Solar Panels for Your Home: Complete UK Guide
Everything you need to know about installing solar panels on your UK home — costs, savings, grants, and what to watch out for.
Solar Panel Costs by System Size (2025)
| Size | Panels | Cost | Annual Output | Annual Saving |
|---|
| 3 kW | 8–10 | £4,500 – £5,500 | 2,700 kWh | £450 – £550 |
| 4 kW | 10–12 | £6,000 – £7,000 | 3,600 kWh | £600 – £720 |
| 5 kW | 12–15 | £7,500 – £8,500 | 4,500 kWh | £750 – £900 |
| 6 kW | 15–18 | £9,000 – £10,000 | 5,400 kWh | £900 – £1,080 |
Costs include installation by an MCS-certified installer. Savings assume south-facing roof, 50% self-consumption, and 24.5p/kWh electricity rate.
How Much Can You Actually Save?
The amount you save depends on three things: how much electricity your panels generate, how much of it you use yourself, and what you get paid for exporting the surplus. A typical 4 kW south-facing system generates around 3,600 kWh per year. If you use half of that directly (displacing electricity at 24.5p/kWh) and export the rest at 15p/kWh through the Smart Export Guarantee, your total annual benefit is roughly £700. At a system cost of £6,500, that means a payback period of around nine years — with 16 years of pure profit after that, given panels are warranted for 25 years.
Your actual savings will vary based on roof orientation, shading, and how much electricity you use during daylight hours. Use our Solar Panel ROI Calculator for a personalised estimate.
Planning Permission
Solar panels are classified as permitted development in England, meaning you typically do not need planning permission. The main conditions are that panels must not protrude more than 200mm beyond the plane of the roof, and on a flat roof they must not sit higher than one metre above the highest part of the roof (excluding the chimney). If your home is a listed building or in a conservation area, you will need to apply for planning permission — your local authority can advise. In Scotland and Wales the rules are similar but check your council's specific guidance.
MCS Certification
MCS (Microgeneration Certification Scheme) certification is essential if you want to receive payments under the Smart Export Guarantee. Only MCS-certified installers can issue the certificate you need. MCS certification also gives you confidence that the installation meets industry standards for quality and safety. Always ask to see an installer's MCS registration number before agreeing to any work, and verify it on the MCS website. Non-certified installations may be cheaper, but you will miss out on export payments and may have difficulty selling your home if the installation does not meet building regulations.
Battery Storage: Pros and Cons
| Capacity | Typical Cost | Best For |
|---|
| 5 kWh | £2,500 – £3,500 | Small systems, low evening usage |
| 10 kWh | £4,000 – £5,500 | Most homes, 4 kW+ systems |
| 13 kWh | £5,500 – £7,500 | Large homes, high self-consumption |
Adding a battery lets you store solar energy generated during the day for use in the evening. Without a battery, a typical household uses about 50% of its solar generation directly. With a battery, this can rise to 80% or more, significantly increasing your savings. The downside is cost — a good home battery adds £3,000 to £6,000 to your installation. The payback on the battery alone is longer than on the panels, typically 8–12 years. However, batteries also provide resilience during power cuts (if configured for backup) and some tariffs let you charge from the grid overnight at cheap rates and discharge during peak hours.
Smart Export Guarantee (SEG)
The Smart Export Guarantee requires all licensed electricity suppliers with 150,000 or more customers to offer a tariff for exported solar electricity. To qualify, you need an MCS-certified system and a smart meter. Rates vary considerably between suppliers: the best SEG tariffs currently offer around 15p/kWh, while the worst pay as little as 1p/kWh. You are not tied to your electricity supplier for SEG payments — you can choose whichever supplier offers the best export rate. Some suppliers offer "agile" or time-of-use export tariffs that pay more during peak hours, which can be particularly attractive if you have a battery.
Government Grants and Support
The ECO4 scheme (Energy Company Obligation) provides funding for energy efficiency improvements including solar panels, primarily targeting low-income households and those on qualifying benefits. If you are eligible, ECO4 can cover the full cost of a solar installation. Outside ECO4, several local authorities run group buying schemes or direct grants for solar panels — these can reduce costs by 20–30%. The government has also set VAT at 0% for residential solar panel installations, saving you hundreds of pounds compared to the standard 20% rate. Check the government's Simple Energy Advice service and your local council's website for current schemes in your area.
Is It Worth It?
For most UK homeowners with a suitable roof, solar panels are a strong financial investment. With electricity prices at current levels and 0% VAT on installation, payback periods of 7–10 years are typical, followed by 15–18 years of essentially free electricity. Solar panels also add value to your property — research suggests a premium of around £1,800 to £2,500 for an average system. The environmental benefits are significant too: a 4 kW system saves roughly 840 kg of CO2 per year, equivalent to planting about 40 trees annually. If you are considering solar panels, get at least three quotes from MCS-certified installers and use our Solar Panel ROI Calculator to model your specific scenario.