Solar panel installation

Considering buying solar panels? Find out first if your home is suitable, then learn more about what to expect when installing solar panels.

Getting solar panels installed isn't as disruptive as you might think. When we surveyed solar panel owners in April 2024, many said the process was relatively easy. In fact 80% of them told us they would install solar panels again if they moved home.*

Before installing solar panels you'll need to check whether your home is suitable, and you also may need planning permission.

See what owners think of their solar PV systems in our our solar panel reviews.

Video guide: solar PV installation

Watch our video below to see a solar panel installation (on a concrete tiled roof) from start to finish, and find out what's involved.

How long does it take to install solar panels?

If the solar panels are being installed on your roof, you're probably going to need scaffolding. 

Once the scaffolding is up, the panels could be installed in less than a day. Roofers will attach the fixing brackets on to the rafters of your roof – for this reason, a qualified surveyor should go into your loft to check the integrity of the roof and the rafters first. The solar panels will then be clamped on to the fixing brackets.

The size and complexity of your system will affect how long installation takes. Ask your installer for an estimate of timings so you're prepared.

If scaffolding is needed, check with the surveyor that there is space for it and that the cost is included in your quote.

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Do I need planning permission for solar panels?

Before you spend time and money on getting surveys or quotes, you need to know whether there's anything stopping you from installing solar panels.  

Generally, you won’t need planning permission for most domestic solar panel installations, as long as they're fitted within certain limits. 

Roof-mounted panels – on your home or on an outbuilding situated within the boundary of your property – benefit from what are known as 'permitted development rights' and won't need permission so long as they are fitted to minimise the effect on the external appearance of the building. 

In practice, this means that: 

• On a pitched roof, panels should not be installed above the highest part of the roof (excluding the chimney) and should project no more than 200mm from the roof slope or wall surface.
• On a flat roof, the highest part of the solar PV equipment should not be more than 600mm higher than the highest part of the roof (excluding chimney).

In some cases, however, permitted development rights are more limited. If your home is in a designated area, such as a National Park, an Area of Outstanding Natural Beauty, the Norfolk or Suffolk Broads, a conservation area or World Heritage Site, you may need to apply for planning permission.

There are also different requirements for listed buildings, or a building that is within the grounds of a listed building or on a site designated as a scheduled monument. If your property is in a conservation area, or in a World Heritage Site, panels can't be fitted to a wall that faces onto the road.

Standalone solar arrays – not fixed to a building but within the boundary of your property – can also qualify as permitted development, but they are subject to greater restrictions. 

For more information, contact your local planning authority – your local council – for advice about planning permission for solar panels.

If you are a leaseholder, you'll also need the permission of the freeholder to install solar panels.

Is my home suitable for solar PV panels?

Solar PV panels are worth considering if you have a mainly south-facing roof with little or no shade and you're not thinking of moving home in the near future.

How much energy you could produce with solar panels – and therefore how much money you could make or save – will depend on:

• the size of your roof (the area you have available for panels)
• the pitch of your roof (the angle at which it tilts)
• the orientation of your roof (whether it faces north, south, east or west)
• the location of your home (which will affect how many hours of sunlight your home gets)

Each of these factors affects the amount of electricity your system will generate. Individually, each one is not too significant, but if your home is less than optimal on every count, then solar panels may not be a good investment for you. 

For example, a south-facing roof will give the best power output, but a south-west or south-east-facing roof is also good. You will get slightly less power out of the system, and therefore save less on your electricity bill but, as long as other factors are favourable, you can still get a good result.

And although the south-west of the UK gets more sun than northern locations, solar panels can still be a good choice in many parts of the country, assuming other factors are in your favour.

The size of the solar installation is a big factor affecting electricity generation. Although it will cost more upfront to install more panels, a larger solar panel system will always generate more electricity. However, if you generate more than you can use during the day, you'll need a storage battery to make the most of it. Learn more about this in our guide on solar panel battery storage.

Use our solar panel buying advice and see our solar panel brand reviews to help make your decision.

What is the best angle and roof direction for solar panels?

The table below shows the percentage of the maximum output you will get from a solar PV system, depending on your roof orientation (west, south, east) and tilt angle (source: the Energy Saving Trust). 

Most UK roofs are angled at between 30 degrees and 45 degrees. Solar PV panels are not recommended for a roof that faces north.

You also need to consider both the age of your roof and how strong it is, as PV panels are heavy. 

Shade could be a big problem for solar panels, so no panels should be installed where there is shade from trees, chimneys, walls or other obstructions. 

A small amount of shading at the beginning or end of the day won't significantly affect the output of your panels, but consider whether nearby trees are likely to grow and overshadow your roof in future.

See our top tips to make the most of your solar panels.

Solar panel maintenance costs

Solar panels are pretty much maintenance-free and should last for at least 25 years. 

Most panels are self-cleaning – their special coating allows rainwater to wash away dirt and debris – but you may need to clean them if they are affected by bird droppings, or sticky sap from trees, for example.

Solar PV systems are relatively simple and have no moving parts, so they don't need much maintenance. 

Nearly half of owners hadn't done any maintenance on their solar panels since they were installed, when we asked solar panel owners.*

The most popular maintenance job (done by a quarter of respondents) was a visual inspection to check for dirt, debris or damage.

However, within 25 years, you’ll need to replace the inverter – 15% of owners had a problem with their inverter in our survey.

Once you’ve had solar panels installed, your installer should give you written details of any maintenance checks you need to carry out occasionally to check your system is working properly.

Use our Trusted Traders search tool to find a solar panel installer in your area. 

Some energy providers also install solar panels, and might offer alternative financing options. You can find out more about getting solar panels through an energy supplier.

How can I ensure my solar panel installation goes well?

Make sure you don't end up with panels overhanging the roof. Where panels are fitted just above the existing roof, it's good practice to leave at least 40cm between the last panel and the roof edge. This minimises the risk of strong wind blowing the panels off and nuisance wind noise, and the panels affecting ridge tiles, rainwater run-off and snow build-up. 

So before your installer draws up the plans, ask how much space they're leaving between the panel and the roof's edge. To ensure you get a thorough survey, follow our tips:

Before the visit:

• Check local planning regulations to make sure you're allowed to install a solar PV system (see above).
• Check that the solar PV company is MCS certified and a member of the Renewable Energy Consumer Code (RECC). 
• Don't accept a price over the phone before the firm has visited. 
• Get an Energy Performance Certificate for your home. 
• Find your energy use for the last year. Here's how to estimate your energy use.
• Check with your home insurer that they will still insure you with solar panels.

During the visit:

• Check if the company representative is a salesperson or surveyor. Only a surveyor can give an accurate quote, after doing a survey. Don't sign a contract based only on a salesperson's visit.
• A good surveyor should do a technical site survey including looking at roof orientation, measuring roof tilt, assessing roof quality (inside and out), record any risks of shade on the panels (taking into account how this will change over time and at different times of the day and year), looking at your fuse box and metering, asking about your electricity use (and when you use it), discussing where to locate cables and equipment.

After the visit:

• You should get an in-depth quote from the company, including information on the PV panels, inverter, warranties, terms and conditions, and how it has calculated the payback, rate of return and savings.
• Ask for a breakdown of the quote and check it includes full costs of the installation (e.g. scaffolding) and any applicable VAT.
• Check whether the quote is tailored to your property and energy use (rather than being based on averages).
• Did they use SAP (the government-recommended method) to estimate performance, or their own method?
• Check that the system comes with a guarantee.
• Ask who will be doing the installation. Is it is the same company or a sub-contractor?
• What maintenance would the panels need? Is this included within a package or would you need to pay separately?

The company should not do anything to pressure you into buying the system that day. They shouldn't offer large time-limited discounts to tempt you, or use other pressure-selling techniques. 

Our research

*In April 2024 we conducted an online survey of 2,039 Which? Connect members with solar panels on their home.