Cost of Solar Panels in California 2026: NEM 3.0 Changes the Math

California solar averages $2.52 per watt before incentives on the EnergySage marketplace (state table, checked October 2026), so a 6kW system is about $15,120. The big shift since 2023: for PG&E, SCE and SDG&E customers the Net Billing Tariff (NEM 3.0) credits exports at hourly avoided-cost values instead of the retail rate, so the value of a system now depends on how much of its output you use yourself, and a battery is worth pricing on almost every quote. Policy detail from CPUC decisions.

California Cost by System Size

System size	At $2.52/W	+ Powerwall 3 at $13,473
5 kW	$12,600	$26,073
6 kW	$15,120	$28,593
7 kW	$17,640	$31,113
8 kW	$20,160	$33,633
10 kW	$25,200	$38,673
12 kW	$30,240	$43,713

Rows are system size times EnergySage's $2.52/W California average, before incentives. The battery column adds EnergySage's typical all-in Powerwall 3 installed cost of $13,473 (national marketplace quotes, May 2026). SGIP rebate not deducted; subtract it if you qualify (the rate depends on your budget and its current step).

NEM 3.0 in Plain Language

Before April 2023, California's investor-owned utilities ran net energy metering (NEM 2.0): a kWh exported to the grid earned close to the retail rate, so the meter effectively ran backwards and it mattered little when the panels produced.

The Net Billing Tariff (CPUC Decision D.22-12-056) applies to interconnection applications filed on or after 15 April 2023. Exports are credited at values from the CPUC's Avoided Cost Calculator, which change by hour and month and are well below the retail price for most hours. Energy your home uses at the moment the panels produce it still offsets the full retail rate, which in California averaged 29.75 cents per kWh in August 2026 against 18.16 cents for the US (EIA Electric Power Monthly, Table 5.6.A).

The practical effect: a solar-only system that exports most of its midday output is worth much less than it was under NEM 2.0, while a system sized to what you use in daylight hours, or paired with a battery, keeps more of its value. Systems approved under NEM 1.0 or 2.0 keep their tariff for the legacy period the CPUC set, so this applies to new applications.

Why Adding a Battery Restores the Math

A battery stores midday output that would otherwise be exported for a low credit and discharges it in the evening, when you would otherwise import at the retail rate (and, on time-of-use plans, at the peak rate). A Tesla Powerwall 3 holds 13.5 kWh, enough to cover a typical evening for many homes. It also provides backup during outages, including Public Safety Power Shutoff events.

The numbers depend on your tariff and your evening use, so do not accept a generic payback. Ask each installer for an hourly savings model on your actual rate plan, once for solar only and once with the battery, and compare the extra saving with the extra cost (the table above uses EnergySage's $13,473 typical Powerwall 3 cost; SGIP can reduce it).

Municipal Utility Customers: NEM 3.0 Doesn't Apply

The Net Billing Tariff covers the CPUC-regulated investor-owned utilities: PG&E, SCE and SDG&E. Municipal utilities such as SMUD (Sacramento) and LADWP (Los Angeles) set their own solar and export rules, which differ from each other and from the NBT, so check your own utility's current solar tariff before sizing a system or deciding on a battery.

Community Choice Aggregators (for example SVCE or EBCE) supply generation inside an IOU's territory; the IOU's Net Billing Tariff still applies, and the CCA may add its own export credit, so ask the CCA as well.

The 1 January 2027 Property-Tax Deadline

Revenue and Taxation Code section 73 keeps a newly installed active solar energy system, storage included, out of your property-tax reassessment. Under current law that exclusion becomes inoperative on 1 January 2027; a system that qualifies before then stays excluded until the property changes ownership (Board of Equalization analysis of SB 710). A bill to extend it, AB 2389, was held in committee in May 2026. If you are installing late in 2026, ask your county assessor how completion dates are treated.

California Permitting and Inspection

Many California cities and counties now issue residential solar permits through automated platforms such as SolarAPP+, which can approve a code-compliant design immediately instead of after manual plan review. Ask your installer whether your jurisdiction uses one, and expect utility interconnection approval to be a separate step after the permit and inspection.

Frequently Asked Questions

How much do solar panels cost in California in 2026?

EnergySage puts the California average at $2.52 per watt before incentives (state table, checked October 2026, from quotes on its marketplace), slightly below its $2.60 national average. At that rate a 6kW system is about $15,120. The 30% federal credit ended for systems placed in service after 31 December 2025, so that is close to what a 2026 cash buyer pays before any battery or SGIP rebate.

What is NEM 3.0 and how did it change solar economics?

NEM 3.0 is the Net Billing Tariff adopted by the CPUC in Decision D.22-12-056. It applies to PG&E, SCE and SDG&E customers whose interconnection applications were filed on or after 15 April 2023. Instead of crediting exports at the retail rate, as net metering did, it credits them at values from the CPUC's Avoided Cost Calculator, which vary by hour and month and are far below the retail price most of the time. Energy your home uses directly still offsets the full retail rate, so under NEM 3.0 the value of a system depends on how much of its output you use yourself.

Should I add a battery in California?

For most new installs on PG&E, SCE or SDG&E it is worth pricing one. Under the Net Billing Tariff, midday surplus exported to the grid earns a low export credit, while a battery can store it and offset evening imports at the retail rate. Whether the battery pays for itself depends on your rate plan and evening use, so ask installers to quote the same system with and without storage on your tariff. California's SGIP can reduce the cost: the Residential Solar and Storage Equity budget pays $1,100 per kWh of storage paired with solar for eligible low-income households; general-market rates are lower and step down by budget step.

What's the payback on California solar plus battery in 2026?

There is no single figure, because it depends on your utility, rate plan and how much of the output you use yourself. A worked upper bound for solar alone: if every kWh a system makes replaced grid power at California's August 2026 residential average of 29.75 cents (EIA), each 1,000 kWh would be worth $297.50. Exports under NEM 3.0 earn much less than that, so real savings are lower. Use your installer's hourly model on your own tariff, with and without a battery, and divide the net price by the modelled saving.

Does California still have the solar property tax exclusion?

Yes, but it has a deadline. Revenue and Taxation Code section 73 excludes a newly constructed active solar energy system, including its storage devices, from property-tax reassessment. Under current law the exclusion becomes inoperative on 1 January 2027; a system that qualifies before then stays excluded until the property changes ownership (Board of Equalization analysis of SB 710). AB 2389, a 2026 bill to extend it, was held in committee in May 2026. If the exclusion matters to you, confirm the timing with your county assessor before you sign.

What's the Self-Generation Incentive Program (SGIP)?

SGIP is a California Public Utilities Commission program providing upfront rebates for battery storage (and other distributed energy resources). The Residential Solar and Storage Equity budget ($280 million authorised) pays $1,100 per kWh of storage and $3,100 per kW of solar for eligible low-income households, with reservations open since 2 June 2025 (CPUC). General-market residential storage rates step down as each budget step fills; the current step is published on the SGIP step tracker at selfgenca.com. SGIP funds are administered through your utility (PG&E, SCE, SDG&E, SoCalGas). Funds are capped per program cycle and have run out mid-cycle in some past years.

Is CA Title 24 solar mandate still in effect for new construction?

Yes. The 2019 California Title 24 Building Energy Efficiency Standards (in force since 1 January 2020) require solar PV on most new single-family homes. The 2022 update (in force since 1 January 2023) extended solar requirements to most new multi-family homes and several commercial building types. Because the system is designed and permitted with the house, a new-construction install avoids a separate roof job. See the new-construction page for details.