Solar Panels

Solar PV for UK Homes: The Full Guide to Panels, Inverters and Getting Paid for Export

Solar photovoltaic (PV) panels capture energy from the sun and turn it into electricity your home can use, cutting what you buy from a supplier and, in some setups, earning money for what you export¹. A typical installation on a UK house costs around £6,100 and saves between £530 and £650 a year on electricity bills for a home without electrical heating or an electric vehicle, which means the system usually pays for itself in 10 to 12 years¹. More than 1.5 million homes in the UK already have panels², and the Welsh Government puts the figure at more than 1.4 million and growing every year³.

This guide covers the whole of domestic solar in the UK: what a system is made of, what it costs and saves, how the panels, inverter and mounting fit together, and the rules on planning permission, building regulations, MCS certification and grid registration. It also explains how export payments work and why using your own solar electricity first matters more than selling the surplus.

The benefits of solar panels for your home

A solar PV system turns daylight into electricity at the roof, which does three things for a household: it powers the home directly, it reduces bills, and it may earn money for electricity exported to the grid⁴. The scale of uptake shows how mainstream this has become. More than 1.5 million homes in the UK now have solar panels², and Energy Saving Trust reports nearly 1.7 million installations on homes across the UK⁵. The Welsh Government's own count is more than 1.4 million homes using solar power, a figure it says continues to grow every year³.

The bill saving depends on how much of the generated electricity the household uses itself, because rates for selling electricity to the grid are much lower than tariffs for buying it¹. That is why a typical home without electrical heating or an electric vehicle, which uses a moderate share of its own generation, saves between £530 and £650 a year¹. A home that shifts consumption into daylight hours, or adds a battery or a solar diverter, captures more of that value.

Solar is not total independence. The panels produce nothing after dark, so the household still draws from the grid overnight unless it has battery storage, and export income depends on a supplier offering a payment tariff. What solar does is reduce dependence on the grid and on imported electricity prices for the daylight part of every day, which in the UK is a large share of the year. For a fuller treatment of that trade-off, see solar panels and household energy independence.

From sunlight to electricity: how the components work together

The panels on the roof are only the first stage. When daylight strikes the photovoltaic cells, they produce a direct current (DC) of electricity, which then needs to pass through a solar inverter to turn it into alternating current (AC), the form your household appliances use¹. Energy Saving Trust makes the same point: an inverter is installed along with the system to convert DC electricity to AC⁵.

The inverter is the working heart of the system and the component most likely to need attention during the panels' life. Which? reports that inverters are not expected to last as long as the panels, and owners should expect to replace the inverter at some point during the life of the system⁶. The type of inverter also shapes how the system behaves: a string inverter handles the whole array as one, microinverters work panel by panel, and a hybrid inverter also manages a battery. Power optimisers sit at the panels and condition the output before it reaches a central inverter.

Once converted to AC, the electricity feeds the household circuits, and anything surplus flows out to the grid through the meter. The system must be registered with your Distribution Network Operator (DNO), the company that runs the local network, and your installer will usually register it for you⁵. That registration is what makes the installation official from the network's point of view and underpins export payments. The detailed rules are covered in connecting solar to the grid: G98 and G99.

Types of panel: monocrystalline, polycrystalline and thin-film explained

Solar PV panels sold for homes come in three broad technology families: crystalline cells, thin-film and hybrid⁷. Crystalline silicon panels are the familiar blue or black modules on most UK roofs, and they dominate the domestic market. Thin-film panels are made by depositing a photovoltaic material onto a substrate; common materials include amorphous silicon, cadmium telluride, and copper indium gallium selenide⁸. Hybrid panels combine approaches, layering technologies to capture more of the light spectrum.

For a householder, the practical differences show up in efficiency per square metre, appearance and cost, which is why the choice of panel matters more on a small roof than a large one. The cell-level technologies behind current panels, including PERC, TOPCon, n-type and heterojunction designs, are covered in solar cell technology, and the trade-offs between n-type and p-type cells are set out on their own page. Bifacial and glass-glass constructions, which change how a panel is built and how long it lasts, are covered in bifacial and glass-glass solar panels.

A separate technology that is often confused with PV is solar thermal, which uses the sun's energy to heat water rather than to generate electricity. Solar thermal panels are, according to nidirect, the most popular form of solar energy used in the UK⁹. The two can be complementary: a household can run PV for electricity and a solar water heating system for hot water, or use a diverter to send surplus PV into the hot water cylinder. The comparison is drawn out in solar thermal vs solar PV, and combined electricity-and-heat panels are covered under PVT panels.

Roof area needed for a typical 3.5 kWp array

The average solar panel system is around 3.5 kilowatt peak (kWp), a measure of the array's maximum output under standard test conditions¹. A 3.5 kWp system typically covers between 10 and 20 square metres of roof surface area and uses between six and 12 panels¹. The government's UK solar roadmap likewise refers to the cost of a typical 3.5 kW rooftop solar installation¹⁰. Which? gives a slightly larger average for the systems its readers buy: around 4 kWp, requiring at least 20 square metres of roof space¹¹.

The spread between the two size figures reflects what is being measured: one is the typical system installed on a UK house, the other an average across a consumer body's buyer survey, which skews to larger arrays. The number of panels for a given power depends on each panel's rating, so a system built from higher-output modules needs fewer of them and less roof.

Sizing is a balance, not a maximisation exercise. An oversized array on a roof the household cannot fill wastes money; an undersized one leaves bills higher than they need to be. The right size depends on daytime electricity use, roof area, budget and whether a battery is planned, all of which is worked through in what size solar system does a home need?. A surveyor will confirm the final panel count and layout before installation¹².

Where panels thrive and where they struggle

A mainly south-facing roof gives the best power output from solar panels, and southwest or southeast-facing roofs are also good². Roof pitch matters too: around 30 degrees is best², and the average UK home's roof slopes at 30 degrees, so most houses are already close to the ideal¹¹. A system facing east or west tends to get around 15 to 20 per cent less energy than one facing directly south¹, a penalty that is real but not disqualifying, and east-west arrays can suit households whose use is spread across the day, as discussed in are solar panels worth it on east or west roofs?.

Solar panels can be installed on both pitched and flat roofs. On a flat roof, the panels need to be tilted to maximise sunlight and spaced out so that one row does not shade the next¹. Shading is the other main performance factor: anything that casts a shadow across the array, from chimneys to neighbouring trees, cuts the output of the affected panels, and on a string system the effect can spread along the string. The mechanics of this, and the panel-level electronics that limit the damage, are covered in how does shade affect solar panel output?.

Roof condition is a practical gate rather than a performance one. The mounting system, whether on-roof rails or a roof-integrated design, attaches to the roof structure, so the covering and timbers need to be sound enough to take the load for the next 25 years, and building regulations and roof loading apply. A roof that needs re-covering soon is usually better done first. The full set of suitability factors, including mounting systems and ground-mounted solar where the roof is not an option, is covered in roof orientation, pitch and shading and which homes suit solar panels.

What you pay and what you save: £6,100 installed, £530 to £650 yearly

A typical solar panel installation costs around £6,100 for a system of around 3.5 kWp on a house¹. The same figure is given independently by NICEIC, which states a domestic solar panel system will set you back an average of £6,100⁸, by Energy Saving Trust, which says a typical solar system can cost around £6,100 to install⁵, and by Which?, which puts the typical cost at around £6,100 to install². Four separate bodies converging on one number is about as firm as a price figure gets in this market, though individual quotes vary with roof complexity, panel choice and inverter type.

Against that cost, a typical home without electrical heating or an electric vehicle saves between £530 and £650 a year on electricity bills¹. On those figures, solar panels usually pay for themselves in 10 to 12 years¹. The saving is not a fixed return: it depends on how much generated electricity the household uses itself, because export rates are much lower than import tariffs¹. Every kilowatt-hour used at home displaces a kilowatt-hour bought at the full retail rate.

At the small end, plug-in solar panels, the balcony-style kits that connect through a normal socket, are a different product class: suggestions are that costs could start around £400 for a basic setup, estimated from products available in the UK and Europe¹³. A full rooftop system in the same comparison is put at £7,400¹³, a higher figure than the £6,100 typical cost, reflecting the range of systems surveyed. The plug-in option is examined in plug-in solar kits in the UK and plug-in solar vs professionally installed solar. Full cost breakdowns, including what drives quotes up and down, are in how much do solar panels cost in the UK?, and the saving and payback mechanics are in solar panel savings and payback periods.

Self-consumption beats export payments

The economics of export are simple and unforgiving: rates for selling electricity to the grid are much lower than tariffs for using electricity from the grid, so using solar electricity yourself is much more cost-effective¹. A kilowatt-hour consumed at home avoids a retail-price purchase; a kilowatt-hour exported earns only the export rate. This single asymmetry explains most of the advice around running a solar home: shift washing, dishwashing and charging into daylight, and treat export as a bonus rather than the business case.

Export payments in the UK run through the Smart Export Guarantee (SEG), under which electricity suppliers pay for exported electricity, and eligibility commonly requires the installation to be certified, which is one reason households are told to check that the solar PV company is MCS certified or Flexi-Orb certified, as this is often required for government support schemes or to get SEG payments¹¹. The older Feed-in Tariff closed to new applicants, and households on it face a separate set of choices, covered in can I switch from FiT to a SEG tariff?. The payment side is set out in full in getting paid for solar export: SEG and the closed Feed-in Tariff.

There are two main ways to raise self-consumption beyond changing habits. One is adding battery storage, which moves midday surplus into the evening. The other is a solar diverter, which sends surplus electricity to the immersion heater in the hot water cylinder, converting cheap export into hot water the household would otherwise heat at retail rates; specific units such as the Solar iBoost+ and the myenergi eddi are covered on their own pages. Whether a battery is needed at all is a genuine question for many homes, addressed in can I get solar panels without a battery?.

When you need permission for installation

In most cases, placing solar panels on the roof of a house or flat, or on a building within the grounds, is considered permitted development under The Town and Country Planning (General Permitted Development) (England) Order 2015, Schedule 2, Part 14¹⁴. Cornwall Council states the position plainly: solar panels and equipment installed on domestic buildings and land are usually considered permitted development, meaning planning permission is not required, but there are a few exceptions¹⁵. The rights are commonly described as Class A and Class B permitted development rights for solar panels on domestic premises¹⁶.

The exceptions are where care is needed:

• Listed buildings. Panels must not be installed on a listed building under permitted development¹⁷, and solar panels on listed buildings need both planning permission and listed building consent¹⁶.
• Conservation areas and other designated areas. If you live in a listed building, a conservation area or World Heritage Site, or other designated area, you may need planning permission². Placing panels on a roof remains in most cases permitted development whether in a conservation area or otherwise¹⁸, but the limits differ.
• Walls facing a public road. In conservation areas, planning permission is required if panels are fitted to a wall facing a public road, defined in planning terms as a "highway", which includes adopted roads but not footpaths¹⁹.
• Non-domestic buildings. For industrial buildings and warehouses, permission is required if the installation is used for a purpose other than that of the undertaking, if it is within 5 metres of the curtilage boundary, or if the external appearance of the building is materially affected²⁰.

Where there is doubt, a household can apply for a Lawful Development Certificate, which proves an existing or proposed solar installation does not require planning permission and complies with the permitted development limitations and conditions¹⁷. The permitted development regime also has different limits on projections and on installations in protected areas²¹. Rules differ between the nations, so the detail is on separate pages for England, Scotland, Wales and Northern Ireland, with specific treatment of conservation areas and listed buildings.

Separately from planning, installing solar panels may also require approval under the Building Regulations⁴, and the Planning Portal advises contacting an installer who can provide the necessary advice, preferably one who belongs to the Competent Person Scheme²². Generally, installers that are MCS certified do not need to submit a Building Regulations application, though all installers should check with local Building Control²³. The technical side, including structural roof loading, is covered in building regulations and roof loading for solar panels.

The installer and product quality standard explained

MCS, the Microgeneration Certification Scheme, is a certification scheme for microgeneration installation companies and products, aiming to ensure consistent standards and provide confidence to consumers²⁴. It certifies, quality assures and provides consumer protection for microgeneration installations and installers, covering small-scale renewable electricity technologies such as solar photovoltaic panels, biomass, wind, heat pumps and heat products²⁵. The government describes it as "a mark of quality which demonstrates adherence to industry-recognised standards for renewable products, contractors and their installations"²⁶.

Certification is not issued by MCS directly but through certification bodies. Under one published scheme specification, installers must carry a current and valid MCS certificate issued by Certsure LLP t/a NICEIC, Napit Certification Ltd, Simply Certification, The IAA (Installation Assurance Authority), or Amtivo Group t/a British Assessment Bureau²³. The same document sets the installation standard: solar PV systems should only be installed and certified by MCS certified contractors working to the latest published MIS3002 standards, and the company providing the installation must carry a valid Trustmark and be MCS certified²³.

For a householder, MCS certification matters for three practical reasons. First, it is often required for government support schemes or to get Smart Export Guarantee payments¹¹. Second, certified installers generally do not need to submit a Building Regulations application, which simplifies the compliance side of a project²³. Third, it gives a route for complaint and redress: MCS is the contact point for issues with the installation process, the installer, or the MCS certificate or product²⁴. The scheme's scope, limits and complaint process are covered in MCS certification for solar PV installations, and the product testing standards behind certified panels are in solar panel standards and testing.

Finding and vetting a good installer

The first check is certification: check that the solar PV company is MCS certified or Flexi-Orb certified, as this is often required for government support schemes or to get SEG payments¹¹. The Planning Portal adds that it is advisable to contact an installer who can provide the necessary advice, preferably one who belongs to the Competent Person Scheme²². Beyond certification, Bromley Council's advice is simply to get various quotes to compare prices of different installers⁴, which is the single most reliable protection against an inflated quote.

A number of councils run Solar Together, a group-buying scheme that negotiates a price with a vetted contractor. Once you accept your offer, a surveyor will visit your property to assess whether your roof is suitable for a solar installation and confirm the number of panels, their location and other details such as cabling locations and colour¹². That survey stage matters: the offer price is confirmed only after the roof has been seen, and the panel count and layout can change from the initial estimate.

What to expect from a good installer, and what the installation process involves from survey to handover, is set out in solar panel installation: the process from survey to handover. The group-buying route is examined in what is the Solar Together scheme?. Households considering self-installation should read can you install solar panels yourself in the UK?, and anyone offered panels for nothing should check are free solar panel offers genuine?.

Owning a system: lifespan, inverter swaps and paperwork

Solar panels can have warranties of up to 20 or 25 years, but inverters are not expected to last as long, and owners should expect to replace the inverter at some point during the life of the panels⁶. Reported panel lifespans run longer than the warranties: estimates of 25 years or more and of 30 years or more both appear in independent guidance, and the figures differ, so treat 25 to 30 years as the reported range rather than a single number. The warranty position, including what degradation warranties actually promise, is covered in solar panel warranties, degradation and lifespan, and the signs that replacement is due are in how do I know if my solar panels need replacing?.

After installation, the system must be registered with your Distribution Network Operator, and your installer will usually register it for you⁵. In UK Power Networks areas, you must register it with UK Power Networks, again usually done by the installer¹. It is worth confirming with the installer that registration has been completed, since it underpins export payments.

Two MCS contact points are worth knowing. MCS can be contacted through mcscertified.com or by calling 0333 103 8130²⁸. MCS may also contact you for a short, routine post-installation verification on behalf of Ofgem, either via email or phone on 0333 103 8198, and property owners should aim to respond within seven days²⁸. Responding matters: verification is part of how the certification system maintains confidence in installed systems.

One limit to understand before problems arise: MCS requires installers to provide a design-stage prediction of system efficiency, not to verify actual performance, and MCS does not require remediation of systems that are underperforming relative to their design³⁰. The prediction is a modelling exercise, and the scheme's assurance sits with the installation process and the certificate, not with a guaranteed output. This makes the installer's own contract, guarantee and monitoring important, and it is why monitoring a solar PV system is worth setting up from day one. Routine upkeep is light: solar panel maintenance, cleaning and inspection covers what is needed and how often, and solar panels and home insurance covers the insurance position.

Solar panel makers available in Britain

The UK residential market carries a wide range of panel and inverter brands, and this site documents each of them in detail: on the panel side, ranges from AIKO Neostar, REC Alpha Pure, Jinko Tiger Neo, Trina Vertex S+, SunPower Maxeon, LONGi, Qcells, JA Solar, Sharp, SoliTek, GB-Sol and Solarwatt, among others; on the inverter side, Fronius, SMA, SolarEdge, Sungrow, Fox ESS, SolaX, Growatt, Sunsynk, Enphase, Hoymiles and GivEnergy-class hybrid units. Head-to-head comparisons, such as Enphase vs SolarEdge and Fronius vs SolarEdge, are on their own pages.

As an example of the accessory market around the core equipment, Enphase sells a Power Line Filter for single-phase installations in the UK, carrying a 2-year limited warranty³¹. At the time of writing the maker's own store lists it as out of stock, with a notify-me option when it is back in stock³¹. Accessories of this kind, filters, isolators and cabling, are part of a complete installation rather than headline products, and the electrical side is covered in solar DC cabling, MC4 connectors and isolators and solar PV safety: fire risk, DC isolation and surge protection.

Product availability moves quickly, and individual models are discontinued as ranges are updated, so a specification quoted today should be checked against the installer's current offer. The panel-level detail, including how to read a datasheet and what efficiency figures mean, is in reading a solar panel datasheet, and the technology families behind the brand names are in types of solar panel sold in the UK.

Solar power and cutting reliance on the grid

Solar PV is the most accessible form of household generation in the UK: it needs no fuel, no land beyond the roof you already own, and once installed it produces electricity every daylight hour at no marginal cost. The government has reported plug-in solar panels, an even lower-commitment entry point, becoming available in shops, with the stated aim of helping people save money on their bills³². At the other end of the scale, a full rooftop system with a battery can carry a household through most of its daily consumption without the grid, and off-grid solar is a genuine, if demanding, option for some homes.

The independence is real but partial, and the honest account states both sides. A grid-tied solar system does not run the house in a power cut, because standard inverters shut down when the grid goes down, a limit explained in do solar panels work in a power cut?. The household remains dependent on the DNO for its network connection and registration⁵, on a supplier for export payments¹¹, and on the inverter and panel manufacturers for hardware that will need replacement within the system's life⁶. Winter output is far below summer's, as covered in how much do solar panels and batteries produce in winter?.

What solar changes is the balance of that dependence. A household with panels buys less electricity, at prices it does not control, from companies it did not choose, and generates more of what it uses itself. Combined with a battery, a diverter and a shift of consumption into daylight, the typical £530 to £650 annual saving¹ can grow, and the household's exposure to price shocks shrinks. That is the case for solar as the foundation of household energy independence, and it is developed in solar panels and household energy independence.