What decides the answer in California
Since April 15, 2023, new PG&E, SCE and SDG&E solar customers who apply to interconnect take service on the net billing tariff (NBT) adopted in Decision 22-12-056; the utilities call it the “Solar Billing Plan”. The decision replaces retail-rate credit for exported energy with Avoided Cost Calculator values that vary according to grid needs. CPUC says these export credits are usually lower than the retail rate but can rise above it on late summer evenings. CPUC's net billing page covers the three large investor-owned utilities only; LADWP and other publicly owned utilities are outside it, and their customer-generation terms were not reviewed here. [1] [2]
Three NBT terms decide the arithmetic. First, the import price: NBT customers must take an electrification time-of-use rate, E-ELEC at PG&E, TOU-D-PRIME at SCE and EV-TOU-5 at SDG&E. PG&E's E-ELEC energy prices effective June 1, 2026 run from 28.468 cents/kWh (winter off-peak) to 55.214 cents (summer peak: 4 to 9 p.m. every day, June through September), plus a daily base services charge set by income tier (79.343 cents a day for households outside the two lower tiers). Second, PG&E and SCE residential customers who apply before the end of 2027 get a small export adder for nine years; SDG&E customers and homes required to add solar by the building code do not. PG&E's schedule sets that adder at 0.880 cents/kWh for 2026 applications and 0.440 cents for 2027. Third, PG&E applicants through December 31, 2027 lock a nine-year schedule of hourly export values, and the original customer keeps the NBT for a nine-year legacy period. SCE's and SDG&E's own rate sheets were not reviewed here. [1] [3] [4]
CPUC says NBT customers can maximize bill savings by pairing a battery with solar, so stored energy can be used or exported in those high-value hours. A battery also adds capital cost and round-trip losses. The storage row below raises the assumed self-use share, subtracts an assumed 10% round-trip loss (90% round-trip efficiency) on the stored energy and adds an assumed battery cost; it is not a battery dispatch simulation and omits cycling limits, replacement and outage value, so a battery is not automatically the economic winner. [1]
CPUC's SGIP page lists one residential budget that is not marked “available through 2025”: the Residential Solar and Storage Equity budget, reservable from June 2, 2025 and “Available to any low-income residential electric and/or gas customer in California”, at 1,100 dollars per kWh of storage and 3,100 dollars per kW of solar. The page does not say whether that budget is open today; it sends readers to the SGIP home page for whether a particular budget is open or closed. It also lists LADWP among the program administrators and points customers of other publicly owned utilities and co-ops to a program administrator list for this budget. This hypothetical household is not assumed to be low-income, so no SGIP amount is deducted; any rebate row below is a labelled assumption, not an SGIP estimate. Ask for your utility's hourly export values for your application year, the installer’s hourly production and battery dispatch estimate, and a cash price that includes the battery if one is proposed. [5]
How California pays for an exported kilowatt-hour
Export value differs from the full retail bill. The reference table is a common retail-value benchmark. New NBT customers do not receive retail value for exports; CPUC says their export credits are usually lower than the retail rate, so that benchmark usually overstates the value of their exports. An annual import/export split shows the direction of the gap but cannot capture hourly export values or a time-of-use battery strategy.
No federal residential credit is applied by default in any calculator or state benchmark on this site (Section 25D expired at the end of 2025), and the mechanics of export regimes are covered in the net metering guide.
Sources for the California section above
- CPUC — net energy metering and net billing — NBT start date, IOU scope, required TOU rates per utility, PG&E/SCE adder window and legacy period.
Document: Net Billing section: export compensation adder, required TOU rates, nine-year legacy period. Effective/source period: NBT applies to interconnection applications from April 15, 2023; page retrieved September 24, 2026.
Applies to: Residential customers of PG&E, SCE and SDG&E; not publicly owned utilities. Relevant passage: “Since April 15, 2023, customers applying for interconnection have taken service on the new net billing tariff (NBT) pursuant to D.22-12-056”.
- CPUC Decision 22-12-056 — Avoided-cost, grid-need-based export valuation.
Document: D.22-12-056 (R.20-08-020), Decision Revising Net Energy Metering Tariff and Subtariffs, Summary, p. 3. Effective/source period: Dated December 15, 2022; issued December 19, 2022.
Applies to: Successor-tariff customers of PG&E, SCE and SDG&E. Relevant passage: “The successor tariff also replaces retail rate compensation for exported energy with Avoided Cost Calculator values that vary according to grid needs”.
- PG&E Electric Schedule NBT — Hourly export credit method, nine-year lock-in for applications through 2027 and the residential adder table.
Document: Electric Schedule NBT, Sheets 1 and 9–11. Effective/source period: Sheet 1 August 28, 2026 (Advice 7975-E); Sheet 9 October 17, 2025; Sheets 10–11 July 1, 2024.
Applies to: PG&E NBT customers; residential NBT customers must take Schedule E-ELEC. Relevant passage: “To determine the “Export Credit”, exported electricity will be multiplied by the hourly avoided costs values calculated by the Avoided Cost Calculator (Export Compensation Rates)”.
- PG&E Electric Schedule E-ELEC — Required NBT import rate, its peak/off-peak energy prices and base services charge.
Document: Electric Schedule E-ELEC, Sheet 1 applicability, Sheet 2 total bundled rates, Sheet 4 time periods. Effective/source period: Rates effective June 1, 2026 (Advice 7921-E, D.26-04-036); time periods effective March 1, 2026.
Applies to: PG&E residential customers; required for residential NBT customers. Relevant passage: “Residential customers billed on the Net Billing Tariff must be served under this schedule and are not required to have any of the eligible technologies listed above”.
- CPUC — SGIP — Currently listed residential SGIP route, its income eligibility and published incentive rates; not proof of this scenario's eligibility.
Document: Self-Generation Incentive Program page, budget table. Effective/source period: Residential Solar and Storage Equity reservations from June 2, 2025; page retrieved September 24, 2026; no household reservation verified.
Applies to: Low-income residential electric and/or gas customers for the Equity budget, including publicly owned utility and co-op customers through a listed program administrator; other budgets carry their own restrictions. Relevant passage: “Available to any low-income residential electric and/or gas customer in California”.
“Source documents checked 2026-09-24” means each linked document was retrieved on that date and the passage quoted under it is the text the claims in this section rely on. The date covers only those claims. It is not a household eligibility decision or a guarantee that a tariff is still current, so check the linked live documents before signing a contract, and report corrections via the contact page.
Reproduce the California household comparisons
These are hypothetical households, not customer results or offers. All start from an assumed 7 kW array producing 12316.12 kWh in year one; any row that changes production (a battery or a production-stress row) says so. The sunlight input is NSRDB data via PVWatts v8 for one location per state (request and response in state-insolation-pvwatts.json; see the methodology), not a production estimate for your roof. No federal credit is applied. No loan, income-tax effect on incentive revenue, battery replacement or future tariff change is modeled.
The benchmark row prices every kWh at the EIA average cited above. Where another row applies a published figure (for example a tariff or rider rate or charge, a program incentive rate, a statutory fee schedule, or a tax credit's rate, cap or carryforward period), that figure comes from a document in the sources list above. Every other price, consumption share, cost, fee, receipt date and amount of tax a household can use in a year is assumed. Eligibility remains conditional. The annual split does not reproduce monthly netting, time-of-use periods, credit caps, curtailment or minimum bills. Annual fees represent incremental solar costs, not charges you would pay with or without solar.
Production degrades by assumed 0.5% per year. The main result increases both import and export prices by assumed 3% per year; the flat-price column sets that to zero. Neither escalation is a tariff forecast. Fixed fees and scheduled receipts do not escalate. Energy savings accrue uniformly within a year for interpolation; incentives arrive only at year end.
Download exact scenario inputs and all 25 yearly results (JSON)Modeled results, not guarantees. No break-even means no crossing inside 25 years, not a calculated date beyond year 25.| Scenario | Initial cash cost | Year 1 energy value | Year 1 net cash incl. receipts | Payback | Flat-price payback | 25-year net cash after cost |
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| Common retail-value benchmark — no incentives | $22,400.00 | $3,937.46 | $3,937.46 | 5.4 years | 5.8 years | Modeled $111,833.98 |
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| Hypothetical household — no incentives | $22,400.00 | $2,167.64 | $2,167.64 | 9.3 years | 10.6 years | Modeled $51,497.97 |
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| Illustrative battery: assumed cost and higher self-use — no incentives | $32,400.00 | $3,295.04 | $3,295.04 | 8.9 years | 10.1 years | Modeled $79,932.66 |
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| Illustrative 75% self-use — no incentives | $22,400.00 | $3,417.72 | $3,417.72 | 6.1 years | 6.6 years | Modeled $94,115.26 |
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| PG&E E-ELEC lowest energy price for self-used solar — no incentives | $22,400.00 | $1,845.84 | $1,845.84 | 10.7 years | 12.5 years | Modeled $40,527.48 |
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| Illustrative 20% lower production — no incentives | $22,400.00 | $1,734.11 | $1,734.11 | 11.3 years | 13.3 years | Modeled $36,718.38 |
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| Illustrative 20% higher production — no incentives | $22,400.00 | $2,601.16 | $2,601.16 | 7.9 years | 8.8 years | Modeled $66,277.56 |
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Inputs, receipts and annual arithmetic: Common retail-value benchmark — no incentives
Historical state-average import value for ALL production; only a comparison, not an address-specific tariff.
Assumed initial cash cost $22,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 31.970¢/kWh; export 31.970¢/kWh; self-use 100%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 12316.12 × [(100/100 × 31.97/100) + ((1 − 100/100) × 31.97/100)] = $3,937.46. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Inputs, receipts and annual arithmetic: Hypothetical household — no incentives
Assumed annual import/export values, not CPUC hourly tariff prices or battery dispatch. The 35-cent import price sits inside PG&E E-ELEC's published June 1, 2026 range; the E-ELEC row below uses that schedule's lowest energy price. The 6-cent export price is an assumption: PG&E's hourly Export Compensation Rates were not fetched or annualised here.
Assumed initial cash cost $22,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 35.000¢/kWh; export 6.000¢/kWh; self-use 40%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 12316.12 × [(40/100 × 35/100) + ((1 − 40/100) × 6/100)] = $2,167.64. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Inputs, receipts and annual arithmetic: Illustrative battery: assumed cost and higher self-use — no incentives
Same 35-cent import and 6-cent export prices as the hypothetical household. No SGIP amount is included: CPUC's SGIP page lists the Residential Solar and Storage Equity budget as “Available to any low-income residential electric and/or gas customer in California”, at 1,100 dollars per kWh of storage; this household is not assumed to be low-income and no battery capacity is specified. The battery is assumed to store 35.90% of production that would otherwise be exported, so that 75% of the energy delivered is used at home instead of 40% of production. An ASSUMED 90% round-trip efficiency is applied to the stored energy: 3.59% of production is lost, so modeled first-year energy is 11874.00 kWh instead of 12316.12 kWh. The added storage cost of 10,000.00 dollars is an assumed sensitivity value, not a quote; with every other input unchanged, an added cost of 5,000.00 dollars gives 7.6 years (8.5 years at flat prices) and 15,000.00 dollars gives 10.1 years (11.7 years at flat prices). No dispatch schedule, time-of-use value, battery degradation, replacement or outage value is modeled.
Assumed initial cash cost $32,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 35.000¢/kWh; export 6.000¢/kWh; self-use 75%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 11874.00 × [(75/100 × 35/100) + ((1 − 75/100) × 6/100)] = $3,295.04. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Inputs, receipts and annual arithmetic: Illustrative 75% self-use — no incentives
Assumes a different load profile serves 75% of production on site without added equipment cost. This is a sensitivity, not a promised behavioral saving.
Assumed initial cash cost $22,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 35.000¢/kWh; export 6.000¢/kWh; self-use 75%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 12316.12 × [(75/100 × 35/100) + ((1 − 75/100) × 6/100)] = $3,417.72. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Inputs, receipts and annual arithmetic: PG&E E-ELEC lowest energy price for self-used solar — no incentives
PG&E Electric Schedule E-ELEC, rates effective June 1, 2026 (Advice 7921-E, D.26-04-036), lists total bundled energy prices from 28.468 cents/kWh (winter off-peak) to 55.214 cents (summer peak, 4 to 9 p.m.). CPUC names E-ELEC as the TOU rate PG&E net-billing customers must take (TOU-D-PRIME at SCE, EV-TOU-5 at SDG&E; those two schedules were not checked here). Much self-used solar output displaces daytime off-peak use, so this row values every self-used kWh at the schedule's lowest energy price, 28.468 cents, as a conservative bound. The daily base services charge is paid with or without solar and is left out. Exports keep the assumed 6 cents: NBT credits are hourly Avoided Cost Calculator values that are not reproduced here, and the PG&E/SCE export adder for applicants before the end of 2027 is not added. PG&E territory only.
Assumed initial cash cost $22,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 28.468¢/kWh; export 6.000¢/kWh; self-use 40%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 12316.12 × [(40/100 × 28.468/100) + ((1 − 40/100) × 6/100)] = $1,845.84. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Inputs, receipts and annual arithmetic: Illustrative 20% lower production — no incentives
Same prices, self-use share and cost as the hypothetical household, with first-year production 9852.90 kWh instead of 12316.12 kWh. Roof direction, shading and location within the state can move production by this much. At the same production the retail-value benchmark gives 6.6 years (7.2 years at flat prices).
Assumed initial cash cost $22,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 35.000¢/kWh; export 6.000¢/kWh; self-use 40%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 9852.90 × [(40/100 × 35/100) + ((1 − 40/100) × 6/100)] = $1,734.11. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Inputs, receipts and annual arithmetic: Illustrative 20% higher production — no incentives
Same prices, self-use share and cost as the hypothetical household, with first-year production 14779.35 kWh instead of 12316.12 kWh. Roof direction, shading and location within the state can move production by this much. At the same production the retail-value benchmark gives 4.5 years (4.8 years at flat prices).
Assumed initial cash cost $22,400.00, not reduced by any upfront credit or rebate; any receipt is listed below and arrives at year end. Import 35.000¢/kWh; export 6.000¢/kWh; self-use 40%; incremental fixed annual cost $0.00.
Year-one modeled energy value = 14779.35 × [(40/100 × 35/100) + ((1 − 40/100) × 6/100)] = $2,601.16. Subtract the annual fixed cost and add only that year's receipts for net cash. Display rounds cents; the downloadable calculation retains full precision.
Incentive basis: None; no eligibility or benefit assumed. Modeled total receipts inside 25 years: $0.00. These are not subtracted from initial cash cost.
The exact input fields and all 25 modelled years for this row are in the JSON download above.
Formula and modeling limitations · Use the editable calculator below to test your own cash price and energy split. It cannot confirm utility enrollment or tax eligibility.
Assumptions behind the California retail-value benchmark
A common full-retail comparison, not an address-specific forecast. Size alone does not change payback when cash cost and production both scale proportionally. Use the worksheet to vary cash price, production, self-consumption, export value and recurring costs.
- System modeled
- 7 kW DC
- Assumed installed cost
- $22,400 (assumed $3.20/W DC)
- Annual production, year 1
- 12,316 kWh
- Production basis
- NSRDB daily sunlight on a 20° south-facing panel at California's 2020 Census population center (6.18 kWh/m²/day, via PVWatts v8). Annual production = system kW × this input × 365 × assumed performance ratio. PVWatts' own modelled AC output for the same request is 1,679.4 kWh per kW, or 11,756 kWh for 7 kW, so this shortcut runs 4.8% above it; on the PVWatts figure the benchmark payback would be 5.6 years.
- Performance ratio (system losses)
- 0.78
- EIA state-average retail rate
- 31.97¢/kWh — Calendar year 2024 annual average
- Panel degradation
- 0.5%/yr
- Assumed electricity price escalation
- 3.0%/yr, not a forecast
- Model horizon
- 25 years
- Federal tax credit applied
- None included in this benchmark
- State or utility incentives applied
- None deducted in this benchmark. Where a household scenario above applies a published tariff rate or a conditional receipt, its row says so; this benchmark applies none of them
- Assumed value of all production
- Full retail rate, including exports; not a utility tariff lookup
- Recurring operating costs applied
- None in this benchmark; editable in worksheet
How the payback figure reconciles
- Modelled $22,400 ÷ modelled $3,937 of year-one savings = 5.7 years — the straight division, if electricity prices never move and the panels never age.
- With 0.5%/yr degradation and prices held flat: 5.8 years.
- With the same degradation and electricity prices rising 3.0%/yr: 5.4 years — the retail-value benchmark, not a household forecast.
- Production stress test, same assumed prices: 20% less production (shading, a poorer roof angle) gives 6.6 years; 20% more production gives 4.5 years. This is a what-if range, not a confidence interval.
These price-growth rates are assumptions, not forecasts of your utility's tariff. None of these cases models financing, taxes, battery dispatch or actual utility settlement. No crossing within 25 years does not establish a crossing later. Full wording on the methodology.
Estimate only. State comparisons are common retail-value benchmarks, not forecasts for your roof. Custom scenarios depend on the cash price, production, import/export prices, self-consumption and other assumptions entered. They are not quotes or guarantees. Listed incentives do not establish eligibility or a payment date. The Residential Clean Energy Credit (
Section 25D, the 30% federal tax credit) expired for systems placed in service after December 31, 2025. Verify all numbers with a licensed installer and your utility before making a purchase decision. See
full disclaimer.