Every farm solar project follows the same broad timeline from contract signature to commissioning. Specifics vary by system size, roof condition, planning context, and DNO capacity, but the structure is consistent. Here's what to expect from a typical 200 kW farm install in 2026.
Weeks 1-2: Contract execution and project mobilisation
Contract signature triggers the formal project mobilisation. We assign a project manager, schedule the kick-off meeting (typically week 1, on-site or video), confirm the detailed scope, agree any final design adjustments, and lock in the fixed price. The kick-off meeting walks through the full programme, identifies key project decisions (final panel and inverter selection, integration with farm operations, biosecurity protocols for poultry/pig installs), and agrees the communication cadence.
Weeks 2-4: DNO G99 application + structural design
We submit the G99 grid connection application to the regional DNO within 14 days of contract signature. The G99 study response typically arrives 65-90 working days later. In parallel: detailed structural design completes, including any reinforcement calculations; final electrical design completes (string sizing, inverter selection, protection equipment); procurement specification firms up. For combined re-roof + PV installs, the asbestos contractor submits the Asbestos Removal Notification to HSE (14-day notice required).
Weeks 4-12: Planning consultation (if required)
Most rooftop installs on agricultural buildings are Permitted Development under Class A Part 14 GPDO 2015 — no planning permission required. Where planning is needed (listed buildings, AONBs with Article 4 directions, large ground-mount, Conservation Areas), we lodge the application during weeks 4-6 and engage with the planning authority and conservation officer through weeks 6-12. Typical planning timeline: 8-14 weeks from submission to consent.
Weeks 8-16: Procurement and equipment delivery
Panel and inverter procurement starts immediately after detailed design completion (typically week 4-6). UK distributor lead times in 2026 average 4-8 weeks for standard tier-1 modules (JA Solar, LONGi, Jinko) and 3-6 weeks for inverters (Huawei, SolarEdge, SMA). For installations above 500 kW, we coordinate phased delivery to match installation schedule. Racking, cabling, isolation equipment, monitoring hardware all ship in parallel.
Weeks 12-18: On-site installation
Physical installation begins after: G99 study response received and approved; structural design signed off; equipment delivered to site; access and biosecurity arrangements agreed with the farm manager; (for asbestos cement projects) asbestos removal completed and re-cladding installed. Typical install duration for a 200 kW system on a single building: 2-3 weeks. For multi-building 400-600 kW installs: 4-6 weeks. Working hours are typically Mon-Fri 08:00-17:00 with some Saturday work in summer; we work around the farming calendar avoiding calving, lambing, harvest, and shearing peaks.
Weeks 18-22: DNO connection works and commissioning
After physical installation completes, the DNO completes any contestable works (typically 2-6 weeks depending on network reinforcement requirements). Once DNO works are complete and the system is energised, commissioning testing follows: insulation resistance checks, polarity verification, RCD testing, MPPT and inverter functional checks, monitoring portal activation. MCS commissioning paperwork is submitted within 14 days of energisation.
Week 22-24: Handover and documentation
Final handover includes: MCS commercial certificate; structural and electrical certificates; building regulations approval where required; planning consent documentation; G99 acceptance letter; manufacturer warranties (panel, inverter, racking); IWA workmanship warranty certificate; complete electrical drawings (single-line, layout, schedules); operations manual; monitoring portal login and training; SEG application support documentation; supplier-audit support pack (if applicable).
Typical end-to-end timeline
Rooftop install on existing cladding (no re-roof): 5-7 months from contract to commissioning.
Combined re-roof + PV install: 6-9 months from contract to commissioning. Adds 6-12 weeks for asbestos removal and re-cladding.
Ground-mount above 250 kW: 12-18 months including full planning process.
Ground-mount above 1 MW: 18-24 months including planning, ecological survey, and DNO export reinforcement.
What can delay the timeline
In order of frequency: (1) DNO grid connection delays beyond 14 months (capacity-constrained networks); (2) planning consent delays beyond 12 weeks (listed buildings, AONBs); (3) procurement delays during high-demand periods (typically Q2-Q3 each year); (4) farm operational changes requiring rescheduling around revised calving/harvest dates; (5) weather delays during scaffolding-erection phase (rare but occasionally adds 1-2 weeks); (6) ASF or AI biosecurity restrictions on poultry/pig farms.
We set realistic expectations at contract signature. The fixed-price proposal includes a target commissioning date with a defined window for slippage. If any item starts moving outside the original timeline, we communicate immediately with revised forecast and recommended response.