The average UK home solar panel installation costs around £6,100 for a 4.5kWp system, according to the Energy Saving Trust's July 2026 figures. That price includes panels, inverter, mounting hardware, and labour. At current electricity prices and with Smart Export Guarantee (SEG) export income, payback runs roughly 9 to 12 years depending on where you are in the country and how much electricity you use during the day.
This page breaks down what drives the price, what the 0% VAT deal actually covers, how SEG works, and what government support exists (spoiler: there is no universal UK solar grant, but there are targeted schemes worth knowing about).
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Get My Free Quotes →What does a solar panel system cost in the UK?
The Energy Saving Trust, which publishes cost benchmarks verified against industry installer data, puts the typical system at 4.5kWp costing around £6,100 (figures updated 1 July 2026). That covers a roof installation for an average three- or four-bedroom house with decent south-facing roof space.
System size is the biggest cost driver. Larger systems cost more to buy but generate more electricity, so the right size depends on your roof space, your daytime usage pattern, and your budget. The table below gives a rough sense of the cost range.
| System size | Typical cost range | Approx. annual output (UK average) | Suited to |
|---|---|---|---|
| 3kWp | £4,500 – £5,500 | 2,400 – 2,700 kWh | Smaller homes, limited roof space |
| 4kWp | £5,500 – £7,000 | 3,200 – 3,600 kWh | Average 3-bed house |
| 4.5kWp (typical) | ~£6,100 | 3,600 – 4,050 kWh | 3–4 bed house, average usage |
| 5kWp | £7,000 – £8,500 | 4,000 – 4,500 kWh | 4-bed house or higher usage |
| 6kWp | £8,500 – £10,500 | 4,800 – 5,400 kWh | Large homes, EV charging, heat pumps |
Output estimates use the MCS methodology range of roughly 800 to 900+ kWh per kWp per year for a south-facing UK roof, with the higher end reflecting southern England and the lower end reflecting northern Scotland. Actual output depends on orientation, pitch, shading and location. Source: MCS MIS 3002 standard; cost benchmarks from the Energy Saving Trust (July 2026).
Does the 0% VAT apply to solar panels?
Yes: supply-and-install of solar panels currently attracts 0% VAT, not the standard 20%. This zero rate covers the installation of energy-saving materials, including solar PV panels, inverters, and battery storage, in residential accommodation. It is confirmed to run until 31 March 2027, after which it reverts to the 5% reduced rate (not 20% as some older content states). Source: gov.uk VAT Notice 708/6.
If you are getting quotes before 31 March 2027, the price you receive should already show 0% VAT. From 1 April 2027, expect quotes to include 5% VAT on the supply-and-install element. Supply-only purchases (buying panels without a certified installation) may be treated differently. Check with your installer if you are in any doubt about what VAT rate applies to your quote.
What drives the price of a solar installation?
Beyond system size, a few factors push quotes up or down.
Roof type and complexity. A straightforward pitched roof with south-facing aspect and no shading is the cheapest install. Flat roofs need ballasted mounting frames. East-west split systems on a hipped roof involve more labour and two inverter strings. Listed buildings or conservation areas may need planning permission, which adds time and cost.
Panel quality and inverter choice. Budget panels and string inverters are cheaper upfront. Higher-efficiency panels from manufacturers with longer power warranties generate slightly more electricity per square metre, which matters if your roof space is limited. Microinverters or power optimisers add cost but reduce the impact of partial shading.
Battery storage. Adding a battery roughly doubles the upfront cost relative to panels alone. The Energy Saving Trust puts battery storage at an additional £5,000 to £8,000 on top of the panels. The 0% VAT zero rate also covers battery storage installed alongside or retrofitted to a solar system until 31 March 2027. Whether a battery makes sense financially depends on how much surplus power you currently export versus how much you buy back in the evenings.
Location and scaffolding. Urban areas with good installer competition tend to see keener pricing. Very rural locations may add a travel or call-out cost. Multi-storey homes with complex access can push scaffold costs up.
G98 versus G99 connection. Most domestic systems are designed to stay within 3.68kW per phase, which means the installer can commission first and notify the Distribution Network Operator (DNO) within 28 days (the EREC G98 process). Systems above 3.68kW per phase need prior DNO approval before connecting (EREC G99), which can add weeks to the project. Your installer handles this paperwork. Source: Energy Networks Association.
The Smart Export Guarantee: what you earn for power you don't use
The Smart Export Guarantee (SEG) pays you for every unit of solar electricity you export to the grid. It replaced the old Feed-in Tariff (FiT) for new applicants. The FiT closed to new applicants in March 2019 and is no longer available to new solar installations. The SEG launched on 1 January 2020.
SEG rates are set by each supplier, not the government. Larger suppliers (those with 150,000 or more domestic electricity customers) are legally required to offer a SEG tariff; smaller suppliers do so voluntarily. Rates must be above zero but are otherwise market-determined, so they vary and move frequently. Based on Ofgem's SEG framework, here are two current examples (verified July 2026):
- Octopus Energy (Outgoing Octopus): 12p/kWh flat rate; or a time-of-use variant paying 16p/kWh between 4pm and 7pm and 9p/kWh at other times. Smart meter required.
- British Gas: 12p/kWh for own electricity customers with systems up to 15kW; lower rates for non-customers and larger systems.
Most homes export roughly a third to half of what their panels generate, depending on daytime usage. The Energy Saving Trust's current figures use 12p/kWh as a typical SEG rate for payback calculations, a reasonable working figure, though your actual tariff may be higher or lower. Do not use the FiT rate from an old quote or a neighbour's existing system as your benchmark.
To register for SEG, your installer needs to be MCS-certified and your system needs an MCS certificate. Most suppliers will ask for this certificate when you apply for a tariff. You don't legally need MCS certification to have panels installed, but without it you won't qualify for SEG or any grant scheme, so in practice always use an MCS-certified installer (check the register at mcscertified.com).
Payback period: how long before solar pays for itself?
At current electricity prices and with SEG export income, the Energy Saving Trust calculates payback at roughly 9 to 12 years for a typical UK installation (July 2026 figures). That is across five locations: London at around 9 years, Manchester at 10 to 11 years, and Stirling at 11 to 12 years, reflecting the yield difference between the south of England and Scotland.
The single biggest driver of payback speed is self-consumption (the proportion of solar output you use directly rather than exporting). Electricity you consume yourself displaces grid electricity at the full unit rate; electricity you export earns the SEG rate. At current grid prices, consuming solar directly is worth more than exporting it. Households that run dishwashers, washing machines, and other high-load appliances during daylight hours see faster payback than those who are out all day.
A battery can improve self-consumption by storing surplus daytime generation for use in the evening, but at current battery prices the payback on a system with battery tends to be longer than on a panel-only system, all else being equal. Whether the combined system makes sense financially depends on your usage profile and how long you plan to stay in the home.
Is there a grant for solar panels in the UK?
There is no universal UK grant that pays every homeowner toward a solar installation. This is the single most common piece of wrong information circulating about UK solar. The situation is more targeted:
Warm Homes Plan. Launched in January 2026, the government's ~£15 billion Warm Homes Plan includes fully funded solar panel installations for low-income households. Delivery is rolling out, and eligibility and application routes are still being confirmed by delivery bodies. The Energy Saving Trust describes it as covering "solar panels, batteries, heat pumps and insulation" for eligible low-income homes, with low and zero-interest loans available for other homeowners. Source: gov.uk Warm Homes Plan.
ECO4. The Energy Company Obligation scheme (ECO4) provides funding for insulation and heating measures for fuel-poor and low-income households. It runs until 31 December 2026 and is administered through energy suppliers. Solar PV is within scope for ECO4 in some cases. Source: ofgem.gov.uk.
Great British Insulation Scheme (GBIS). This scheme ended on 31 March 2026. It is no longer accepting new applications.
Home Energy Scotland. If you own a home in Scotland, the Home Energy Scotland grant and loan scheme provides heat pump and insulation funding, but it does not currently offer a grant for standalone solar PV. Solar PV-T hybrid systems can access a loan. Heat pump funding is separate and substantial (up to £7,500 grant plus a £7,500 optional interest-free loan). Source: homeenergyscotland.org.
For most people (those who do not qualify for low-income or benefit-linked schemes) the primary financial support for solar right now is the 0% VAT rate until March 2027 and the ongoing Smart Export Guarantee income. Both are real and worth factoring in; just don't plan your budget around a grant that doesn't exist for your situation.
Permitted development: do you need planning permission?
In England, rooftop solar usually falls under permitted development, so you do not need to apply for planning permission, provided the installation meets the conditions set out on planningportal.co.uk. Key limits: panels on a pitched roof must not project more than 200mm from the roof slope or exceed the highest point of the roof (excluding chimney). On a flat roof the equipment cannot sit more than 600mm above the highest part of the roof. You cannot install under permitted development in the grounds of a listed building or on a scheduled monument, and in a conservation area panels must not face a highway.
Rules differ by nation. Scotland, Wales and Northern Ireland each have their own permitted development regimes. Do not assume England's rules apply elsewhere. Check the relevant national planning authority if your home is in Scotland, Wales or Northern Ireland.
If your home is a leasehold flat, you will likely need the freeholder's permission regardless of permitted development rules.
This page covers the headline costs and payback. Our other guides go deeper on specific topics.
How to compare solar quotes
When you receive installer quotes, a few things are worth checking beyond the headline price.
Is the installer MCS-certified? Verify at mcscertified.com before signing anything. MCS certification is what qualifies your installation for SEG payments and any applicable grant scheme. Also check they hold RECC or HIES consumer-code membership, which gives you access to an independent dispute resolution service if something goes wrong.
Are the quotes on the same system size? A quote for a 3.5kWp system is not comparable to one for a 5kWp system. Ask each installer to quote on the same kWp size, or ask them to justify why they've sized the system differently.
What does the warranty cover? Panels typically carry a 25-year power output warranty. Inverters typically carry 10 to 12 years, sometimes extendable. Check what the installer's workmanship warranty covers and for how long.
Is scaffolding included? Some quotes exclude scaffold costs. Clarify upfront so you are comparing like for like.
What is the projected SEG income based on? Be cautious of quotes using very high export rate assumptions. A 12p/kWh flat rate is a reasonable working figure at current market rates; if a quote projects 20p+ throughout a 25-year analysis, ask where that figure comes from.