Contractor Blog

Viridian Solar Panels and the Benefits of In Roof PV

George Riley · 20 Sep 2019

While solar panels are traditionally retrofitted to an existing rooftop, it’s becoming more common (especially in newbuilds) to integrate the panels into the roof itself. With in roof PV, you end up with a sleeker, more attractive result.

One of our favourite brands of integrated solar is Viridian. Manufactured here in the UK, Viridian solar panels have a bespoke mounting system to embed them in the rooftop with a sleek, low profile.

Case study

Viridian is particularly popular with housebuilders - they’re winning contracts with many large firms. Builders appreciate that the integrated panels are so easy to install, displace some of the traditional roofing materials required, and boost the building’s energy performance and desirability.

domestic solar panels

Here you can see some of the panels we installed for Millgate Homes in Winchester, back in 2017. They complement the design of the properties beautifully, and who wouldn’t want to buy a house that generates its own electricity?

Benefits of Viridian panels

The advantages of Viridian solar panels (and many other forms of in roof PV) are:

  • Appearance - more flush and stylish than most on roof systems. Viridian mounting keeps all the modules evenly spaced for a very neat finish.
  • Bird protection - while regular PV has a gap underneath that makes an attractive home to nesting birds (unless adequately guarded), sitting in roof avoids this issue entirely.
  • Ease of install - see more details below.
  • Maintenance - if the roof requires maintenance at any point during the solar system’s lifetime then above roof panels would have to be disconnected and removed to access the tiles beneath. With in roof PV, maintenance can happen around the system without disturbance.
  • Superior certification against fire, wind etc - see more below.

Installing Viridian PV

One reason integrated PV is favoured by housebuilders is that regulations for new roofs or extensions now require each individual tile to be fixed with nails or clips. This makes fixing above roof solar more difficult when tiles have to be removed, or requires a more arduous process (PV installer adds their hooks, roofer puts in the tiles, installer has to come back to attach the panels). But with integrated PV, the installer can fit the panels and flashing, then leave the roofer to tile around them.

Wind uplift for in roof PV

Wind is an important factor when designing a rooftop PV system. It’s vital that the mounting prevents the modules from being torn off the roof by the wind. The wind load can be higher when the panels are raised further from the roof’s surface, which is why flat roof panels need ballasting and in roof panels have greater wind resistance. The particular wind load for a building will depend on its geographic location, height and surrounding shelter.

Viridian wind uplift

Source: Viridian.

Viridian panels have been certified to withstand a wind uplift pressure more than 4 times higher than their competitors. This makes it suitable for exposed locations like coastal towns, high altitudes and roof edges.

Drawbacks of integrated solar

The main downside of integrated systems like Viridian are the lack of ventilation. As solar cells absorb the sun’s energy, they heat up; as they heat up, they become less efficient. A cool breeze blowing underneath the panel can be great for keeping the temperature down, which is why ground mounted and above roof systems work well.

In roof systems don’t have this advantage, so there will be a drop in performance. But by how much? Viridian conducted a test with Cambridge University and found their panels would generate 3% more if installed above roof, and 6% more if in a free standing ground mount. So you can expect around a 3% lower output for in roof vs on roof PV.

Find out more

If you have a project where you’re interested in Viridian or other integrated solar panels, please get in touch to discuss with our team. Having designed and installed over 2,000 systems, they know their stuff!

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Topics: In roof solar panels, Solar PV