Solar roof tiles: What are they and how much do they cost?

Solar roof tiles allow you to generate renewable energy for your household without compromising on how your house looks. Unlike traditional large, conspicuous solar panels, solar tiles simply replace – and replicate – your existing slate or terracotta tiles. The only difference? Solar roof tiles will save you money year after year.

As easy as solar roof tiles are on the eye, however, they’re not so easy on the wallet – and they’ll cost you around twice as much as a conventional roof-mounted solar array. They’re also only suitable for new developments or homes undergoing re-roofing – we’ll explain why, along with solar roof tiles’ other main drawbacks, below.

We’ll also explore how solar roof tiles offer a more durable, subtle twist on domestic solar technology – one which can remove some of the stress of obtaining planning permission.

Solar roof tiles – also known as solar slates, solar shingles or photovoltaic (PV) tiles – combine the ability to generate green energy with the functionality of regular roof tiles.

Basically, solar roof tiles do everything normal roof tiles do but with a twist: they convert the sun’s light into clean, renewable energy to light your home and power your appliances. This leaves you less at the mercy of the National Grid – and less prone to power outages or price hikes. It can even slash hundreds of pounds off your energy bill every year.

Unlike traditional roof-mounted solar panels, solar roof tiles aren’t designed to sit on the roof; and, unlike integrated solar panels, they’re not built to be embedded in the roof, either. Solar roof tiles are in fact the roof itself. 

Because of this, solar roof tiles are one of the most subtle domestic solar technologies money can buy in the UK. While the more conspicuous design of on-roof solar panels can lead to planning permission issues (or worse: disagreements with your neighbours), solar roof tiles slot seamlessly into your building’s architecture. So much so that, if you stand back and squint slightly, you won’t even notice the difference.

That said, solar roof tiles aren’t for everyone. The difficulties of the retrofitting process – that is, ripping up your roof to replace your existing tiles with solar ones – means that this solution isn’t ideal for existing homes looking to go solar. Solar roof tiles are, however, ideal if you’re looking to incorporate solar energy generation into a new development (when the roof hasn’t been built yet) or alongside other work to your roof (such as re-roofing, where you’ll be replacing the old tiles and there’s no extra investment required to rip them out).

Solar roof tiles are an emerging, exciting form of domestic renewable technology in the UK, and as they continue their march into the mainstream, they’ll only become more affordable and accessible to the average UK homeowner.

As with working out if solar panels are worth it, the key benefit of solar roof tiles is how much money you can save. By generating your own energy, you can take advantage of solar grants, such as the UK’s Smart Export Guarantee (SEG): a scheme through which a standard 4kW system could earn an average of £228 per year by selling any excess electricity your solar roof tiles make back to the grid. On top of this, there’s also the money you’ll save on your energy bill by not having to purchase as much from mainstream suppliers or having to draw on the National Grid at peak times.

That said, solar roof tiles won’t be right for all homes – or all budgets.

Visual appeal

Solar roof tiles’ top selling point? Their aesthetic appeal. These tiles aren’t designed to stand out but blend in.

Depending on their type, model and quality, solar roof tiles can be indistinguishable from regular roof tiles. That means these chameleonic tiles can help you gain planning permission – especially if your home is situated in a conservation area or is classified as a listed building or World Heritage Site. If that sounds like your home, your solar installation will require planning permission (in contrast to most houses in the UK, which won’t) and there will potentially be a lengthy public consultation process.

As part of this process, the onus will be on you to prove to the relevant local planning authority – typically your local council – that your panels won’t compromise the aesthetic integrity of your home and the surrounding area. In this instance, solar roof tiles’ subtlety and seamlessness can be the difference between your solar installation getting approval and getting a rejection that could take you back to the drawing board.

Want to learn more about another type of solar array that’s easy on the eye? Browse our guide on ground-mounted solar panels to learn whether they’re right for you.

Durable

Despite being smaller than traditional on-roof solar panels, solar roof tiles are more durable and easier to maintain.

Chiefly, this is because solar roof tiles don’t require a mounting system like conventional, bolt-on solar panels do. The gap that mounting system creates between the roof and the solar panels can attract debris, or – even worse – pigeons looking for a place to nest. That gap also means on-roof solar panels can be more prone to wind and weather damage.

Additionally, because they’re part of the roof rather than an addition to it, solar roof tiles are easier to clean and maintain and less likely to lose efficiency due to damage.

Less cost-effective

On average, solar roof tiles cost around twice as much as conventional on-roof solar panels.

This makes them a less-accessible solar solution – particularly for homes operating on tight budgets and amid the UK’s ongoing cost-of-living crisis. It also means that unless you really need them (to push through a particularly difficult planning permission application, for example), solar roof tiles are unlikely to be the best option for your home.

If you’re hamstrung by a tight budget but you love the aesthetic benefits of solar roof tiles, we recommend looking at integrated solar panels.

Integrated solar panels are installed at the felt and batten layer of your roof, so, like solar roof tiles, they sit snugly in your roof for a more subtle, unobtrusive look. However, their price is nowhere near as much as solar roof tiles. In fact, integrated solar panel costs are comparable to that of conventional, on-roof solar panels – making them more suitable for shoestring budgets.

Lower efficiency

Solar roof tiles may look amazing – especially when compared to the more obtrusive mounting of on-roof solar panels – but that comes at a cost: their efficiency level.

Estimates place the average efficiency of solar roof tiles at between 10 and 20%. This is slightly less than traditional monocrystalline solar panels, which are 15 to 25% efficient. Plus, if your solar roof tiles are any colour other than black (or a dark, bluish black), which they might need to be to blend into the existing colour scheme of your home’s exterior, they’ll reflect rather than absorb the sun’s light. This can result in a further reduction of your solar roof tiles’ efficiency rates.

To understand efficiency as it relates to solar energy in more detail, explore how much electricity solar panels generate – and what it might mean for the size of your home’s energy bill.

Not suitable as a bolt-on solution

If you’re looking to start generating your own renewable energy for your household but you’re happy with how your home – and your roof – looks, solar roof tiles won’t be for you.

That’s because solar roof tiles simply don’t work as a bolt-on solar option. They’re not as simple as on-roof panels, which are placed on top of a mounting structure on your existing roof to start generating power straight away. Instead, solar roof tiles need to be factored into a new home development from the first blueprints or fitted as part of a planned re-roofing project. Otherwise, the costs and labour required to retrofit your roof will make installing solar roof tiles unfeasible – not to mention a logistical nightmare!

Also, solar roof tiles are only feasible if you replace your whole roof (especially because, with their reduced efficiency, you’ll need more than one or two tiles or a cluster here or there to meet your household’s electricity needs). This makes them harder to install (and reinstall or uninstall) than traditional solar panels with mounting systems.

As mentioned, solar roof tiles aren’t the most affordable way to power your household with clean, renewable energy. At around double the cost of on-roof solar panels – and with their lower efficiency meaning they produce less electricity than their conventional cousins – solar roof tiles aren’t the most cost-effective approach.

On average, we estimate it’ll take around 19 years before your solar roof tiles pay for themselves. This isn’t just because of the bigger upfront outlay but also because your energy-bill savings – as well as the payments you’ll receive through the SEG by selling your surplus electricity back to the grid – won’t be as high.

Take a look at the table below to explore how much solar roof tiles will cost you, how much they can save you and how long it’ll take you to recoup your upfront solar roof tile investment.