Net metering can reduce a solar electric bill, but the value of exported energy depends on the utility’s tariff, billing cycle, and compensation rules. This guide explains how solar credits work, compares net metering with net billing and buy-all-sell-all programs, and provides a reusable worksheet for checking your monthly results.
Overview
Solar panels produce electricity when sunlight is available. Your home uses that electricity first. If the system produces more than the home is using at that moment, the excess may flow through the utility meter to the grid. When the panels are not producing enough, the home draws electricity from the grid.
Under traditional net metering, the utility tracks electricity imported from the grid and electricity exported to it. The bill is based on the net difference over a defined billing period, subject to the utility’s rules. In a simplified example, a home might import 800 kilowatt-hours (kWh) during a month and export 500 kWh. If the tariff allows those quantities to offset one another on the same billing basis, the energy portion of the bill may reflect 300 kWh of net consumption. Fixed charges, taxes, delivery charges, and other line items may still apply.
The important point is that one exported kWh does not always have the same value as one imported kWh. Some utilities credit exports at the applicable retail energy rate, while others use a separate avoided-cost, wholesale, or tariff-defined rate. Some programs apply credits monthly, while others carry them forward to a later true-up or settlement date. Rules can also differ by utility territory, system size, interconnection agreement, and customer type.
Before estimating savings, locate the utility’s current distributed-generation tariff or customer agreement. Confirm the export rate, credit expiration rules, fixed charges, time-of-use periods, monthly limits, and any annual settlement provisions. Policies can change, so a general explanation is a starting point rather than a substitute for the tariff that applies to your address.
Net metering, net billing, and buy-all-sell-all compared
| Program | How energy is valued | What to check |
|---|---|---|
| Net metering | Imported and exported energy may be offset under the program’s billing rules. | Credit carryover, true-up timing, fixed charges, and whether export credits match retail energy charges. |
| Net billing | Energy used from the grid and energy sent to the grid are often priced separately. | The import rate, export rate, time-of-use schedule, and how credits appear on the bill. |
| Buy-all-sell-all | The solar system’s production is sold to the utility, while the property buys its electricity under the normal retail tariff. | Contract terms, production meter requirements, payment or credit timing, and whether on-site use is treated differently. |
A solar battery can change the amount of energy exported. Instead of sending all midday surplus to the grid, a battery may store some of it for evening use or backup power. That can improve self-consumption, but the financial result depends on battery cost, efficiency, operating settings, outage goals, and the utility’s export compensation. For related sizing considerations, see the Solar Battery Backup Guide.
Checklist by scenario
If you are considering home solar
- Identify the electric utility serving the property and download its current solar or distributed-energy tariff.
- Ask whether the program is net metering, net billing, buy-all-sell-all, or another structure.
- Find the approved export-credit rate and determine whether it varies by time of day.
- Check whether credits roll forward, expire, or are settled at a designated annual or contractual date.
- Record fixed monthly charges and charges that are not offset by solar credits.
- Compare proposed system production with your hourly or monthly electricity use rather than sizing only for annual consumption.
- Request a written explanation of the expected bill under the applicable tariff before signing an installation agreement.
A production estimate is more useful when paired with your actual bills. The Solar Panel Cost Calculator and home solar sizing guide can help organize system assumptions, but the utility’s compensation rules still determine how exported energy is valued.
If you already have solar
- Save the first bill after interconnection and compare it with a pre-solar bill from a similar season.
- Record imported kWh, exported kWh, opening credits, new credits, used credits, and the closing balance.
- Check whether the meter was changed or reconfigured and whether the bill identifies solar production correctly.
- Review the bill for demand charges, minimum charges, taxes, and delivery fees that may remain after energy credits are applied.
- Compare the bill’s production and export data with your inverter or monitoring app.
- Note unusual weather, shading, equipment downtime, or changes in household electricity use.
If you are comparing a battery
- Determine how much daytime solar is currently exported and how much evening electricity is imported.
- Ask how the battery will be dispatched: for self-consumption, time-of-use savings, backup, or a combination.
- Compare the value of using stored energy at home with the credit available for exporting it.
- Check whether the battery can charge from solar during an outage and which circuits it can support.
- Include installation, controls, warranty terms, efficiency losses, and replacement assumptions in the comparison.
For component tradeoffs, the best solar battery comparison guide covers capacity, power, and total-cost questions. A battery is not automatically the best financial choice simply because export credits are limited.
Monthly solar-credit worksheet
Use the following fields in a spreadsheet or on a printed bill log:
- Billing period and number of days
- Electricity imported from the grid: ___ kWh
- Electricity exported to the grid: ___ kWh
- Opening credit balance: ___ kWh or $___
- New export credits: ___ kWh or $___
- Credits applied this period: ___ kWh or $___
- Closing credit balance: ___ kWh or $___
- Energy charges: $___
- Fixed, delivery, demand, tax, and other charges: $___
- Total bill: $___
- Notes about weather, usage, outages, or equipment: ___
If the utility uses separate prices for imports and exports, record the rates beside each quantity. This makes it easier to distinguish a reduction in electricity use from a credit earned for exported solar.
What to double-check
Credit units: A bill may display credits in kWh, dollars, or both. Do not assume that a kWh credit has the same value as a retail kWh charge.
Time-of-use pricing: Under time-varying rates, electricity imported during an expensive period may not be offset by electricity exported during a less valuable period. Review the rate schedule and the meter’s intervals.
True-up language: A true-up may reset a credit balance, convert credits to a different value, or settle the account under a specific rule. Read the agreement instead of assuming credits continue indefinitely.
System size and interconnection limits: The utility may impose conditions on system capacity, export capability, or equipment. A larger solar array is not necessarily more valuable if surplus production receives a lower credit or cannot be exported as expected.
Changes in usage: Electric vehicles, heat pumps, electric water heating, occupancy changes, and efficiency upgrades can alter when and how much electricity the home uses. Reassess the comparison after a major change.
Monitoring accuracy: Inverter monitoring estimates and utility meter data may measure different points in the system. Small differences can occur, but persistent or large discrepancies deserve investigation. The solar panel maintenance checklist can help with basic inspection and troubleshooting.
Common mistakes
- Using a national estimate: Solar buyback rates and billing practices are local. Use the tariff for the property’s utility and service class.
- Counting production as savings: The value of solar depends on when electricity is produced, when it is used, and how exports are credited.
- Ignoring non-energy charges: Solar credits may reduce energy charges without eliminating fixed or delivery-related charges.
- Overlooking seasonal patterns: A credit balance built during sunny months may be consumed during winter, while a system may produce less than expected during extended cloudy periods.
- Assuming a battery guarantees savings: Storage has a cost and loses some energy during charging and discharging. Compare its purpose and expected value with the actual tariff.
- Failing to keep records: Without copies of bills, agreements, and meter readings, it is difficult to identify a billing error or explain a change in savings.
When to revisit
Review your net-metering position when you receive a tariff notice, change electricity plans, add a battery, replace an inverter, or make a major home-electrification upgrade. It is also useful to reconcile the account monthly and perform a deeper review before the utility’s annual true-up or settlement period.
At each review, repeat three steps: verify the current export rules, compare utility data with system monitoring, and update the value of imported and exported electricity in your savings estimate. If the utility changes rates or billing software, save the prior bill and the new tariff so you can identify what changed.
Before committing to solar or storage, ask the installer and utility for written answers to these questions: What program applies? What is the export-credit formula? When do credits expire or settle? Which charges remain? How will a battery affect exports? Keep those answers with your interconnection documents. Policies and rate structures can change, but a clear monthly record gives you a reliable basis for evaluating your solar electric bill over time.
