How do you apply for a G99 connection for your business?

Apply to your distribution network operator with the proposed generation design, equipment evidence and requested export capacity before installing. G99 generally covers generation above 16 amps per phase, or equipment outside G98 conditions [S1]. Confirm the correct application route, accept the connection offer and complete the required commissioning paperwork before treating the process as finished. Checked October 2026.

Last checked 17 October 2026

How complicated is a business G99 application?

G99 is the Energy Networks Association (ENA) engineering recommendation for connecting generation in parallel with the public electricity network. Your distribution network operator (DNO) assesses your design [S1]. Start with who your DNO is, rather than sending the form to the company that sells you electricity.

Make this a managed design task. Agree who prepares the drawings, answers technical queries and submits completion documents. Keep the same application reference throughout. This guide covers Great Britain; the ENA guide says Northern Ireland has a separate process [S2].

Which form should you use for G99 or G98?

Step one: establish the complete electrical arrangement

G98 generally covers fully type-tested generation up to 16 amps per phase, equivalent to 3.68 kilowatts (kW) per phase. G99 applies above that or where G98 conditions are not met [S1]. Read G98 versus G99.

Ask your designer to record existing and proposed inverters, batteries and export controls. kW measures power; kilowatt-hours (kWh) measure energy. A battery’s kWh capacity does not describe its maximum power. Do not select the route from the panel capacity alone: for inverter-connected generation, NGED uses the inverter’s continuous steady-state rating [S1].

Step two: select equipment evidence and the form

Look up the exact device in the ENA type-test register’s successor, Connect Direct. The old register closed in April 2024 and directs users there for current compliance status [S3]. Ask for the register reference, model, applicable standard and supporting report to be saved with your design.

For smaller qualifying projects, Form A1-1 is the simplified application. Larger schemes use the standard G99 application [S1]. Have the DNO confirm the route at a size boundary or where equipment is not fully type tested. SP Energy Networks publishes the G98 and G99 forms together, including generating-unit data sheets [S8].

What information does your G99 application need?

Step three: prepare one consistent submission pack

NGED’s application page asks for location plans, site layout plans and manufacturers’ specifications. It also provides separate generating-unit, transformer and storage data forms [S4]. Use this submission checklist:

• Site address, applicant, owner contact and authority for the designer to act.
• Existing connection details and the supply’s Meter Point Administration Number (MPAN).
• Existing generation and the complete proposed solar and storage arrangement.
• Site and location plans, plus a single-line electrical diagram.
• Equipment ratings, type-test references and protection information.
• Requested maximum import, export and any export-limitation design.
• Proposed commissioning date and the person responsible for responding to queries.

Ask the designer to reconcile every rating across the drawings and forms. SSEN explicitly requires authority where the applicant is not the landowner or occupier, subject to its stated exceptions [S6]. Get that signature before submitting, rather than letting it become a later query.

Where should you send your G99 application?

Step four: use your network’s generation route

These are entry points, not interchangeable application portals. Open the relevant source link below and choose the generation route for your project.

UK Power Networks also supports small generation applications through its installer portal, Smart Connect [S11]. For Northern Powergrid, ask its connections team for the current commercial generation route. Its website could not be verified during this check, so no specific portal address is asserted here.

Save the submitted pack and acknowledgement. Ask when the DNO regards the application as complete and what work, if any, you may proceed with while it is being assessed.

How much does a G99 application cost, and how long does it take?

Step five: separate assessment, construction and commissioning costs

Do not assume a nationwide flat application fee. NGED publishes assessment and design charging guidance [S9]. Ask for an itemised written response covering:

NGED says witness testing can incur a fee [S1]. Compare the written scope with your grid connection cost assessment.

The ENA guide distinguishes quotation targets by scope. For work including both contestable and non-contestable elements, it lists 45 working days at low voltage and 65 at high or extra-high voltage. These are quotation timescales, not dates for electricity generation to start [S2]. Ask which standard applies to your application.

Incomplete technical details, changed equipment, reinforcement and land permissions can add steps. Keep a query log with an owner and response date. Budget separately for the physical works and consents before promising an opening date; see connection timescales.

What if the DNO limits your solar or battery export?

Step six: review the offer before accepting

An export-limitation scheme restricts net power passing through the connection. NGED describes it as a possible alternative to waiting for, or contributing towards, reinforcement [S10]. G100 is the engineering recommendation for customer export and import limitation schemes [S3]. Read G100 export limitation.

Ask your designer to rerun generation and financial estimates using the offered export limit. Compare a smaller system, controlled export and reinforcement. Check equipment settings, failure behaviour and testing with the DNO. A zero-export proposal still needs the applicable connection assessment: parallel generation is the relevant issue, not just whether you intend to sell electricity [S1] [S10].

What paperwork completes the G99 connection?

Step seven: commission and submit the completion notice

Arrange testing and any DNO witness visit before the planned connection date. For Type A projects, the ENA guide requires the Installation Document within 28 days of commissioning, including the commissioning day. Witnessed tests can be documented on the day [S2].

Ask for the applicable G99 completion notice, signed declarations, test results and final drawings. Confirm the DNO received them. Keep application approval and commissioning evidence together; they serve different purposes.

What should you do next?

Prepare your postcode, existing supply details, proposed solar capacity and battery power, then get matched with an installer that covers your area. Use the commercial solar guide to connect the network offer to your business case.

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