Published May 30, 2026 · Updated June 1, 2026 · 5 min read
The short answer
California's big utilities bill on time-of-use rates, charging the most during the 4–9 PM peak when solar production is low. A solar-plus-battery system charges midday on cheap solar and discharges during peak, so you avoid your highest-cost grid power — the core savings strategy under NEM 3.0.
By Vinnie Curcie, Founder & CEO
What time-of-use pricing means
On a time-of-use (TOU) rate plan, the price of a kilowatt-hour changes by time of day. California's investor-owned utilities — PG&E, SCE, and SDG&E — set their most expensive 'peak' window in the evening, commonly around 4–9 PM, with cheaper off-peak rates overnight and midday. The catch: peak is exactly when the sun is low and your panels produce the least.
Why TOU plus NEM 3.0 makes a battery essential
TOU and NEM 3.0 compound each other. Daytime solar you export earns a low credit, while evening power you buy costs the most. A battery bridges that gap: it banks your midday solar and releases it during the 4–9 PM peak so you're not buying expensive grid energy when you cook dinner, run the AC, and charge the car.
A day in the life of a well-designed system
Morning: your panels wake up and start covering the house. Midday: panels overproduce, topping off your battery. Late afternoon into evening: the 4–9 PM peak hits, the battery discharges to power your home, and you draw little or nothing from the grid at its priciest. Overnight: if needed, you backfill from cheaper off-peak rates. That daily rhythm is what produces real savings under current rules.
Designing for your specific rate and usage
Different TOU plans have different peak windows and price spreads, and your savings depend on matching the system to your plan and habits — when you're home, your EV charging schedule, AC use. We read your utility bill and usage data to size the array and battery for your actual rate plan, rather than a generic template, so the system is tuned to beat the peak you actually pay.
FAQ
It's a utility pricing structure where electricity costs more at certain times of day. California's big utilities set their most expensive peak window in the evening, commonly 4–9 PM, with cheaper rates overnight and midday.
Incentives and rates change. This page is kept current — but always confirm specifics for your home.
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