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California solar decisions
California solar cost calculator: check your bill and quote
This calculator checks a California solar quote against your own bill. Enter your monthly bill and, if you have a quote, its system size, cash price and remaining utility bill. It returns the price per watt, the yearly bill difference and a simple cash payback, with no contact details needed. It does not forecast production.
If you are still deciding whether solar is worth it, start with home solar cost and payback in California.
California Rate Relief is a private solar referral service.
Check the numbers in your bill and quote
Start with your electricity bill. If you have a quote, add its system size, cash price and remaining utility bill. Leave unknown values blank. After changing values, calculate again to update the optional inquiry.
What this tool can answer
It annualizes your bill, separates solar price per watt from battery cost and checks a quoted remaining utility bill against what you currently pay. It does not select a system size or predict rooftop production. Use the installer’s monthly production model and an address-specific assessment for that.
What each result means
- Current annual electricity bill
- Your monthly bill times 12. Use a 12-month average, not a summer bill, if your bill swings by season.
- Bill average per kWh
- Your annual bill divided by your annual usage. It includes fixed charges, so it runs above the energy rate on your plan. On PG&E, for example, the monthly Base Services Charge of about $24 for most customers “is not eligible to be offset by monthly generation credits” (PG&E). Solar will not remove charges like that.
- Solar-only price per watt
- The solar cash price divided by the system size in watts (DC). It is the fairest way to compare two quotes for different sizes. A battery is left out on purpose.
- Annual bill difference
- Today’s annual bill minus the annual utility bill the quote says you will still pay. It is not a savings figure until you subtract any loan, lease or PPA payment.
- Simple cash payback
- The cash price divided by the annual bill difference, in years. It leaves out upkeep such as replacing an inverter. A fuller method is in the California solar payback period guide.
Where to find each number
- Monthly bill and annual usage. Your utility bill or online account. Twelve months of usage is better than one.
- Quoted solar size, cash price and remaining bill. The state disclosure package. The CPUC says it includes “the total cost of the system, a one-year bill savings estimate, and the three-day right to cancel (five if the customer is over 65 years old),” and that it must be given to you before a contract is signed (CPUC, checked September 23, 2026). Ask for the cash price even if you plan to finance.
- Battery price. Only if the quote lists it separately. If the battery is bundled, ask for it on its own line.
Is your price per watt reasonable?
Compare it with what installers actually charge. Berkeley Lab’s August 2026 data update, which covers host-owned systems installed in 2025, found median prices among the 100 largest residential installers ranging from $2.4 to $6.3 per watt. Roughly 60% had medians below $4 per watt, almost 25% below $3, and about 10% above $5. Installed price there means the price before incentives, including any loan fees the installer passes through. Pairing solar with a battery raised the median by $2.1 per watt of solar among cash-purchase systems (Berkeley Lab, U.S. Distributed Solar and Storage 2026 Data Update, checked September 23, 2026).
Those are national figures. For California’s own median and how system size moves the total, see solar panel cost and sizing in California; for city permit fees and utilities, see the California solar cost index.
Why there is no rebate field
You may be looking for a California solar rebate calculator, but for most homes in 2026 there is little to subtract. The IRS says the homeowner credit “is not available for any property placed in service after December 31, 2025” (IRS). The state’s SGIP program pays toward batteries, not panels, and on September 23, 2026 its tracker showed most residential categories closed.
If you do have a written reservation, such as a municipal battery incentive, subtract it from the cash price before you enter it. Do not subtract an incentive a salesperson has only mentioned. What remains by utility is in solar rebates by California utility, and the state picture in California solar incentives in 2026.
Getting a solar estimate for your roof
This tool checks a quote; it does not predict what your roof will produce. For that you need an address-specific production model. PG&E customers can use PG&E’s Clean Energy Calculator, which uses “your household’s past 12 months of energy usage” and shows “product and installation costs, break even points, available incentives” (PG&E). How it compares with this tool is in the PG&E solar calculator guide. For system size, see how big a solar system you need; for how to pay, compare cash, loan, lease and PPA.
Solar cost calculator questions
How much does solar cost in California?
Price per watt times system size, before any incentive. Berkeley Lab’s 2026 data update found median prices among the 100 largest U.S. residential installers ranging from $2.4 to $6.3 per watt, with roughly 60% below $4 per watt. Enter your quote’s cash price and size above to see where it falls, and see the California cost guide for the state median.
Is there a California solar rebate calculator?
There is little left to calculate for most homes. The federal homeowner credit is not available for systems placed in service after December 31, 2025, and the state’s SGIP battery incentives were mostly closed on September 23, 2026. If you hold a written rebate reservation, subtract it from the cash price before you enter it.
How accurate is an online solar calculator?
Only as accurate as its inputs. This one does arithmetic on the numbers you enter and does not model production. For an estimate of what a roof will produce, use the installer’s monthly production model for your address; PG&E customers can also use the Clean Energy Calculator in their online account, which uses 12 months of their own usage.
What does simple payback leave out?
Financing costs, maintenance, equipment replacement, panel degradation, future rate changes and any incentive. It is the cash price divided by the first-year bill difference, so treat it as a quick screen, not a forecast.
Put the quotes on the same basis
A smaller monthly payment can hide a longer contract, less equipment or a larger remaining electric bill. Ask each bidder to fill the same gaps.
| Compare | Get it in writing |
|---|---|
| System and output | Same DC system size, module/inverter models and roof layout; monthly production with shading and losses shown. |
| Battery and backup | Usable kWh, continuous output, backed-up circuits, reserve setting and expected replacement costs. |
| Price and scope | Separate solar, battery, roof, panel upgrade, permits and interconnection. Compare cash prices before financing. |
| Utility bill | Same usage history and tariff; separate onsite use, grid imports, export credits and remaining fixed/delivery charges. |
| Contract and service | Who installs and who services it; written coverage by address, insurance, license record, exclusions and warranty claim process. |
| Payment and transfer | Cash, loan, lease or PPA; upfront costs, APR or escalator, total payments, home-sale and end-of-term terms. |
Want to discuss your solar options?
Start with the utility on your bill and what you pay in a typical month. Contact details come after that. California Rate Relief collects the information for a solar referral; the provider confirms availability, design and price.
California Rate Relief is a referral service. We are not a licensed contractor. California Rate Relief is compensated by a solar provider when a homeowner we refer signs an agreement. How we make money
Before you send anything
- What this is
- California Rate Relief is a private referral service. It is not a contractor, does not install or finance anything, and is not a utility, a government agency or an assistance program.
- What happens after the form
- Your project details are recorded for referral to a solar provider. The provider decides whether it can help and what it can offer; availability, design and price are determined after its own review.
- How you are contacted
- Read the consent wording before submitting. Your inquiry includes contact details for follow-up about the project; a provider decides whether it can serve it.
- Using the site without submitting
- The calculators, bill comparisons and checklists on this site work without contact details, and nothing on this page requires a submission.