A typical 4kWp solar PV system costs roughly £5,500 to £8,000 installed in the UK in 2026. It suits most roofs that face east, south or west with little shade. You are paid for exported power through a Smart Export Guarantee tariff, which needs an MCS-certified system up to 50kW.
Most pitched-roof systems are permitted development in England, but the rules were amended on 27 August 2026 and conditions still apply, particularly for listed buildings and conservation areas.
How solar PV works
Solar photovoltaic (PV) panels turn daylight into direct current electricity. An inverter converts it to the alternating current your home uses. What you generate is used first in the house, any surplus is exported to the grid, and a battery can store some of the surplus for the evening.
System size is quoted in kilowatts peak (kWp). A 4kWp system is typically around 9 to 10 panels and suits many three-bedroom homes. Output depends on orientation, pitch, shading and location. See MCS for how systems are certified.
Is your roof suitable?
- Orientation: south is best, east and west are both worthwhile, and north-facing roofs are rarely worth it.
- Pitch: a pitch of about 30 to 40 degrees is ideal, but flatter and steeper roofs still work with mounting frames.
- Shading: chimneys, trees and neighbouring buildings can cut output sharply. Optimisers or microinverters can reduce the effect.
- Roof condition: if the roof needs work within about 10 years, do it first or at the same time. Re-roofing later means taking the array off.
- Structure: your installer should check the roof can carry the extra load, especially on older timber roofs.
- Scaffolding: a scaffold is a real part of the cost and safety plan. Sharing it with other roof work saves money.
Sizing a system
Size to your usage and roof space, not to the biggest system that fits. A larger array costs less per kWp but exports more of its output at a lower export rate. Use our Solar PV Calculator for an initial estimate, then ask installers to model your actual usage.
What does solar PV cost?
| Item | Indicative installed cost (2026) |
|---|---|
| 4kWp system | About £5,500 to £8,000 (roughly £1,400 to £2,000 per kWp) |
| Government and MCS data | Median figures for a 4kW system have been reported at about £7,500 |
| Battery (5 to 13kWh) | About £4,000 to £9,000 installed, if added at the same time |
| Scaffold, if separate | Often several hundred pounds, depending on the house |
These are ranges from MCS and DESNZ-derived data and installer price guides, which do not all agree. Quotes vary by roof, panel and inverter choice, and region. Treat any figure as a starting point for comparing quotes.
Savings and payback
The Ofgem price cap averages about 26.3p per kWh for electricity from October to December 2026. Every kWh you use from your own panels avoids that cost, while exported kWh earn only the export rate. Self-consumption is therefore worth far more than export.
A simple payback is the installed cost divided by the yearly saving plus export income. Payback varies widely with system size, how much you use during the day and your tariff, so work it through with your own usage rather than relying on a headline number.
Batteries
For a full breakdown, see our battery storage guide. Charging an electric car from solar is covered in the EV charging guide.
A battery stores surplus generation for use later, raising your self-consumption. Reported installed prices run from roughly £4,000 to £9,000 depending on capacity and brand, and simple payback is often quoted at 10 years or more unless you use time-of-use tariffs. Batteries tend to make most sense for households that are out in the day and use most power in the evening. Standalone home battery installs are currently zero-rated for VAT until 31 March 2027, after which the 5% reduced rate is due to apply unless the relief is extended.
Getting paid for exports: the Smart Export Guarantee
The Smart Export Guarantee (SEG) requires larger suppliers to offer a tariff for exported electricity. Rates vary a lot, from a few pence per kWh up to higher rates on tariffs tied to a supplier's import tariff or battery. One widely available open tariff pays 12p per kWh at the time of writing, and some bundled tariffs pay more. Rates change often and sources disagree, so compare current offers on supplier sites. For systems up to 50kW you will need an MCS-certified system and installer. See the MCS certification guide.
Planning permission and permitted development
In England, solar panels on a house are generally permitted development, subject to conditions. Long-standing conditions included panels not protruding more than 200mm from the roof and not rising above the highest part of the roof, and extra limits in conservation areas. Listed buildings always need listed building consent.
The government amended the permitted development rules for domestic solar, with changes in force from 27 August 2026. They treat houses and blocks of flats separately, clarify plug-in solar and allow projects that would no longer qualify to use the old rules until 26 August 2027. Because the detail is new, read the current rules on the Planning Portal and check with your council. For listed buildings, see solar panels on listed buildings. Scotland, Wales and Northern Ireland have different rules.
Grid connection, electrical work and Building Regulations
- Notifying the network operator: small systems up to 16A per phase (about 3.68kW on a single-phase supply) are normally notified under G98, within 28 days of commissioning. Larger systems need approval under G99 before installation. Your installer normally handles this.
- Batteries count: adding an AC-coupled battery can push a site over the G98 limit, so tell your installer you plan one.
- Electrical safety: the work is notifiable under Part P. An installer registered with a competent person scheme can self-certify.
- Structure and fire: check roof loading and cable routes. Your installer or building control should confirm.
Choosing an installer
- Choose an MCS-certified installer that is a member of a consumer code, and check the MCS directory yourself.
- Get at least three written quotes, each showing panel and inverter models, system size in kWp, expected annual generation, and warranties.
- Be wary of high-pressure sales, unrealistic payback claims and requests for large upfront deposits.
- Ask who handles the DNO notification, the MCS certificate and the SEG paperwork.
- Keep the MCS certificate and Building Regulations compliance certificate for the sale of the property.
See our solar PV installer page for what installers do and typical qualifications.
Sources and further reading
- Planning Portal: changes to permitted development for domestic solar The August 2026 rule changes in England
- Planning Portal: solar panels Planning guidance for solar panels
- Ofgem: energy price cap and standing charges Electricity unit rates and standing charges
- MCS: the quality mark for small-scale renewables Certification and the installer directory
- HMRC: VAT rates for energy-saving materials (VENSAV2083) Zero rate dates for batteries and heat pumps
External links open in a new tab. Last checked October 2026.
Frequently asked questions
How much do solar panels cost in the UK in 2026?
A typical 4kWp system costs roughly 5,500 to 8,000 pounds installed, or about 1,400 to 2,000 pounds per kWp. Government and MCS median figures have been reported higher at about 7,500 pounds, so compare written quotes.
Do I need planning permission for solar panels?
Roof-mounted panels on a house in England are generally permitted development, subject to conditions, but the rules were amended from 27 August 2026. Listed buildings always need consent. Check the Planning Portal and your council.
What is the Smart Export Guarantee?
It is a scheme under which larger electricity suppliers pay you for surplus electricity you export. Rates vary by supplier, and systems up to 50kW generally need to be MCS certified.
Is a solar battery worth it?
It depends on how much of your power you use in the evening and whether you have a time-of-use tariff. Simple payback is often quoted at 10 years or more, so model it with your own usage.
Do I need to tell my network operator about solar panels?
Yes. Small systems are notified under G98 within 28 days of commissioning, and larger ones need approval under G99 first. Your installer normally handles this.