Ask ten homeowners what they pay for electricity and nine will tell you a monthly dollar amount. That's the bill, not the rate — and the rate is the number every solar estimate is actually built on.
Savings math is not complicated. It's roughly how much power your roof makes × what you'd otherwise have paid for that power. Get the second number wrong and everything downstream is wrong with it: the monthly savings, the payback period, the twenty-five-year figure on the last slide.
So it's worth knowing where your real rate hides.
Your rate is a range, not a number
Residential electricity in California is almost never sold at one flat price. Utilities file rate schedules, and most homeowners are on one of two shapes.
Tiered. You get a monthly allowance of cheap power — the "baseline" — and once you're past it, the price steps up. Two households on the same street with the same schedule can pay different average rates purely because one of them runs the air conditioning harder.
Time-of-use. Power costs different amounts at different hours. Cheap overnight, expensive in the late afternoon and evening when everyone gets home and the sun is going down. If you have an EV, a pool pump, or a thermostat you can schedule, this is usually where the interesting decisions live.
Both shapes also move by season. A schedule that looks like one flat price in March can be a different price in August.
That's why an honest estimate shows you a range and tells you which schedule it's reading — not a single tidy cent figure that appeared out of nowhere.
The line that catches people out
Here's the one that surprises even careful shoppers.
Some utilities — municipal ones especially — split the price of a kilowatt-hour into a base energy charge plus a separate adjustment. The adjustment covers things like energy cost recovery, subsidies and reliability programs. It is not a footnote. On some municipal schedules the adjustment is most of what you pay.
Take Los Angeles. In LADWP's filed residential schedule, the base energy charge is around seven cents per kilowatt-hour. Read only that line and you'd conclude Angelenos buy some of the cheapest power in the state. Add the adjustment and the real number lands near twenty-four cents — and LADWP's own published standard residential rate is right about there.
Same tariff. Same document. Three times the answer, depending on which line you read.
Investor-owned utilities like PG&E, SCE and SDG&E generally don't split it that way, so the base charge is closer to the whole story. But if you're served by a city utility and someone quotes you a suspiciously cheap rate, that's the tell.
How to find your actual number in sixty seconds
Skip all of it and go to the bill.
- Find the total amount you paid for the month — the full number, including every fee, charge and tax.
- Find the kilowatt-hours used that month. It's usually near the usage graph.
- Divide the first by the second.
That's your all-in effective rate, and it is the only rate that matters to you. It quietly includes the delivery charges, the fixed fees and the taxes that per-kWh quotes usually leave out.
Do it for a summer month and a winter month. The spread between those two is a better picture of your house than any single figure.
Why this decides whether solar pencils
If your all-in rate is 18¢ and someone builds you an estimate at 32¢, the savings number you're shown could be nearly double what you'd actually see. That's not necessarily anyone lying — utility rate data is genuinely messy, it changes several times a year, and plenty of tools are quietly reading a national average or a data set that's over a decade old.
It cuts the other way too. If your real rate is 38¢ because you're in a high tier every summer, a conservative estimate built on a state average is under selling what solar would do for you.
Either way, you can't evaluate the offer without the input.
What to ask before you sign anything
- Which rate schedule did you use, and what's its effective date? A real answer sounds like "PG&E E-1, effective March 2026." A vague one sounds like "about thirty cents."
- Tiered or time-of-use — and which am I on today?
- Does that rate include the adjustment and delivery charges?
- What escalation did you assume? Every twenty-five-year savings figure assumes utility rates keep rising by some percentage a year. Ask what percentage. A point or two of difference compounds into tens of thousands on the final slide.
- Which schedule would I be on after solar? Some utilities move you when you interconnect. This one gets skipped constantly.
A professional who can answer those five without flinching is worth listening to. One who can't isn't necessarily dishonest — but they're quoting you numbers they didn't check.
The short version
Your electricity rate isn't a number you know. It's a number you calculate, from the bill in your kitchen drawer, and it takes under a minute. Do that before you take a single estimate seriously — including ours.
