The grid connection is where farm solar projects most often stall. Rural networks were built to deliver electricity to farms, not to take large amounts back, and a big array at the end of a long line can hit the limits of the local network. None of that stops a project, but it decides its size, its cost and its timing — so it belongs at the start of planning, not the end.
G98 or G99 — which route is yours?
The Energy Networks Association's engineering recommendations set the threshold at 16 A per phase. Up to that, a system connects under G98: the installer fits and commissions type-tested equipment and then notifies the network operator. Above it, G99 applies: you apply first, the operator studies the network, and the system may only be connected once it has approved it. Batteries count — the operator looks at everything that can feed power onto its network, not just the panels.
Northern Ireland uses its own versions, G98/NI and G99/NI, run by NIE Networks. Since 1 May 2026 NIE has offered a G99/NI fast track for installations up to 60 A per phase with export held to 16 A per phase — but approval must still be granted before installation begins. Most farm systems will go through the full G99/NI process.
Who your network operator is
| Network operator | Licence areas |
|---|---|
| UK Power Networks | London, the South East and the East of England |
| National Grid Electricity Distribution | West Midlands, East Midlands, the South West and South Wales |
| SSEN | Central southern England and the north of Scotland |
| SP Energy Networks | Central and southern Scotland; Merseyside, Cheshire, north Wales and north Shropshire |
| Northern Powergrid | The North East, Yorkshire and northern Lincolnshire |
| Electricity North West | The North West of England |
| NIE Networks | Northern Ireland |
Licence-area boundaries do not follow county lines — check your operator by postcode before budgeting. Our regional farm solar guides list the operators in each area.
How a G99 application works
- Application. The installer (or you) sends the operator the system's size, the equipment and the connection point.
- Assessment. The operator checks the capacity of the local network for the power you want to export.
- Connection offer. It sets out any works needed, their cost and timescale, and any export limit — with a deadline to accept.
- Installation and commissioning. Only after acceptance; larger systems may need the operator to witness the tests.
- Final approval. The system can then run and export within the agreed limits.
Apply before you order equipment. A connection offer that comes back with reinforcement costs or a tight export limit may change the right size of array — and grant schemes, when they run, have not paid for anything ordered before approval.
Export limits: often cheaper than they sound
Where the network is constrained, the operator may offer a connection only with an export limit, controlled by a system built to the ENA's G100 guidance. It caps what leaves the site, not what the panels generate or what the farm uses. On a dairy, poultry or pig farm with high daytime demand, most of the output is used on site anyway, so an export limit can cost very little — and it can turn "no connection available" into a connection now. Check it against your half-hourly meter data before accepting.
Single-phase supplies
On a single-phase supply the G98 limit is 3.68 kW, so any farm-scale system is a G99 application. Some older farmsteads also need a supply upgrade before a larger array can connect; if so, the operator's quotation will say what it involves and costs. Knowing whether your holding has a three-phase supply — and its capacity — is one of the first things a feasibility study should establish.
Getting paid for exports
In Great Britain the Smart Export Guarantee pays for exported electricity at a rate each licensed supplier sets. For systems up to 50 kW, suppliers ask for MCS or an equivalent certification; from 50 kW to 5 MW, the installation must be certified to the supplier's satisfaction. Northern Ireland has no equivalent scheme. Either way, electricity used on the farm is usually worth several times what an export pays, which is why arrays are sized around daytime demand.
After connection
On rural lines, inverters sometimes trip when local voltage rises at times of high export; monitoring shows it, and the operator and installer can investigate — see what farm solar monitoring should show. Any later extension or battery changes what the operator approved: see upgrading an existing farm system. For costs, see what agricultural solar panels cost.
Grid connection — frequently asked questions
Do I need a G99 application for farm solar?
If the system is rated above 16 A per phase — 3.68 kW on a single-phase supply or about 11 kW on three-phase — yes. Smaller systems use the simpler G98 route, where the installer fits the system and then notifies the network operator. Almost every commercial farm system is above the G98 limit.
What is export limitation?
A control system that caps how much power the site can push onto the network, set out in the ENA's G100 guidance. It does not limit generation or self-use, so a farm with high daytime demand can often accept an export limit at little cost, and it can make a connection possible where the local network is constrained.
How long does a G99 connection take and what does it cost?
It depends on the network at your connection point. The operator's connection offer sets out the cost of any works and the timescale; a site where the network needs reinforcing costs more and takes longer than one with spare capacity. Apply early — before you order equipment.
Can I get paid for the electricity I export?
In Great Britain, yes, through the Smart Export Guarantee: each licensed supplier sets its own rate. For systems up to 50 kW suppliers ask for MCS or an equivalent certification; from 50 kW to 5 MW the installation must be certified to the supplier's satisfaction. Northern Ireland has no equivalent scheme.