DNO grid connection for rural UK farm solar in 2026

The Distribution Network Operator (DNO) connection process is the single longest item in most UK farm solar project timelines. Understanding how G99 works, which DNO covers your area, what timelines to expect, and how to design around capacity constraints will save months and tens of thousands of pounds on a typical install. Here’s the 2026 picture for rural UK farms.

The six UK DNOs and their rural coverage

The UK distribution network is operated by six DNO groups: National Grid Electricity Distribution (covering the Midlands and South Wales, formerly Western Power Distribution); UK Power Networks (London, South East, East Anglia); Northern Powergrid (Yorkshire and North East); Electricity North West (Greater Manchester, Lancashire, Cumbria); Scottish Power Energy Networks (Cheshire, Merseyside, North Wales); and SSEN — Scottish and Southern Electricity Networks (Southern England plus North Scotland and the Highlands). Each DNO has different rural feeder capacity profiles, different G99 application portals, and different connection charging policies. For farm solar projects, the DNO covering your specific feeder typically determines your timeline more than any other factor.

What G99 actually is and when it applies

G99 is the Engineering Recommendation that governs how generation connects to UK distribution networks above 16A per phase (about 17 kW total at 240V). Almost every commercial farm PV install requires G99 application — only sub-17 kW systems can connect under the simpler G98 process. G99 application requires: system specification including panels, inverters, and protection; single-line electrical diagram; structural certification; site address and grid reference; existing supply details (MPAN, capacity, phase configuration); and any specific export/import constraints. Some DNOs require additional information for large installs (above 250 kW typically): grid-code compliance certificates, fault-level study, harmonic distortion analysis.

Typical 2026 connection timelines

G99 timelines have been deteriorating across most UK DNOs since 2023 as renewable connection demand has outpaced network capacity. As of early 2026, typical timelines on most rural feeders are: 65–90 working days for the technical study response; an additional 6–14 months for actual connection on capacity-constrained networks; 12–18 months for export-capacity reinforcement where the existing feeder cannot accommodate the full system. For systems above 1 MW, total timelines often run 18–24 months from G99 submission to commissioning.

Capacity-constrained networks and no-export design

Several rural networks across the UK currently have effectively zero export capacity for new generation — particularly in West Wales, the Highland and Islands, parts of Cornwall and Devon, and some Yorkshire Dales feeders. For sites in these areas, “no-export” design is the rational workaround. The system is sized for 100% self-consumption — meaning the inverters export zero generation to the grid at any moment. This requires real-time inverter control (typically via a power-export limiter or smart inverter management system), smaller system size (matched to instantaneous on-farm baseload rather than total annual demand), and acceptance of the lower SEG income that comes with no-export operation. The benefit: connection can complete in 6–8 weeks rather than 18 months, because the DNO has no network reinforcement to plan or fund.

Submitting G99 early to start the clock

For any farm project, the single most impactful timeline decision is when to submit the G99 application. We submit immediately after the structural survey — typically 3–4 weeks after contract signature. Some installers wait until full design completion before submitting; this loses 8–12 weeks of clock time unnecessarily. The G99 application can be updated as design firms up — what matters is registering the application with the DNO as early as possible to secure your position in the queue.

Connection charges and what to expect

DNO connection charges vary substantially by system size and required network works. For a 100 kW farm install on a typical rural feeder with available capacity, expect £4,000–£8,000 of DNO charges (study, contestable works, metering). For a 250 kW install, £8,000–£25,000. For a 500 kW–1 MW install with substantial contestable works, £25,000–£80,000+. Substation reinforcement (if required) can run £100,000–£500,000+ — at which point ground-mount lease to a third-party developer (who bears the connection capex) often becomes more economic than direct installation.

Negotiating with the DNO

DNO charges are not always fixed. Most DNOs will accept alternative connection arrangements (e.g., reduced export capacity, no-export design, staged commissioning) that reduce contestable works. We negotiate with DNO grid teams on every project to ensure the most cost-effective connection scope. For sites where the initial DNO quote is uneconomic, we explore: reducing system capacity to fit within existing feeder limits; no-export design eliminating export reinforcement; battery storage to absorb peak generation that would otherwise drive reinforcement; staged commissioning where Phase 1 connects under existing capacity and Phase 2 connects when network reinforcement completes.

What this means for your project

Plan the DNO timeline as the binding constraint on overall project delivery. For most farm rooftop projects, expect 6–14 months between contract and commissioning regardless of how fast the physical install can be completed. For ground-mount above 250 kW or any project on capacity-constrained networks, 12–24 months total is typical. Submit G99 early. Consider no-export design where export capacity is the binding constraint. And factor connection costs into your business case at the feasibility stage — they’re a real and increasingly material component of total project cost.