can estimate how much stored energy you typically need after solar production ends and whether one battery is likely to make it through the night.
Our goal isn’t to sell you more battery capacity than you need. It’s to make sure the system we design can actually do what you expect it to do.
This is why having your interval data before your consultation is so valuable. It allows your Energy Consultant to discuss battery sizing based on your home’s real usage, not an assumption.
How Photon Brothers Uses Your Interval Data
Before your consultation, our team can review your interval data alongside your overall electricity usage and the other information we gather about your home.
This helps us better understand:
- How much electricity your home uses
- When you typically use the most energy
- How much energy you use after solar production ends
- How much battery storage may make sense for your usage
- How solar and battery storage can work together for your home
Instead of starting with a generic system size, your Energy Consultant can have a more informed conversation with you about a system designed around your actual energy usage.
Ready to Take the Next Step?
If we’ve requested access to your utility data, the process only takes a few minutes. Learn How to Authorize Access to Your Utility Data
Have questions about your solar or battery options? Our team is here to help.
