Vertical solar
Wall-mounted and vertical solar panel calculator
A sunny wall can carry a proper solar array when the roof can't. Panels on a wall stand upright, so they make less than a roof over the year and more of it in winter. Give us the wall space, the way it faces and what stands in front of it, and we work out what an installed array would make, save and cost.
Last updated 2 November 2026.
What would an array on this wall make?
Give the clear wall space, the way it faces and what stands in front of it. Add your postcode for your own area's sun and the installers who cover it.
Know the height and distance?
Estimated generation
580–700 kWh/year
2 panels (0.88 kWp), facing south, open sky.
Annual saving
£65–£135
A year, bill savings plus export
Install cost
£2,035–£2,710
Typical installed price
Payback
19–28.5yrs
Before it pays for itself
CO₂ saved
≈ 113kg
A year, against grid electricity
About 73%
of what the same panels would make on a pitched south roof. Upright panels miss the high summer sun.
About 41%
of its energy comes October to March, when the low sun hits an upright panel square on. A pitched roof: about 32%.
How that adds up
- Used at home, about 35%
- 200–250 kWh
- Exported, the rest
- 370–460 kWh
- Bill savings
- £50–£75/yr
- Export income
- £20–£60/yr
At 0.88 kWp this connects on a G98 notification the installer files after fitting. No wait for approval.
Climate data from PVGIS for typical UK (Birmingham), on a panel fixed upright facing south with open sky. UK 2026 prices. Estimates to plan around; an installer survey confirms the figures for your wall. How we measure.
Month by month
How an upright array on this wall generates across the year. Flatter than a roof: the low winter sun suits it.
Most generation lands in the brighter months (highlighted). A system is sized for the whole year, not just summer. Estimated from PVGIS climate data for your postcode area — a roof survey confirms your exact figure.
Solar resource data: © European Union, 2025, PVGIS, EU Science Hub.
Before you book
What to check on a wall-mounted array.
- How far it sticks out. Permitted development in England allows a wall array to project up to 0.4 m from the wall, or 0.2 m where the wall faces a highway. Listed buildings need consent, and in a conservation area a wall facing a highway needs permission.
- An MCS installer. The certificate is what unlocks the Smart Export Guarantee and the warranties. Every installer listed here holds one.
- Grid connection. Up to 3.68 kW on a single phase connects on a G98 notification; above that the installer applies under G99 before fitting.
- The wall itself. Fixings into solid masonry, the frame's wind load, and anything the panels would cover: vents, meters, windows, downpipes.
- Whose wall it is. Leaseholders need the freeholder's written consent; a party wall needs the neighbour's.
- A survey confirms it. The figures above are estimates from the climate record. An installer's survey gives the confirmed price and output for this wall.
How it works
What this calculator works out.
Generation on an upright panel
The sun on a panel fixed at 90° facing your wall's direction, from the PVGIS climate record for your postcode area, with the sky in front of it blocked as high as you said. A south wall makes about 70–75% of a pitched south roof over the year; east and west walls about half.
Panels that fit
We lay standard panels across the clear wall, upright or on their side, whichever fits more, with 0.3 m kept clear at each edge. Measure round windows and vents, not the whole elevation.
Saving
Solar you use at home instead of buying, up to what your home actually uses by day, plus export income on the rest. A battery moves more of it into the evening.
Payback
Installed cost divided by the annual saving, as a range. A sunny south wall pays back within the panels' life; a shaded or north-facing one may never.
The figures behind it
2026 assumptions.
Panels
440 W each, 1.134 m by 1.762 m
A standard module. We count how many fit the clear wall with 0.3 m kept at each edge, up to 20.
Install cost
£1,000 + £1,150–£1,900 per kWp
An MCS installer, the frame, the inverter and the connection paperwork. Scaffolding on a tall wall can add to it.
Battery
£3,000–£6,000
Optional. Stores daytime power for the evening, so more of what the wall makes is used at home.
Electricity price
24–30p per kWh
Low end tracks the Ofgem price cap; high end covers non-direct-debit and regional spread.
Export payment
5–13p per kWh
Smart Export Guarantee rates on what the array sends to the grid. The MCS certificate is what qualifies you.
Grid connection
G98 up to 3.68 kW, G99 above
The single-phase limit for connecting first and notifying after. Larger arrays need the network operator’s approval before fitting.
Shade
0°, 10°, 25° or 40° of sky blocked
How high what stands in front of the wall reaches above the horizon. Type a height and distance for your own figure. Applied across the sky the wall looks at.
Grid carbon
0.177 kg CO₂ per kWh
UK electricity generation factor, DESNZ 2025.
Is the roof an option too?
Check your own roof.
Enter your property number and postcode today, and we'll read your roof from the sky to get a better understanding of whether or not your roof is suitable for solar panels. Free, takes minutes, and no account necessary.
Common questions
Wall-mounted solar, answered.
Are wall-mounted solar panels worth it in the UK?
On a sunny, unshaded wall, often yes. A south-facing wall makes about 70–75% of what the same panels would on a pitched south roof, and an east or west wall about half. The panels cost the same, so payback is longer than a roof, but a wall is the answer when the roof is shaded, too small, listed or shared. The calculator shows the payback range for your own wall.
Why do vertical solar panels make more of their energy in winter?
An upright panel faces the low winter sun square on and catches the high summer sun at a glancing angle, so its output is flatter across the year than a pitched roof’s. In London a south wall makes around 40–45% of its energy between October and March, against about a third for a roof at 40°. It makes less over the whole year, but more of it lands when bills are highest.
Do I need planning permission for solar panels on a wall?
Usually not in England. Since 27 August 2026, wall-mounted panels on a house are permitted development if they stick out no more than 0.4 m from the wall, or 0.2 m where the wall faces a highway. Listed buildings need consent, and in a conservation area panels on a wall facing a highway need permission. Scotland, Wales and Northern Ireland have their own rules, and your installer will check them at the survey.
Can I get paid for what a wall-mounted array exports?
Yes. Fitted by an MCS-certified installer, a wall array qualifies for the Smart Export Guarantee like any rooftop system, so every kWh it sends to the grid earns an export rate. The calculator adds that income to the bill saving.
Which way should the wall face?
South is best, then south-east and south-west, which give up only a little. East and west walls make roughly two-thirds of a south wall and suit a home that uses power in the morning or evening. North-facing walls get little direct sun in Britain and rarely pay back.
Is a wall array different from a plug-in kit?
Yes. A plug-in kit is capped at 800 W through a socket, needs no electrician and earns nothing for what it exports. A wall-mounted array has no such cap, is fitted and certified by an MCS installer, and earns export payments. If you only have a balcony or a few square metres, our plug-in solar calculator is the better fit.
