How does G100 export limitation work for your business?

G100 sets requirements for schemes that control electricity flowing across your site's grid connection. It can cover export, import or both. The Energy Networks Association describes Issue 2 as supporting customer limitation schemes on constrained networks [S1]. Your network operator must accept the proposed arrangement; export limitation alone is not generation connection permission. Checked October 2026.

Last checked 16 October 2026

What is a G100 export limiting scheme?

An export limiting scheme controls the electricity your site sends into the local network. G100 is the Energy Networks Association engineering recommendation for customer export and import limitation schemes. Its overview describes monitoring at the connection point and controlling relevant equipment [S1].

Your distribution network operator, or DNO, manages the local network. It needs to assess the proposed generation, storage and load arrangement. Ask your designer to show the agreed boundary on a single-line diagram: a simplified drawing of the electrical connections. That diagram should help everyone discuss the same site limit.

Use the generation connection guide for the approval route. G99 is the engineering recommendation covering relevant generation connected in parallel with the network. Keep the generation approval and the limitation scheme as separate entries in your project checklist [S3].

Can your business have more generation than its export limit?

Ask the DNO to assess that design rather than assuming the answer from the size of the roof. A limitation scheme can provide an option on a constrained network, but the G100 scope retains other network restrictions [S2]. The permitted generation rating and the agreed export ceiling are separate questions for the application.

For an illustration, assume solar produces 60 kW, the building uses 35 kW and the accepted export cap is 20 kW. Here kW means kilowatts, a measure of power. Before control action, the surplus would be 60 minus 35 = 25 kW. The illustrative surplus above the cap is 25 minus 20 = 5 kW. These are assumed inputs explaining the arithmetic, not a proposed design or a permitted operating tolerance.

Ask your designer to repeat that exercise for quiet trading days and a full battery. A proposal that depends on every charger being occupied should be challenged with an empty-car-park scenario. Request a model that shows where surplus energy goes when your normal demand disappears.

How does G100 work with batteries and EV chargers?

The important boundary is the whole connection point, not just a solar inverter. Ask for a schedule covering existing generation, new solar, batteries and charging equipment. Have the designer mark which devices the scheme measures and controls. The ENA’s scheme description concerns relevant devices and the direction of flow across that boundary [S1].

Use solar, batteries and charging together to prepare your brief. Request a coordinated design even where different contractors supply the equipment. Name someone to own the interface questions and the complete commissioning demonstration.

Does G100 remove the need for G99 approval?

No. The ENA register distinguishes generation connection standards from the limitation requirements [S3]. A setting labelled “zero export” does not itself demonstrate that the proposed installation has an accepted connection arrangement. Ask for the application reference and written response applicable to your equipment.

Do not authorise procurement on the basis of a verbal statement that approval will follow. Request a schedule showing which equipment is conditional on the DNO response. If a substitution is proposed, have the designer confirm whether the application and compliance evidence need revisiting before accepting the change.

For sites with flexible network access, request a specific compatibility check. G100’s scope warns that a customer limitation scheme may interact with active network management instructions [S2]. See the flexible connection guide before combining those controls.

What G100 forms and test evidence should you request?

Use the ENA Type Test Register to locate documentation for the exact proposed equipment. The ENA explains that manufacturers upload and maintain their own records [S3]. Ask your designer to identify the entry and explain how it relates to the full system being installed, rather than accepting a generic product-family statement.

Request a handover pack containing the accepted connection terms, final diagram, equipment schedule, agreed settings and commissioning results. Ask who may change settings and how later changes will be recorded. These are procurement requests to make before contract award, so the contractor can include the work in its scope.

Arrange a handover discussion with the person responsible for your site’s energy systems. Ask them to explain how a control fault is reported and what action the site team should take. Keep operational instructions with the records, rather than relying on access to an installer’s personal account.

How much does G100 export limitation cost?

There is no project price in the ENA scope documents used here. Obtain an itemised quotation for your actual design. Compare the following scope rather than assuming that a limiter is always a separate box:

• Design and application support, including revisions after the network response.
• Measurement equipment, control equipment and communications needed for the proposed layout.
• Installation, commissioning, demonstration and final documentation.
• Monitoring, fault response and any recurring service charges you agree to buy.

Ask for the alternative proposal as well: a smaller system, a different connection arrangement or a staged installation. Compare the effect on useful energy and curtailed output using stated assumptions. Do not count unapproved export income in the business case. The solar self-consumption guide helps frame that comparison.

What should you do next?

Gather your existing generation records, electricity data and proposed equipment schedule, then get matched with an installer that covers your area. Ask for the connection and control design to be assessed together.

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