How the bill after solar is calculated: SCE NEM 3.0

Under the old net metering, a kWh sent to the grid was worth about as much as one taken from it. Under the Net Billing Tariff it’s worth far less at most hours, so when the home uses its own solar matters a lot.

Hour by hour

• Taken from the grid — paid at the full TOU-D-PRIME price of that hour.
• Sent to the grid — earns the export price for that hour, set by the CPUC’s avoided-cost tables and locked for 9 years from the year the system is turned on. Prices are highest on summer evenings and low at midday.
• The two aren’t netted against each other; Cali-Graf calculates both for every hour of the year.

Month by month and the true-up

• Each month, the export credit pays down the energy part of the bill; what’s left rolls forward. It doesn’t pay the daily basic charge, other fixed charges or taxes.
• Once a year, at the true-up, the energy for the year is settled. Unused export credit is lost.
• The yearly bill in the result includes the true-up. When it comes to a dollar or more, All numbers shows Annual true-up included: …

Clean Power Alliance customers

For CPA homes SCE bills the delivery and CPA the generation, each with its own export credit, carry-forward and true-up. The two credits don’t pay each other’s charges. Cali-Graf uses the city’s default CPA plan.

What it means for the design

The more solar the home uses as it’s made — and the more a battery moves to the 4–9 PM peak — the bigger the savings. How solar is used in All numbers shows Solar used by home and Home powered by solar. See Battery operating modes.