A large UK solar farm costs roughly £530,000 to £790,000 per MW to develop and build, according to a government cost study. The middle estimate is about £660,000 per MW. Here’s where the money goes, in plain English.
The headline figures
The government’s latest cost study (by Arup for DESNZ, published July 2025) looked at solar farms over 5MW. All figures are per MW of panels (MWp), in 2023 prices.
| Cost | Low | Middle | High |
|---|---|---|---|
| Development (surveys, planning, grid application) | £12,000 | £24,000 | £59,000 |
| Construction (panels, inverters, frames, cabling, fencing) | £423,000 | £522,000 | £601,000 |
| Grid connection and substation | £91,000 | £112,000 | £129,000 |
| Total | £526,000 | £659,000 | £788,000 |
Running costs
Once built, a solar farm costs around £6,500 to £12,300 per MW a year to run (middle estimate about £9,300). That covers:
- Operations and maintenance: cleaning, repairs, monitoring, grass cutting or grazing.
- Insurance.
- Grid charges for using the network.
The study doesn’t include land rent. That is usually around £1,000 per acre a year. New solar farms need roughly 2 to 4 acres per MW, so rent adds about £2,000 to £4,000 per MW a year. See solar farm rent per acre.
A worked example: a 20MW solar farm
Using the middle figures from the study:
- Build cost: about £13.2 million (20 × £659,000).
- Running costs: about £186,000 a year, plus rent.
- Land: roughly 40 to 80 acres.
- Lifetime: 35 to 40 years.
This is a rough guide, not a quote. Every site is different.
What pushes the cost up or down
- The grid connection. This is the biggest swing. A long cable run, a new substation or upgrades to the local network can add a lot.
- Ground conditions. Soft or rocky ground changes the type of frame and piling needed.
- Site shape and access. Large, simple fields with good road access are cheaper to build on.
- Size. Fixed costs such as the substation, roads and CCTV are spread over more megawatts on a bigger site.
- Planning conditions. Screening, landscaping and the 10% biodiversity gain all add cost.
- Equipment prices. Panel and inverter prices change with the global market.
- Battery storage. Adding a battery on the same site adds cost, but can add income too.
Development costs come first, and carry the most risk
Development is the smallest slice of the total, but it is spent before you know the site will work. Surveys, a planning application and a grid application all cost money, and some sites fail along the way. That is why ready-to-build sites sell for a premium. See how solar farms are valued.
What we do
We screen sites early with our own software, so you see grid, planning and yield before you spend on surveys. Our fixed fees show what each stage of development costs. Development to ready-to-build →
Sources
- DESNZ / Arup: Renewable Energy Generation Cost and Technical Assumptions 2024 (July 2025)
- Carbon Brief: is solar power a threat to UK farmland? (land use per MW)
Facts last checked 12 October 2026. Costs are in 2023 prices and will have moved since. This is general guidance, not a quote.