Estimate annual net-metering credit value from solar output, usage and export rates. Understand how annual netting differs from hourly net billing and TOU.
Quick answer
Annual netting offsets production up to consumption at retail. Net billing offsets only assumed on-site self-use at retail; remaining generation earns the export rate.
Notes updated 2026-10-07
Best for
Homeowners pressure-testing solar proposals before signing.
Inputs needed
electric usage, local rate, system size or quote assumptions
Formula used
Annual netting offsets production up to consumption at retail. Net billing offsets only assumed on-site self-use at retail; remaining generation earns the export rate.
Method references
System Advisor Model
Author profile: Marcus Vance . Read the methodology and recheck local tariff, quote, and incentive details before deciding. Attribution is not a record of independent technical review.
kWh
kW
hrs
$/kWh
1 = retail value, 0.25 = one quarter of retail. This is not an imported tariff.
Wattcrunch Solar Planning Report
Generated 10/25/2026 · Verify assumptions with your utility and installer.
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What is the difference between net metering and net billing?
Annual retail netting balances generation and consumption over a year. Net billing can settle imports and exports separately at different rates during each interval. A low annual surplus rate alone cannot model hourly net billing.
Where should I verify export credit rules?
Use the current account tariff and interconnection agreement. Settlement periods, credit expiration, fixed charges and grandfathering dates can matter more than the advertised export price.
Why does net billing save less than full retail net metering?
Under annual retail netting, eligible exports can offset later imports. Under net billing, unused production is sold at a separate export price. Even if annual usage exceeds generation, midday exports can earn less than the evening electricity you purchase.
Same 10,000 kWh production and 12,000 kWh household use
Settlement assumption
Retail-valued energy
Annual energy value
Annual retail netting
10,000 kWh
$2,500.00
Net billing, 40% self-use
4,000 kWh
$1,360.00
Illustrative assumptions: $0.25/kWh avoided import, $0.06/kWh export, 40% self-use for net billing. Annual netting assumes eligible retail banking. Fixed charges remain; monthly caps, TOU, credit expiry and demand charges are not simulated here.
What to check on your bill or installer proposal
Find the exact tariff on your bill and your permission-to-operate date.
Check how unused credits settle at month-end and year-end.
Use interval readings for time-varying export credits, not an annual average presented as an exact bill.
Example and calculation notes updated . Method references are listed below; example rates are not verified utility tariffs.
How does this net metering estimate work?
Annual netting offsets production up to consumption at retail. Net billing offsets only assumed on-site self-use at retail; remaining generation earns the export rate.
A worked example with explicit assumptions
With 10,000 kWh produced and 8,000 consumed, annual retail netting at $0.20 values 8,000 kWh at $1600.00. At $0.05/kWh, 2,000 surplus kWh add $100.00, totaling $1700.00. This is not hourly net billing.
Reproducible example generated from the same calculator functions used by the tool. Inputs are illustrative, not measured customer results.
What should I verify before using the result?
Select the settlement model explicitly. The net-billing option uses an assumed annual self-use share, not actual hourly settlement. Hourly exports can occur even when annual usage exceeds generation.
Use your bill or written equipment quote, run a conservative scenario, and compare the result with the same inputs in another model.
Planning notes updated October 12, 2026. Example assumptions are not a local tariff.
Why do inverter generation and meter exports disagree?
The inverter measures generation; a bidirectional utility meter measures flows across the grid connection. Direct self-use does not appear as exported energy.
Worked example: If solar generates 20 kWh and exports 12 kWh over matching intervals, direct use is 8 kWh in a simple solar-only system.
What to verify: With storage, other meters and conversion losses, a full energy-flow reconciliation is required. Match timestamps and billing periods.
Planning notes updated October 12, 2026. Example assumptions are not a local tariff.
Pressure-test the estimate
Treat the result as a planning range, not a promise. Re-run it with a lower and higher production estimate, your actual utility tariff, and the written installer quote.
Check roof shade, orientation, tilt, and equipment losses.
Separate cash price, financing fees, battery cost, and roof work.
Verify export credits, fixed charges, and interconnection rules.
Confirm incentive eligibility, deadlines, and tax treatment.
Sources behind this estimate
Use the method references below to check the formula and its limitations. Input defaults and illustrative scenarios are not current tariffs, guaranteed output or live installer quotes.
Utility export rates, eligibility rules, and installer pricing can change. Confirm the applicable tariff, interconnection requirements, and tax treatment before making a purchase decision.
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Frequently asked questions
Is annual net metering the same as net billing?+
No. Annual netting can offset exported kWh against later imports at retail, subject to the account rules. Net billing values exports separately, often by time. The annual self-consumption approximation is not an interval settlement calculation.
How do I use the net metering calculator?+
Start with your actual usage, equipment or quote inputs, keep the displayed units, and change one assumption at a time. Select the settlement model explicitly. The net-billing option uses an assumed annual self-use share, not actual hourly settlement. Hourly exports can occur even when annual usage exceeds generation.
What calculation does this tool use?+
Annual netting offsets production up to consumption at retail. Net billing offsets only assumed on-site self-use at retail; remaining generation earns the export rate.
Can I check the arithmetic with an example?+
With 10,000 kWh produced and 8,000 consumed, annual retail netting at $0.20 values 8,000 kWh at $1600.00. At $0.05/kWh, 2,000 surplus kWh add $100.00, totaling $1700.00. This is not hourly net billing.
What could change the accuracy of my result?+
Select the settlement model explicitly. The net-billing option uses an assumed annual self-use share, not actual hourly settlement. Hourly exports can occur even when annual usage exceeds generation.
Can I use the estimate outside the United States?+
Physical kW and kWh calculations use the same units internationally. Dollar results, regional defaults, emissions factors, incentives and utility guidance are US-oriented. Replace rate and production assumptions with local values; do not apply US tax or export rules abroad.
Can I print or save results without registering?+
Use Print / PDF to save this page from your browser without an email address. The solar plan stores supported scenario inputs in your browser; private files should be checked and redacted before uploading for extraction.
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