How to Buy Solar Panels
Solar PV Installation
By Beth Askham
Article 5 of 12
Solar PV Installation
We've filmed an installation of solar photovoltaic panels so you can see what to expect. Plus, find out whether your property is suitable for solar panels.
Considering buying solar panels? Watch our video to find out what happens when solar panels are installed, and learn whether your home's suitable for solar.
The picture, above, shows a Which? member's roof undergoing installation of a 3.5kWp solar PV system. Keep reading to find out all you need to know about solar panel installation and download our free solar PV installation checklist.
Make sure you buy good quality solar panels – see our solar panel reviews.
Installing solar panels
If the solar panels are to be installed on your roof, you're probably going to need scaffolding. Make sure you check with the surveyor that there is space to install scaffolding and that the quote includes the cost of it.
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 – this is why a proper surveyor should go into your loft to check the integrity of the roof and the rafters. The solar panels will then be clamped on to the fixing brackets.
Video guide: solar PV installation
To get a better idea of what you can expect when installing solar PV, 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.
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 aren't thinking of moving home in the near future.
Although a south-facing roof would yield the best power output, a southwest or southeast-facing roof should also be fine, but you would get less power out of the system.
How much energy you could produce with solar panels – and therefore how much money you could make – will depend on:
- the tilt angle of your roof and its orientation
- where you live: the South West gets more sun than the North, for instance, and this could affect the amount of electricity your system will generate, although not too significantly.
Can you make money from solar panels? Find out if solar PV is a good investment.
What is the best roof orientation 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 (south, west, 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 roofs that face north.
You also need to consider both the age of your roof and how strong it is, as PV panels are heavy.
Solar PV systems are most efficient if you use the electricity they produce during the day. So if you work all day, leaving your home empty, you may not reap the full benefits of your solar panels.
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. Do consider whether nearby trees are likely to grow and overshadow your roof.
We've spoken to solar panel experts and solar panel owners to get their top tips on to make the most of your solar panels.
What size of solar PV system is right for my home?
The right size for your home will mainly depend on the roof space available and how much electricity you use. We recommend that you don't buy too large a system, as you cannot meet 100% of your demand with solar PV.
Make sure the surveyor understands your electricity usage so you get the right-sized system for your needs and budget. As a guide, an average 4kWp system would cost between £5,000 and £8,000.
Before you install solar PV, read our tips and advice on what you should do and the questions you need to ask a solar PV installer. See our free downloadable and printable solar PV installation checklist.
Do I need planning permission for solar PV?
Contact your council to see whether you need to apply for planning permission for your solar panels. You won’t need planning permission for most domestic solar panels, as long as they respect certain size criteria.
However, exceptions apply for listed buildings, buildings in conservation areas and World Heritage Sites.
Do solar panels need cleaning?
Solar PV panels are self-cleaning when installed on an ideal roof slope, so should either never or only rarely need cleaning. But if your roof has a fairly shallow pitch or is flat, it may accumulate bird droppings, leaves or dirt, which will leave them needing occasional cleaning.
Are there any other maintenance or ongoing costs to consider?
Solar panels are pretty much maintenance-free and should last for at least 25 years.
Solar PV systems are relatively simple and have no moving parts, so they don't need much looking after. However, within 25 years, you’ll need to replace the inverter, which costs about £1,000 (be wary – some installers say it costs less).
What’s the best way of finding a reputable installation company?
Request a site visit with a technical survey, not a sales visit, and get at least three quotes. Ask for recommendations and addresses of installations in your local area that you could go and see. You can use Which? Trusted Trader to find trustworthy local solar panel installers recommended by other solar panel customers.
In order to take part in the Feed-in Tariff (Fit) scheme and earn money for generating renewable energy, your installer needs to be Microgeneration Certification Scheme-certified. You can check this on the MCS website.
How can I ensure the installation process 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 30-40cm between the last panel and the roof edge to allow for access and to minimise the risk of wind blowing the panels off.
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, use the Which? solar installation checklist.