Solar meters — production vs net (bidirectional)

Solar interconnections involve metering, but not every meter measures the same thing. A production meter counts what the array makes; a net (bidirectional) meter tracks the flow between the home and the grid. Understanding the difference clears up billing and program questions. Here is what each one does.

Production meter

A production meter measures the total energy the PV system generates — every kilowatt-hour the array produces, whether it is consumed in the house or sent to the grid.

• It sits on the solar output circuit, before energy mixes with household loads.
• It answers the question "how much did the system make?"
• Utilities and incentive programs use it to pay production-based incentives (for example, per-kWh generation credits or SREC tracking).

A production meter is unidirectional in purpose — it only cares about generation.

Net (bidirectional) meter

A net meter, or bidirectional meter, measures energy crossing the point of common coupling in both directions:

• Import — energy the home draws from the grid when loads exceed solar.
• Export — energy pushed to the grid when solar exceeds loads.

Under net metering, the utility nets exports against imports over the billing period. A modern bidirectional meter records both channels separately so the utility can apply the correct rate to each.

Why the distinction matters

The two meters answer different questions:

• Production tells you and the program how much the system made.
• Net metering tells the utility how much to bill or credit based on the balance of import and export.

A home can self-consume most of its solar and export little; in that case the production meter shows high generation while the net meter shows small export. Both readings are correct — they measure different things.

How they appear on the interconnection

On the one-line diagram and site plan, the utility typically defines where its revenue (net) meter goes and whether a separate production meter is required. Common arrangements:

• Utility bidirectional meter at the existing service position.
• Optional production meter (or inverter-reported production) on the PV output.

Some utilities accept inverter-measured production instead of a dedicated meter, since inverters log generation internally. Always confirm the utility's metering requirement early — it affects the equipment list and the interconnection application. Consumption-side data from CTs is a separate topic covered in solar consumption monitoring and CTs.

Getting it on the plans

Metering details, the point of interconnection, and disconnect locations all belong on the permit drawings a reviewer checks — see what is in a solar permit set for the full list.

Production meters count generation; net meters count the give-and-take with the grid. Confirm which the utility requires before finalizing the design, and have a licensed electrician or PE review the interconnection. New to the workflow? Try the DIY workflow or start at the home page.

Educational reference, reviewed 2026-07. A design aid, not a substitute for a licensed electrician or PE. Confirm the enforced NEC edition and local amendments with your AHJ.