Flat Roof Solar Panels

Solar Panel Image
  • Free Expert Advice
  • Instant Quote
  • UK's Lowest Prices
  • Fast Installation
  • Rated "Excellent" on TrustPilot
Last Updated on 11th September 2024

Can You Put Solar Panels On A Flat Roof?

Many people assume that installing solar panels on a flat roof is impractical or even impossible. This misconception often stems from the belief that solar panels require a sloped surface to effectively capture sunlight.

However, the reality is quite different. Flat roofs are suitable for solar panel installations and offer unique advantages such as flexibility in orientation, easier installation in many cases and a more discreet appearance.

In this article, we will explore the feasibility, benefits and considerations of placing solar panels on flat roofs.


Solar Panels On A Flat Roof - How Does It Work?

As mentioned previously, solar panels can be installed on flat roofs and offer a viable alternative to traditional pitched roof installations. While flat roofs present some unique challenges, they also provide certain advantages for solar panel systems.

To maximise efficiency on a flat roof, solar panels are typically mounted on frames that tilt them at an optimal angle. This angling helps capture more sunlight and allows for self-cleaning during rainfall. The mounting system also ensures proper spacing between panel rows to prevent shading and allow for maintenance access.

Ballasted mounting systems are often also used to secure solar panels on flat roofs. These systems use heavy weights to secure the panels and do not penetrate the roof surface. While this adds to the initial expense, it can simplify installation and potentially reduce labour costs.

Despite this, flat roof installations do have some drawbacks. They typically require more roof space per kilowatt of capacity due to the need for spacing between panel rows. Also, flat or low-slope roofs may be more susceptible to water pooling and debris accumulation therefore requiring more frequent cleaning and maintenance.

Despite these challenges, flat roof solar panel systems can be just as effective as their pitched roof counterparts when properly designed and installed. The key is to work with experienced installers who can address the unique requirements of flat roof installations such as Glow Green.


What Are The Advantages And Disadvantages To Flat Roof Solar Panels?

As mentioned above, flat roof solar panels offer flexibility in panel orientation but there are some drawbacks to consider. Here are some pros and cons:

Advantages

  • Easier installation - The flat surface allows for simpler and safer installation processes without the need for complex scaffolding.

  • Reduced labour costs - If no scaffolding is required, labour costs should be reduced significantly.

  • Easier maintenance - Flat roofs provide better access for cleaning and repairs compared to sloped roofs.

  • More aesthetically pleasing - Panels on flat roofs are likely less visible from street level which maintains a home's appearance.

  • Self-cleaning potential - When angled correctly, rain can still help clean the panels similar to sloped roof installations.

  • Versatility in mounting options - Installers can use various methods like ballasted systems or penetrating mounts to secure panels.

Disadvantages

  • Mounting systems increase costs - The specialised mounting systems and stands required for flat roof installations can increase upfront expenses.

  • Space limitations - Due to the need for tilted frames and spacing to avoid shading, flat roof solar panels generally take up more space.

  • Weather vulnerability - Flat or low-angled panels may be more susceptible to snow accumulation and water pooling.

  • More cleaning may be required - While easier to access, flat roof systems may require more cleaning due to the tendency of flat surfaces to accumulate more water, dust and debris.

  • Not all flat roofs are suitable - Some flat roofs may not have the structural integrity or load-bearing capacity required to support solar panels and their mounting systems. For more information, you can read our guide on solar panels and roof suitability.

  • Warranty concerns - Some manufacturers' warranties may become void if panels are installed flat without proper mounting systems. We strongly recommend that you check your specific warranty before proceeding with the installation.


Will My Flat Roof Need To Be In Good Condition?

Yes, your flat roof must be in good condition for solar panel installation. A thorough assessment of the roof's structural integrity is essential to ensure it can support the weight of the solar panels and their mounting systems. If the roof has existing issues such as leaks, damage or inadequate drainage, these problems need to be addressed before installation to prevent further complications.

Also, the roof should have sufficient space to accommodate the solar panels while allowing for proper spacing to avoid shading and ensure maintenance access. Consulting with a qualified solar installer, such as Glow Green, can help determine if your flat roof is suitable and what modifications may be necessary to support a flat roof solar panel system effectively.


What Is The Best Angle For Flat Roof Solar Panels?

The best angle for flat roof solar panels typically ranges between 20 to 50 degrees. This angle provides a good balance between maximising energy production throughout the year and accommodating seasonal variations in the sun's position.

It's worth noting that adjustable mounting systems exist allowing for seasonal angle optimisation but these are often cost-prohibitive for most installations. As mentioned already, the chosen angle not only affects energy production but also aids in self-cleaning by allowing rainwater to run off the panels reducing maintenance needs.

When installing solar panels on a flat roof, it's crucial to use appropriate mounting frames to achieve this optimal angle, as well as using a trusted installer to ensure panels are fitted at the best angle possible.


How Does The Weather Impact Flat Roof Solar Panels?

We've already mentioned that flat or low-angled panels can be impacted by snow and water pooling, however, a mounting rack can mitigate this issue.

If you live in an area prone to strong winds, it is crucial that solar panels are properly secured to prevent damage or dislodgment. Properly pinned-down panels minimise the risk of being lifted or shifted by gusts which can compromise their efficiency and structural integrity. Utilising robust mounting systems, such as ballasted or anchored racks, ensures that the panels remain stable even during severe weather conditions.


Will I Need Planning Permission?

In most cases, you will not need planning permission to install solar panels on a flat roof in the UK. As of December 2023, the government extended permitted development rights to include solar panel installations on flat roofs making it easier for homeowners to adopt solar energy.

However, to ensure compliance, it's always recommended to consult the National Planning Portal for up-to-date information and work with a reputable, MCS-certified solar installer who is familiar with local regulations.


How Much Will It Cost To Install Flat Roof Solar Panels?

Installing solar panels on a flat roof generally costs more than on a pitched roof due to several factors. First, flat roof installations require specialised mounting systems to tilt the panels at the optimal angle for sunlight absorption which adds to the overall cost. Also, these installations often necessitate extra materials for waterproofing and reinforcement to support the solar panel system further increasing expenses.

As discussed before, the weighted systems, such as ballasted racks used to secure panels contribute to the overall cost. While the initial investment for flat roof solar installations is typically higher, they can still offer long-term energy savings and advantages in terms of maintenance accessibility and aesthetic appeal.

How Much Money Could I Save A Year?

A household with a 3.5 kilowatt-peak (kWp) system could save between £130 and £310 a year at the current Energy Price Cap rates. However, these savings can vary depending on factors such as your location, energy consumption patterns and the efficiency of your solar panel system.

It's important to note that there isn't a significant difference in cost savings between sloped and flat roof solar installations once the systems are operational. The main variations lie in the initial setup and installation processes. Over time, both types of installations can provide substantial reductions in electricity bills and contribute to lowering your carbon footprint.

As energy prices continue to fluctuate, the potential savings from solar panels, regardless of roof type, may increase making them an increasingly attractive investment for homeowners.


Things To Know Before Buying Solar Panels

Solar Panels Buying Guide

Discover key factors to consider before buying solar panels.

Learn More
Best Solar Panel Installers

Best Solar Panel Installers

Find out more about the top 10 solar panel installers in the UK.

Learn More
Solar Panel Quotes

Solar Panel Quotes

Learn about the process of getting a quote, considerations and FAQs.

Learn More

Flat Roof Solar Panels FAQs

Are flat roof solar panels as efficient as those on pitched roofs?

Yes, flat roof solar panels can achieve efficiency levels comparable to those installed on pitched roofs provided they are correctly installed using tilted mounting systems to maximise sun exposure.


Do flat roof solar panels require more maintenance?

Flat roof solar panels may require slightly more frequent cleaning due to potential dust and debris accumulation but they are often easier to access for maintenance compared to pitched roof installations.


Can flat roof solar panels withstand strong winds?

Yes, when properly installed with appropriate mounting systems and ballasts, flat roof solar panels can withstand strong winds as effectively as pitched roof installations.


Will installing solar panels damage my flat roof?

When installed correctly by professionals, solar panels should not damage your flat roof. In fact, they can provide an additional layer of protection for the roof surface.


How do I know if my flat roof is suitable for solar panels?

A professional solar installer can assess your roof's suitability by checking its structural integrity, sun exposure and available space as well as considering any potential shading issues.