Solar panel installation in Wales

Solar panel installation in Wales means fixing panels to a roof and wiring them to an inverter. The system then connects to your home and the grid. The technical standards match the rest of the UK, but Welsh planning and funding rules differ in places.

This page explains what the work involves, what shapes the price and what a good quote contains. Solar Cymru is an independent guide and enquiry service, and we do not install panels ourselves.

What a solar panel installation involves

The Energy Saving Trust describes a typical home system as about 4.5 kWp. That uses around 12 panels and covers roughly 20 to 30 square metres of roof. The installer starts with a survey of your roof, meter and consumer unit, and then designs the layout.

On installation day, the crew fixes brackets to the roof, mounts the panels and runs cables to the inverter. An electrician then connects the system to your consumer unit. Finally, the installer commissions the system and hands over your certificates and warranties.

Building Regulations normally apply to roof-mounted solar in Wales. Therefore the installer must check that your roof can carry the extra load, and some roofs need strengthening first. An installer in a competent person scheme can certify the work and notify the council for you.

What affects the price

Government data on 2025-26 installs points to about £1,400 to £1,950 per kilowatt across Great Britain, with Welsh figures inside that range. That figure excludes batteries. For a typical 4.5 kWp home it means roughly £6,500 to £8,800. The Energy Saving Trust average of £7,600 sits inside that range.

Several things move your quote up or down. For instance, the 2025-26 data shows a lower cost per kilowatt in the 4 to 10 kW band than in the 0 to 4 kW band. Slate and tiled roofs need careful bracket design under MCS rules, so they can add work. Power optimisers help only where shade falls on part of the array, so ask whether you need them.

VAT on home solar installations in Great Britain is 0% until 31 March 2027. It is due to rise to 5% on 1 April 2027 unless the law changes. A battery fitted at the same time gets the same rate as the panels.

Savings depend on how much power you use yourself. The Welsh Government says households with solar save over £500 a year on average. The UK Government gives an example of about £450. The Energy Saving Trust puts payback in mid Wales at around 9 to 10 years.

Our post on how much solar panels cost in Wales goes into more detail. Meanwhile, how many panels a home needs explains system sizing.

Roof direction also changes the return. Roofs facing east or west make about 15 to 20% less than a south-facing roof, yet they can still work well. Read our post on east-west and north-facing roofs before you rule one out. Our solar yield guide for Wales shows expected output across Welsh places.

Planning, grid and funding points

Panels on the roof of a house often count as permitted development, so you may not need planning permission. However, the panels must not stick out more than 200 mm from the roof slope. They must not stand higher than the highest part of the roof, not counting a chimney. Our planning permission guide for Wales covers the exceptions.

Grid rules depend on the inverter rating, not the panel size. Systems up to 16 amps per phase follow the G98 route, which means 3.68 kW on a single-phase supply. In that case the installer sends the paperwork to your network operator within 28 days of commissioning. Larger systems need the operator’s agreement before the work starts, so ask which route applies. Our grid and export guide explains the two Welsh network operators.

There is no dedicated UK Government grant for solar panels. In Wales, however, Warm Homes Nest can include solar in a free package for eligible low-income homes. Green Homes Wales also offers owner-occupiers interest-free loans of £1,000 to £25,000. Warm Homes: Local Grant is for England only, so it does not apply here. Read our solar funding guide for Wales before you assume any help is on offer.

What a good quote contains

A good quote names the exact panels, inverter and mounting system. It states the system size in kWp and shows how many panels fit your roof. It also includes the MCS performance estimate, which sets out orientation, inclination and a shade factor.

Because actual output can differ from the estimate, ask how the installer assessed your roof. Ask what the quote excludes, for example scaffolding or consumer unit upgrades. Check whether the installer has asked your roof warranty provider about the work.

Protection matters as much as price. Under the redeveloped MCS scheme, installers must buy financial protection that gives at least six years of cover. The scheme caps the claims excess at £250. Meanwhile, members of the Renewable Energy Consumer Code never ask for deposits above 25% of the cost. Our post on MCS certification and your quote explains what to check.

Finally, look at aftercare. Panels need little maintenance, but your installer should leave written maintenance and fault guidance. Our post on cleaning and maintaining panels shows what to expect in a wet climate. Our guide to choosing an installer lists the questions to ask.

How the Solar Cymru enquiry works

You complete a short enquiry form on our get quotes page. Solar Cymru passes your details to MCS-certified installers through the MoreLeadz lead system. An installer then replies to you about a survey and a written quote. The step is opt-in, so you decide whether to go ahead.

We are not an installer, lender, broker or government service. Therefore we cannot promise a price, a grant or a date. Compare at least two written quotes, and read each one against the checklist above.

Local detail can change your plans. For example, you can read about solar installers in Cardiff or solar panels for homes around Swansea. We also cover solar installation in Newport and solar panel quotes around Wrexham.