- G98 limit, single phase
- 3.68 kW
- G98 limit, three phase
- 11.04 kW
- Fast Track connection fee, ex VAT
- £311
The short answer
G98 vs G99 — NIE Networks grid rules in plain English
Before solar or a battery connects to the Northern Ireland grid, NIE Networks needs the right notification or approval. G98/NI covers most small domestic micro-generation under a fit-and-inform process (typically up to 16 A per phase ≈ 3.68 kW on single-phase). G99/NI — including Fast Track — covers larger or more complex systems and requires approval before installation. Fee figures follow NIE Networks Statement of Connection Charges V1.16 (effective 1 July 2026). The Smart Export Guarantee does not apply in Northern Ireland.
Why NI grid rules matter
If you install solar — with or without a battery — that can export to the public network, you are connecting generation to NIE Networks. The route depends mainly on capacity installed and how much you may export.
Northern Ireland uses G98/NI and G99/NI. These are not identical to every GB blog post, and the Smart Export Guarantee (SEG) does not apply here. Grid connection and export payments are related but separate — see solar export payments in Northern Ireland.
Fee figures below follow NIE Networks Statement of Connection Charges V1.16 (effective 1 July 2026). Charges change — confirm on your quote.
What G98/NI is
G98/NI covers micro-generation: small, type-tested equipment under a "fit and inform" process.
For many homes that means the installer fits and commissions an approved micro-generator, notifies NIE Networks (Stage 1) — typically within 30 days of commissioning — NIE Networks may arrange an import/export-capable meter if needed, and you arrange an export tariff with your electricity supplier (NIE does not buy your power).
| Supply type | Typical G98/NI limit |
|---|---|
| Single-phase (most houses) | Up to 16 A per phase ≈ 3.68 kW |
| Three-phase | Up to 16 A per phase ≈ 11.04 kW total |
G98 fees and Stage 2
Within these limits with type-tested kit, G98/NI is usually the path. Above them → G99/NI.
Application fee: £0 to submit G98/NI Stage 1 or Stage 2. Stage 2 may still trigger network reinforcement costs if NIE's study finds them.
G98/NI Stage 2 applies when NIE must assess the local network first (e.g. certain multiple installations nearby). Capacity is still G98-scale; Stage 2 timescale depends on job size and volume. Your installer should flag Stage 2 if it applies.
What G99/NI is
G99/NI covers generation that does not qualify for G98 fit-and-inform. Critically: approval before installation — not install-then-notify.
Since 1 May 2026, NIE Networks splits G99 more clearly into Fast Track and full G99.
G99/NI Fast Track
Streamlined G99 when published criteria are met (re-check live NIE pages): Total Installation Capacity (TIC) up to 60 A per phase ≈ 13.8 kW; individual inverter limited to 32 A ≈ 7.36 kW; export limited to 16 A per phase ≈ 3.68 kW (often via G100 export limitation) — larger arrays for self-use are common.
Still application-and-approval. Incomplete packs stay outside the queue until valid.
Connection Application Fee (CAF), Schedule 2: £311 ex VAT (£373.20 at 20% VAT) for Fast Track, per Statement V1.16.
Timescales: NIE's licence standard is to issue an offer within 3 months of a valid application and fee. Installers often report roughly ~20 working days once the pack is valid — that shorter figure is installer experience, not a published NIE FAQ SLA, so treat it as typical practice rather than a guarantee. Once you have an offer, acceptance is usually within 90 days.
Full G99/NI (above Fast Track)
Exceeds Fast Track limits or fails Fast Track criteria → fuller design, quotation and connection agreement. Common for larger commercial arrays and sites needing network studies or reinforcement.
Larger schemes (≥ 5 MW) may attract additional SONI charges. Offer within 3 months of a valid application (the Utility Regulator can extend that licence period). Accept within 90 days.
| Total capacity | CAF (ex VAT) |
|---|---|
| ≤ 20 kW | £702 |
| > 20 – 150 kW | £2,106 |
| > 150 kW – 2 MW | £7,019 |
| > 2 MW | £10,527 |
Domestic vs larger / three-phase
- ~3–3.68 kW single-phase home — often G98/NI if type-tested and within 16 A per phase (£0 application fee).
- Larger domestic (e.g. 5–10 kWp) with export capped ~3.68 kW — frequently G99/NI Fast Track (£311 ex VAT CAF) or full G99 if criteria fail.
- Three-phase homes, farms, small commercial — G98 can stretch to ~11.04 kW. Beyond that, expect G99, CAF from the table above, and longer lead times.
- Batteries — parallel storage can change the route via aggregate registered capacity. Design solar and storage together. See whether a home battery is worth it in Northern Ireland.
Who files the paperwork?
You remain the generator. Suppliers pay for export; NIE Networks owns the connection process.
B9 Renewables handles NIE notifications and applications as part of a normal install. Ask any contractor which route applies before you sign.
| Step | Who usually does it |
|---|---|
| Choose G98 vs G99 | Installer / designer after survey |
| G98 Stage 1 notification | Installer (within 30 days of commissioning) |
| G98 Stage 2 / G99 / Fast Track application | Installer (consultant on larger sites) |
| Pay CAF / accept NIE quotation | Customer (generator) + installer as required |
| Export tariff with supplier | Customer (installer often helps) |
Lead-time honesty
If the design needs G99, put grid approval in the programme. Do not book scaffold and hope the letter arrives.
| Route | What to plan for |
|---|---|
| G98/NI Stage 1 | Install first when eligible, notify within 30 days. Metering / supplier export can still add time. Application fee £0. |
| G98/NI Stage 2 | Network assessment first; timescale depends on size/volume. Submit fee £0; reinforcement may still apply if required. |
| G99/NI Fast Track | Approval before install. Licence standard: offer within 3 months of valid app + fee. Installer-reported ~20 working days once valid (not an NIE FAQ guarantee). Accept offer within 90 days. |
| Full G99/NI | Offer within 3 months of valid app (UR may extend). Wayleaves, planning milestones and reinforcement can add more. Accept within 90 days. |
Commercial and farm note
- Export may be constrained even if roof space is not.
- NIE CAF / possible reinforcement sit outside panel price — see how much solar panels cost in Northern Ireland.
- Agreements, milestones and queue position matter more than on a simple G98 house job.
- Export income is still voluntary supplier tariffs, not SEG — model self-use first.
Money and support (separate from grid forms)
- No SEG in NI — grid approval is not a GB-style export scheme.
- Export signup follows NIE steps — see solar export payments in Northern Ireland.
- Grants/VAT are separate — see solar panel grants and support in Northern Ireland. Eligible domestic installs may attract 0% VAT until 31 March 2027 (5% after that, unless extended); that does not change which grid form you need.
Sources
Frequently asked questions
Does Northern Ireland use G98 or G99 for solar installs?
Northern Ireland uses its own versions, G98/NI and G99/NI, both run by NIE Networks. G98/NI is the fit-and-inform route for small systems, and G99/NI needs approval before installation. Be careful with Great Britain articles, which describe different rules and fees.
What size of system can use G98 in Northern Ireland?
G98/NI applies to type-tested equipment exporting up to 3.68 kW on single-phase, or about 11.04 kW on three-phase (16 A per phase). Existing generation at the property counts, so confirm the route for your kit with your installer.
Is there a G98 application fee?
No. The submit fee is £0 for G98/NI Stage 1 and Stage 2. Network reinforcement costs can still apply after a Stage 2 study.
What does a G99/NI Fast Track application cost?
The Schedule 2 connection application fee is £311 ex VAT (£373.20 inc. 20% VAT) under NIE Networks Statement of Connection Charges V1.16, in force from 1 July 2026.
Can I install solar panels before NIE Networks approves a G99 application?
No. G99/NI needs NIE Networks approval before installation. G98/NI is different: your installer fits the system first and notifies NIE Networks within 30 days of commissioning.
Does a bigger solar array mean I can export more?
Not necessarily. Under the published G99/NI Fast Track criteria, export is still capped at 16 A per phase (about 3.68 kW), and many larger systems are export-limited, often using G100 export limitation. A bigger array mostly increases what you can use at home.
How long does a G99/NI application take?
Licence standard: connection offer within 3 months of a valid application and fee. Fast Track jobs often move faster in practice (~20 working days once valid — installer-reported). Full G99 can still stretch with studies and reinforcement.
Does adding a battery change whether I need G98 or G99?
It can. A battery installed alongside solar can add to the registered capacity NIE Networks counts, which can move a system from G98/NI into G99/NI. Design solar and storage together and confirm the route before you order.