Data / Export rules
Export rules
What the utility pays for a kilowatt-hour you send out. Decides payback more than sunshine does.
- Records
- 13
- With their own source
- 11
- Carrying a caveat
- 3
- Verified
- 2026-09-05
measured in export credit as a share of the retail rate
the other 2 inherit the file source or record an absence
marked in the table below
all on one date
What this decides
The bill with solar, in every scenario, and the whole battery case.
Each record was read on 2026-09-05 from the rule that governs it: a state commission regulation, a statute, a utility tariff sheet, or a state agency's own publication. DSIRE and installer pages were not used as authority. Where a state has several large utilities with materially different rules, the record names the one it follows rather than averaging them. ratio_basis says how the number itself was obtained: `source` when the cited document states it, `derived` when it is computed from two cited figures, `modelling_choice` when no source states a single number - those keep needs_verification true.
limitThe engine credits every exported kilowatt-hour at
export_ratio with NO annual ceiling. That is correct for a system sized to the household's own use, where annual production is about equal to annual consumption and the year-end surplus is near zero - which is how the engine sizes by default. It is NOT correct for a system that generates materially more than the home uses: several states settle the year-end surplus at a lower rate than the in-year export credit (see annual_surplus), and some utilities will not approve a system larger than the customer's recent usage at all (see sizing_cap). Do not use these figures for a deliberately oversized system.Every record
| Record | Rule | Export credit | Verified | Source |
|---|---|---|---|---|
| Any state with no rule on file fallbacknot published | no rule on file | 30% | — | — |
| Conservative fallback for a state with no record. A missing value must never produce a more optimistic result than a known one: 0.30 sits near the low end of real export rates (California's net billing tariff works out near 0.20). Falling through here is an error flag and disqualifies the state from being served; tests assert this default stays at or below 0.5. | ||||
| Arizona | net billing, export credited below retail | 37% | 2026-09-05 | aps.com |
| Utility read: Arizona Public Service (the state's largest electric utility). Tucson Electric Power and UNS Electric set their own Resource Comparison Proxy rates.. Rate Rider RCP, A.C.C. No. 6248, effective 1 September 2026 under Arizona Corporation Commission Decision No. 82122. Exports are metered instantaneously and credited at the Resource Comparison Proxy export price: $0.05554/kWh for the 2026 tranche (1 September 2026 to 31 August 2027). A customer's rate is fixed for 10 years from interconnection, and the RCP may not fall by more than 10% a year. Export credits above the monthly bill carry forward; a balance over $25 after the December bill is paid out by cheque. $0.05554/kWh from the tariff sheet against an Arizona residential retail rate of 15.18 c/kWh (EIA 2026-06) gives 0.366, recorded as 0.37. | ||||
| California | net billing, export credited below retail | 20% | 2026-09-05 | cpuc.ca.gov |
| Utility read: PG&E, SCE and SDG&E (the three investor-owned utilities the tariff covers). Net Billing Tariff, adopted in CPUC Decision D.22-12-056 and applied to new customers from 15 April 2023. Exports are compensated at Avoided Cost Calculator values, which the CPUC describes as usually lower than retail rates but able to rise above them on late summer evenings; the rate differs every hour. NEM 2.0 customers keep their tariff for 20 years from interconnection. The CPUC states the mechanism but publishes no single average export price. Independent 2026 summaries put the average export credit at roughly $0.05-$0.08/kWh against a California residential retail rate of 34.74 c/kWh (EIA 2026-06), i.e. 0.14-0.23. The record uses 0.20. Replace it with a utility-published average when one is available. | ||||
| Connecticut | full retail net metering | 100% | 2026-09-05 | portal.ct.gov |
| Utility read: Eversource and United Illuminating, under one PURA programme.. Net metering was replaced by the Residential Renewable Energy Solutions programme. Its Netting tariff compensates net excess generation at the prevailing retail rate, inclusive of both supply and delivery charges, on a 20-year term. Projects enrolling in 2026 pay a solar energy adjustment of $0.0402/kWh on total solar production, not only on exports, and the 2026 REC payment rate is $0. The alternative Buy-All tariff sells all production to the utility at a fixed rate and is not modelled here. Retail-rate netting, with the 2026 production charge modelled separately: it applies to everything the array generates, so it cannot be folded into an export ratio. | ||||
| Florida | full retail net metering | 100% | 2026-09-05 | floridapsc.com |
| Utility read: All investor-owned utilities, under Rule 25-6.065 F.A.C.. Rule 25-6.065, Florida Administrative Code, provides that during any billing cycle excess customer-owned renewable generation delivered to the utility's grid shall be credited to the customer's energy consumption for the next month's billing cycle: a kilowatt-hour credit at the retail rate. The rule covers systems up to 2 MW. | ||||
| Illinois | net billing, export credited below retail | 49% | 2026-09-05 | ipa.illinois.gov |
| Utility read: Commonwealth Edison (the state's largest electric utility). Ameren Illinois changed on the same date; MidAmerican from 1 January 2025.. Retail-rate net metering closed to new customers after 31 December 2024 under Public Act 102-0662. The Illinois Power Agency states that full retail rate net metering is no longer available and that new customers receive only energy supply credits for the excess energy they send back to the grid. Energy generated and used on site is still worth the full retail rate; only exports are credited at the supply rate. Customers interconnected before the cut-off keep retail-rate netting. ComEd's published supply price to compare was about 9.66 c/kWh through May 2026, rising to about 10.399 c/kWh for summer 2026, against an Illinois residential retail rate of 19.89 c/kWh (EIA 2026-06): 0.49 to 0.52. The record uses the lower figure, 0.49. The supply price is set each June and this ratio moves with it. | ||||
| Maryland | full retail net metering | 100% | 2026-09-05 | law.justia.com |
| Utility read: All electric companies, under Maryland Public Utilities Article 7-306.. Monthly kilowatt-hour credits offset consumption at the retail rate. By default any balance still unused is settled each April at the generation or commodity portion of the rate, averaged over the previous 12 months; a 2023 law lets a customer instead roll credits forward indefinitely at full retail value. Systems may not exceed 2 MW. Full retail within the year. The April settlement rate applies only to a balance the customer never used, which a system sized to annual load largely avoids. | ||||
| Massachusetts | full retail net metering | 100% | 2026-09-05 | mass.gov |
| Utility read: All distribution companies (Eversource, National Grid, Unitil) under one regulation.. 220 CMR 18.04 requires each distribution company to calculate, for a Class I solar net metering facility, a net metering credit equal to 100% of the net excess kilowatt-hours multiplied by the sum of the distribution company charges applicable to the rate class. The Department of Public Utilities raised the threshold for netting without a cap allocation from 10 kW to 25 kW. | ||||
| New Jersey | full retail net metering | 100% | 2026-09-05 | cleanenergy.nj.gov |
| Utility read: All electric distribution companies, under N.J.A.C. 14:8-4.. New Jersey's Clean Energy Program states that customers receive full retail credit on their utility bill for each kilowatt-hour their system produces over the course of a year. At the end of the annualised period any remaining excess is credited at the wholesale value of electricity. A system may not be sized above the customer's annual electricity needs, which is how the engine sizes it, so annual excess is small. | ||||
| New York | full retail net metering | 100% | 2026-09-05 | nyserda.ny.gov |
| Utility read: Con Edison (the state's largest electric utility). Every utility publishes its own Customer Benefit Contribution rate; the 2026 residential rates range from $0.97 to $1.67 per kW per month.. A residential system under 25 kW may still take Phase One net metering, which credits exported kilowatt-hours at the full retail rate; the Value of Distributed Energy Resources value stack is the alternative. Systems interconnected from 1 January 2022 also pay a Customer Benefit Contribution, a monthly charge on the project's DC system size that funds public benefit programmes and is set so that a customer's annual contribution to those programmes is the same with or without solar. CBC rates are published annually by each utility and are not locked in at interconnection. Full retail credit for exports; the CBC is a separate charge on system size, modelled here at Con Edison's 2026 residential rate of $1.13 per kW per month. | ||||
| Pennsylvania | full retail net metering | 100% | 2026-09-05 | pacodeandbulletin.gov |
| Utility read: All electric distribution companies, under 52 Pa. Code Chapter 75.. 52 Pa. Code 75.13 requires an electric distribution company to credit a customer-generator at the full retail kilowatt-hour rate, which shall include generation, transmission and distribution charges. Excess kilowatt-hours are carried forward and credited against later billing periods at the full retail rate. A residential system may not exceed 50 kW. | ||||
| Texas modelling choice | varies by utility or retail provider | 70% | 2026-09-05 | puc.texas.gov |
| Utility read: None. In the competitive market each retail electric provider sets its own buyback plan; outside it, the utility must buy at avoided cost.. Texas has no statewide net metering mandate. The Public Utility Commission requires utilities outside the competitive market to purchase distributed renewable generation at avoided cost; inside it, whether exports are bought at all, and at what price, is a term of the retail provider's plan. Buyback plans range from one-for-one credit on the energy charge to no export credit at all, and the plans with the best buyback often carry a higher energy rate. No source states a single Texas number, because there is not one. 0.70 stands in for a typical energy-only buyback - a credit on the energy charge but not on delivery - and is a modelling choice, not a measured value. The record stays flagged as unverified, so every Texas figure on the site carries a warning. A reader should put their own provider's buyback rate into the calculator. | ||||
| Washington modelling choicenot published | full retail net metering | 100% | — | — |
| Not served: Washington has no installed-cost record, so no page is published and this value is not used. Verify against RCW 80.60 and the serving utility's tariff before it is. | ||||
Source column links the page or endpoint the value was read from. Where a row has no link of its own, it inherits the file-level source.
One primary source per state: a commission order, a tariff sheet or a statute. Never an aggregator.
Take it
- export-rules.json
The file the engine actually reads, unaltered, with the documentation blocks it carries.
- export-rules.csv
The 13 records flattened for a spreadsheet: value, verified date, source, caveats, note.
Our compilation is free to reuse with a link back. The underlying data is not ours to license — follow the source on any row for the authoritative version and its own terms. The full position.
The rest of the data
- Electricity prices
What a residential kilowatt-hour costs, by state. The single biggest driver of whether solar pays.
- Solar yield
How much electricity a kilowatt of panels makes in a year, by place. The only pure physics on the site.
- Installed cost
What a system costs installed, on both published bases: competitive quotes, and what buyers actually paid.
- State incentives
What a buyer can actually claim from a state, read from the statute or programme that grants it.
- Federal policy
The federal credit as data, versioned by year, with the dated events that changed it.
- Modelling assumptions
Everything the model assumes rather than sources: panel wattage, degradation, loan terms, escalation.
Published 6 September 2026. Last verified 5 September 2026. A figure here that looks wrong is the mail we most want: tell us, and we publish corrections. The formulas that consume these records are on the methodology page.