Updated 26 September 2026. Source: DESNZ, Solar PV cost data 2025/26 (declared net capacity basis), published 28 May 2026.
Solar panel cost per kW in 2026
The Department for Energy Security and Net Zero publishes installed costs for every MCS-certified solar PV system in Great Britain each year. These are the 2025/26 figures, per kW of declared net capacity:
| System size | Median cost per kW | Mean cost per kW |
|---|---|---|
| 0–4 kW | £1,780 | £2,008 |
| 4–10 kW | £1,697 | £1,770 |
| 10–50 kW | £1,262 | £1,344 |
| 10–50 kW, non-domestic only | — | £1,259 |
Source: DESNZ, Solar PV cost data 2025/26 (April 2025 to March 2026), declared net capacity basis. MCS-certified installations in Great Britain; costs include VAT where applicable and exclude batteries or other devices installed with the panels.
Two things stand out for farms. Cost per kW falls sharply with size — a 10–50 kW system costs about 29% less per kW than a 0–4 kW domestic-sized one — and the statistics stop at 50 kW, which is where many farm arrays start.
What a farm solar system costs by size
Applying the band medians to typical farm sizes gives a first budget figure before any quote:
| System | Cost at the median | Basis |
|---|---|---|
| 10 kW | £17,000 | 4–10 kW band median |
| 20 kW | £25,200 | 10–50 kW band median |
| 30 kW | £37,900 | 10–50 kW band median |
| 40 kW | £50,500 | 10–50 kW band median |
| 50 kW | £63,100 | 10–50 kW band median |
For arrays above 50 kW there is no government benchmark. Ask for itemised quotes — panels, inverters, mounting, electrical works, the grid connection and any roof work as separate lines — and compare the cost per kW between them. Our ground-mounted solar guide covers the extra lines a field array adds.
How solar costs have moved since 2013
| 2013/14 | 2016/17 | 2020/21 | 2022/23 | 2023/24 | 2024/25 | 2025/26 |
|---|---|---|---|---|---|---|
| £1,332 | £1,150 | £1,000 | £1,232 | £1,375 | £1,257 | £1,262 |
Median installed cost per kW for 10–50 kW systems, nominal prices. Source: DESNZ, Solar PV cost data, Summary table.
The median fell through the late 2010s to a low of £1,000 per kW in 2020/21, rose to £1,375 in 2023/24 and has eased since. In real terms — DESNZ also publishes an inflation-adjusted series — the 2025/26 median is about a third below where it stood in 2013/14.
Farm solar cost by region
Mean cost per kW for 10–50 kW systems in 2025/26, with the number of installations DESNZ analysed in each region:
| Region | Mean cost per kW (10–50 kW) | Installations analysed |
|---|---|---|
| North East | £1,234 | 284 |
| London | £1,247 | 567 |
| East of England | £1,306 | 1,457 |
| West Midlands | £1,316 | 757 |
| East Midlands | £1,330 | 878 |
| North West | £1,347 | 815 |
| Yorkshire and The Humber | £1,347 | 789 |
| Wales | £1,362 | 538 |
| South West | £1,369 | 1,138 |
| Scotland | £1,387 | 603 |
| South East | £1,409 | 1,735 |
Source: DESNZ, Solar PV cost data 2025/26, Regional costs sheet. Great Britain only; Northern Ireland is not included.
What changes the price on a farm
- • The roof. Modern profiled-steel sheds are straightforward; asbestos cement sheeting has to be overclad or replaced before panels go on — see solar panels on asbestos roofs.
- • The structure. Older frames and purlins may need a structural check or strengthening before they carry an array.
- • Distance to the supply point. A shed a long way from the meter or transformer means longer cable runs and trenching.
- • The grid connection. Most farm systems need a G99 application, and some need network reinforcement; see G98 and G99 explained.
- • The panels. Modules on or near livestock housing should carry ammonia-resistance certification; see choosing agricultural solar panels.
- • Batteries. Not included in the government figures; price any battery as a separate line.
The payback maths — a worked example
A modelled example, not a client install. A 40 kW array on a south-facing 30° roof near Shrewsbury generates about 38,520 kWh a year (PVGIS: 963 kWh per kWp). At the DESNZ median it costs about £50,500. Assume the farm uses 80% of the output itself and exports the rest at 5p/kWh. The grid price you avoid decides the payback:
| Grid price you avoid | Annual saving + export | Simple payback |
|---|---|---|
| 20p/kWh | about £6,550 | about 7.7 years |
| 25p/kWh | about £8,090 | about 6.2 years |
| 30p/kWh | about £9,630 | about 5.2 years |
Payback before tax relief. Replace the assumptions with your own tariff and half-hourly meter data; a farm that uses less of its output in daylight exports more at the lower rate and pays back more slowly. For how output varies through the year, see whether solar panels can power a whole farm.
Paying for it: tax, grants and rates
- • Capital allowances. Solar panels are special rate expenditure under section 104A(1)(g) of the Capital Allowances Act 2001. The £1m Annual Investment Allowance can relieve the full cost in the year of purchase for most farm businesses; companies can instead claim the 50% first-year allowance on new and unused special-rate assets. Full expensing does not cover solar.
- • Grants. England's Improving Farm Productivity grant (25% of eligible costs on rooftop and reservoir solar) has closed its second round; Wales, Scotland and Northern Ireland run their own schemes. See farm solar grants.
- • Business rates. Solar plant is excepted from rateable value in England until 1 April 2035 where most of the power is used on the premises. See farm solar and business rates.
- • Finance. Asset finance and power purchase agreements avoid the upfront cost; see farm solar finance options.
How to compare farm solar quotes
- Check each quote's cost per kW against the DESNZ benchmark for its size band — well above it, ask why; well below it, check the equipment and warranties.
- Make sure the size is justified from your half-hourly meter data, not the size of the roof.
- Ask for the grid application, any roof work and the monitoring to be priced as separate lines.
- Compare product, performance and workmanship warranties in writing.
- Ask for a yield estimate for your roof and location, and the assumptions behind any payback figure.