Our guide to solar panels for the home – the costs, installation and grants available for domestic kits

The popularity of solar panels has increased dramatically since 2020, but are they worth it?

You’ve probably spotted an increasing number of solar panels popping up on roofs all around the UK. And it seems this trend is only set to continue.

Due to the pandemic, large numbers of us are now spending a lot more time at home during the day. So investing in solar panels could be hugely beneficial for our energy bills at the end of the month. And that’s without even mentioning the positive effects that reducing our reliance on fossil fuels will have on our planet.

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According to a 2020 government report, over 970,000 UK homes have solar panels, and numbers are increasing rapidly. 'We’ve increased staffing by 50 per cent since the start of lockdown to keep up with demand,' says Tony Sampson, managing director at Naked Solar. (opens in new tab) 'And we’re still growing.'

Intrigued? You should be. The cost of solar panel technology has dropped massively over the years (around 25 per cent since 2014). So, if you were thinking of making the investment, now is a great time.

What types of solar panels are available?

There are two main types of solar panels: solar thermal for your hot water, and photovoltaics, also known as solar PV, for your electrics.

There are, naturally, differences between the two. So it pays to know what you’re after and what will suit you and your home best.

Photovoltaic panels

exterior of house with photovoltaic panels and wooden gate

(Image credit: Exeo Energy)

Are made of a polycrystalline material containing silicon cells and strips of wiring, known as ‘buzz bars’, framed in metal and cased in glass. They convert light into energy while the sun is shining. So it’s a good idea to get your washing done, run the dishwasher and carry out any other high-powered tasks then.

These are best placed on a south-facing roof so they absorb as much light as possible during the day.

Solar thermal panels

solar thermal panels on pitched roof

(Image credit: Gregor Heating)

The key difference between solar thermal and photovoltaic panels is that solar thermal works on UV rays, rather than sunlight itself. This means they still work effectively in diffused, or lower levels, of sunlight.

'This means that even on a light cloudy day, you’ll still generate a decent amount of energy from your panels,' says Richard Blackmore, renewable technical support at Gregor Heating (opens in new tab).

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How do solar panels work?

The way your solar panels will work varies slightly depending on what type you have.

How Photovoltaic panels work

'The cells in the panels have been dyed the right colour to ensure that the correct spectrum of light is enabled and reacts accordingly when the light hits them,' says Ben Robinson, director at Exeo Energy (opens in new tab).

'This creates electrons that pass between the two sides of the cell generating the current. This is fed along the buzz bars and into an inverter box that converts it into power. You then connect all your solar panels together, so you get a large-scale version that increases the voltage.'

At night, or in winter, where the sun isn’t strong enough to generate solar power, your home will automatically revert to using the national grid. Likewise, any solar energy not used during the day will also be fed back to the grid. You’ll be paid for this excess via the Smart Export Guarantee scheme (more on this below).

If you’d prefer to keep your solar energy for your own use, rather than send it back to the grid, there are battery systems available that keep it stored for when the sun isn’t strong enough for generation. 'The electricity gained from this should power the average house for one or even two days,' adds Tony at Naked Solar.

While there are various technologies that give the panels different aesthetics, all-black panels see the highest demand for residential homes as these tend to blend with roofs best. Even better, you can now get sunken panels that lie flush with the roof, which are even more unobtrusive. 'If you’re working on, or replacing, your roof, this is a good time to install these,' says Ben.

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How solar thermal panels work

The setup for most domestic houses will consist of two panels on the roof, with a pair of pipes that run to a solar pumping system in the roof, and another pair running down to the hot water cylinder.

According to Richard, this setup should provide the bulk of your hot water from March through to September and October. 'During the winter the system will then act as a pre-heater, taking your water temperature up to about 30/35 degrees, until your boiler tops it up to the required temperature,' he continues.

The setup is completely separate from your existing hot water system, but it does work in conjunction with it. So, if you’re looking to upgrade your current property, rather than starting from scratch on a new build, you’ll need to change your cylinder from a standard to a twin coil model to accommodate the new hot water source.

As a bonus, most solar thermal systems only use two 2m x 1m panels, in comparison to the run of 10 to 12 that is needed for photovoltaics. Like with solar PV, they can be roof-mounted or there are in-roof options, too.

How much do solar panels cost?

heating rural cottage with solar panel

(Image credit: Gregor Heating)

For the average British home, budget £6,000 to 7,000 for the installation of Photovoltaic solar panels.

There are no longer any grants available to help offset these initial costs – as we'll explain later. But, saying that, there are ways to be savvy and save on these costs.

'The price of solar panels themselves has come down dramatically,' says Ben. 'A large proportion of the cost of an installation is often tied up in the scaffolding.'

'You need edge to edge protection for your roof so it can be quite a chunk of the overall budget. That means that, if you need to carry out any other roof work, or to paint the front of your property, it can be much more cost-effective to install your solar panels at the same time.'

Solar thermal panels cost slightly less. 'You should look to budget around £5,500 for a typical two-panel solar thermal system, plus VAT,' advises Richard. 'The VAT element is only five per cent, though, as long as there’s no additional panels, so that’s positive.'

Unlike solar PV, where there are no grants available, owners of solar thermal panels can benefit from recouped costs via the Renewable Heat Incentive, see below.

How are solar panels installed?

How to install solar thermal panels

  1. Survey the roof properly to determine the correct products to use for your home’s covering.
  2. Mount the panels on the roof. For a two panel system, you’d use eight brackets. These simply hook over your home’s tiles.
  3. The only incision made in the roof is in the felting for the pipes that run to the solar pumping station. This is then carefully covered over to prevent water ingress.
  4. Then it’s time to hook the panels onto the brackets. Solar thermal panels are a lot heavier than solar PV. Depending on the results of the initial assessment, you may need a structural survey carried out to ensure the roof can handle the weight of the panels.
  5. Once the panels are on and the pipes are popping through the roof, it’s time to mount the solar pumping station in the loft. Be sure to use the correct pipes due to the heat of the water generated from the solar – sometimes it can reach over 100 degrees.
  6. Wire in the pumping system and install the twin coil cylinder, connect the heating system up – and you’re done!

exeo energy panel solar panels installed on pitched roof

(Image credit: Exeo Energy)

How to install Photovoltaic panels

  1. This process should take three days, from start to finish. First, your supplier will assess the roof type, structure and covering, to determine the correct products that can be used based on your needs. This can even be done remotely via looking at Google Earth (opens in new tab).
  2. Next, it’s time to install the scaffolding and make sure that the roof is safe to work on
  3. Then it’s time for installers to put up the framing and solar panels.
  4. Finally, electricians will connect up the panels and install the inverter, meter and switch gear and plug it into the home’s fuse board. Then you’re done!

What solar panel grants are available in the UK?

solar panels on on blue timber clad burn conversion

(Image credit: Polly Eltes/Future PLC)

There is money available for those using solar thermal panels to heat their home via the Government’s Renewable Heat Incentive (opens in new tab) (RHI). If you join the scheme (and, importantly, stick to the rules) you can receive quarterly payments over seven years. The amount will vary based on the amount of renewable heat generated by your home.

Properties in England, Scotland and Wales are allowed to apply. You must be a landlord or own your own home. New builds are typically ineligible, unless you’re undertaking a self build.

'The way they judge your performance is based on your property’s energy performance certificate,' says Richard. 'Whatever your annual hot water performance is expected to be – whatever that figure is, multiply it by 23.36 pence, the current rate, that will tell you what your income will be.'

Unfortunately, if you’re looking to install Photovoltaic solar panels for your electrics on your roof, there are no longer any government grants to help you shoulder the costs of installation. So the only savings you’ll be making are those on your electricity bill once the panels are up and running.

Saying that, on 1 January 2020, the government set up the Smart Export Guarantee (SEG) scheme, to replace the now-defunct Feed-In Tariff. The SEG requires energy companies with at least 150,000 customers to pay households for any solar-generated electricity they send back to the National Grid.

The rate you get back will depend on the supplier, though, as all the government requires is that it’s a payment ‘higher than zero.’ Still, it’s something – and can help to offset the costs of installation in the long run.

Are solar panels worth it?

solar panel on house extension with green framed windows

(Image credit: Future PLC/Polly Eltes)

Essentially, yes, solar panels are worth it. Both kinds of solar panel can help you make savings on your energy bills, while helping to chip away at the UK’s reliance on fossil fuels.

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'If you’ve got a large family, lots of bathrooms, and water usage is high, a solar thermal system is absolutely worthwhile. You might not use your boiler and, thus, any gas or oil, at all during the summer months,' says Richard. 'But if you’re in a one-bed flat where it’s not easy to install or there’s no roof access or you only have a very small tank, then it’s probably not for you. This system is aimed at properties where installation is easy.'

Really, it’s up to you to decide whether the savings you can make on your bills are worth the cost of installation. But Tony reiterates that demand for solar PV is growing. He adds that some customers have even wanted installs before moving. They believe the panels will increase the value of their home.

'There are clearly a lot of people that think solar panels are worth it,' Tony says. 'We can’t keep up with demand. Plus, new battery technology means it’s a lot less critical to use the energy your panels create during the day, as was the case in the past. Now it can be stored until you need it, which is much more efficient.'

Amy Cutmore
Amy Cutmore

Amy Cutmore is Editor-in-Chief, Homes Audience, working across the Future Homes portfolio. She works on titles including Ideal Home, Homes & Gardens, Livingetc, Real Homes, Gardeningetc, Top Ten Reviews and Country Life. And she's a winner of the PPA's Digital Content Leader of the Year. A homes journalist for two decades, she has a strong background in technology and appliances, and has a small portfolio of rental properties, so can offer advice to renters and rentees, alike.