Wolverhampton makes things, and factories that make things in daylight are the best case for rooftop solar in the West Midlands. This worked example takes a 50 kWp array on a typical Wolverhampton engineering or fabrication unit, the kind found on the Neachells Lane estates in Wednesfield or around Springvale in Bilston, and runs it on official figures only. The short version: the array costs about £61,650 and is worth between about £6,350 and £10,960 a year, depending almost entirely on how many shifts you run. The detail for the city is on our commercial solar Wolverhampton page.
Step one: what 50 kWp makes in Wolverhampton
PVGIS, the European Commission’s solar yield model, puts a south-facing array at 35 degrees in Wolverhampton at 956 kWh per kWp a year with 14% system losses. A 50 kWp array therefore generates about 47,800 kWh a year. East-west layouts on a low-pitched steel roof make a little less per panel but spread generation across the morning and afternoon, which can suit a shift pattern better than a midday peak.
As a rule of thumb each kWp needs around 6 to 8 m² of clear, well-oriented roof, so 50 kWp needs about 300 to 400 m². Most portal-frame units on the city’s industrial estates have that several times over.
Step two: what it costs
The Department for Energy Security and Net Zero records the total installed cost of every MCS-certified solar system. For the West Midlands in 2025/26 the mean was £1,233 per kW for 10 to 50 kW systems, across 1,181 installations. At that rate 50 kWp is about £61,650 as an average job. It is a mean, not a quote: what moves the price on a Wolverhampton roof is the roof itself, such as the fixing system for the sheet profile, any structural strengthening on an older frame, and the cable run to the main switchroom.
Step three: what it is worth on each shift pattern
Solar saves money when you use the power on site, because each unit displaces one you would otherwise buy. DESNZ’s quarterly energy prices put the UK average non-domestic electricity price for January to March 2026 at 24.14p per kWh including the Climate Change Levy. The variable is how much of the 47,800 kWh you use yourself.
| Shift pattern | Share used on site | kWh used on site | Value a year at 24.14p | Value a year at 17.5p | Simple payback at 24.14p |
|---|---|---|---|---|---|
| Single day shift, Monday to Friday | 55% | 26,290 | about £6,350 | about £4,600 | about 9.7 years |
| Two shifts, Monday to Friday | 80% | 38,240 | about £9,230 | about £6,690 | about 6.7 years |
| Round the clock, seven days | 95% | 45,410 | about £10,960 | about £7,950 | about 5.6 years |
The shares are modelling assumptions, not measurements: your half-hourly data replaces them. Export earnings are left out, which makes every payback figure slightly pessimistic.
Why weekends decide the single-shift case
A single-shift plant that closes on Friday afternoon still has an array generating on Saturday and Sunday, and in summer those are some of the best days of the year. That weekend output is exported or wasted, which is why the single-shift case sits well behind the others. Two fixes work: size the array to the weekday load rather than the roof, or move a flexible load such as compressed air, curing ovens or forklift charging into the generating window.
The price you pay changes the answer
The 24.14p figure is an average across every size of non-domestic customer. Large energy users negotiate lower rates: DESNZ put the manufacturing average at 17.5p per kWh excluding the Climate Change Levy, and the table shows what that does to each case. A business on a fixed contract signed in a high-price year may be paying more than the average. The honest approach is to take your own unit rate from your latest bill and multiply.
Tax: the Annual Investment Allowance
Solar panels are special-rate plant. The £1m Annual Investment Allowance usually means 100% relief in year one for a business under the limit, so the whole £61,650 can be set against profits in the year of purchase. Above the limit, companies can claim a 50% first-year allowance on special-rate plant. Full expensing is for main-rate plant and does not cover solar. The worked numbers are in our commercial solar capital allowances guide.
Business rates and VAT
Onsite renewable generation and battery storage are left out of business-rates valuations in England from 1 April 2022 to 31 March 2035, so the array does not raise the unit’s rateable value. On a factory the installation is standard-rated for VAT at 20%; the 0% rate covers homes and some charitable buildings. A VAT-registered business normally recovers it.
Getting connected to the grid
A 50 kWp system is well above the 16 A per phase limit for the simple notify-after process, so it needs a G99 application and the network operator’s approval before it connects. Wolverhampton is in National Grid Electricity Distribution’s West Midlands licence area. Build the approval time into the programme: the application goes in at design stage, before panels are ordered.
Planning on a Wolverhampton industrial estate
Rooftop solar on a non-domestic building in England is permitted development under Class J of Part 14 of the General Permitted Development Order. Up to 50 kW counts as microgeneration. Above 50 kW on a roof, the council’s prior-approval decision on design and external appearance, including glare, is needed before work starts. The panels must stay at least 1 m in from the roof edge, and listed buildings need full consent. The rules are set out on our commercial solar planning permission page. Leased units add a separate question: the landlord’s consent under the lease, which sits outside planning altogether.
Where a battery fits
On a two-shift or round-the-clock site, almost all the generation is used as it is made, and a battery adds little. On a single-shift site, a battery can carry afternoon generation into the late shift or the next morning, which lifts the share used on site. Whether it pays depends on the battery’s cost against the extra units it saves, so it is a separate calculation; battery storage for business explains how we run it.
What would make the numbers worse
Three things. A roof that needs repair within the array’s life: fix it first, because lifting and relaying panels costs money. Shading from neighbouring buildings, plant or rooflights, which PVGIS does not model. And a lease with only a few years left, where the business pays for an asset it may leave behind.
The next step
The sums above are the official averages. Your own version needs three numbers: your half-hourly consumption, your unit rate and your usable roof area. Factories across the Black Country follow the same arithmetic, and our solar panels for factories page covers the sector; neighbouring sites are on our commercial solar Walsall and commercial solar Dudley pages.
Sources
- Yield: European Commission JRC, PVGIS 5.3 (SARAH3), Wolverhampton, south-facing at 35 degrees, 14% system loss: re.jrc.ec.europa.eu/pvg_tools/en/
- Costs: DESNZ, Solar PV cost data, 2025/26 Total Installed Cost workbook, “Regional costs (TIC)”, West Midlands: gov.uk/government/statistics/solar-pv-cost-data
- Grid prices: DESNZ, Quarterly Energy Prices, June 2026 release (January to March 2026): gov.uk/government/collections/quarterly-energy-prices
- Capital allowances: HMRC HS252 and gov.uk guidance on first-year allowances for plant and machinery
- Rateable value exclusion to 31 March 2035: S.I. 2022/405
- VAT on energy-saving materials: HMRC VAT Notice 708/6
- Permitted development, Class J: GPDO 2015, Schedule 2, Part 14