Can You put Solar Panels on a Flat Roof?

Solar Panels

It is perfectly safe to install solar panels on a flat roof. In fact, flat roof solar panels are the perfect way to make use of all that wasted space.

Instead of the sun beating down on your flat roof (and reducing its lifespan), you could be generating electricity for your home and saving money!

If you're not sure what steps you need to take, the Roofing Association will help you every step of the way.

This article will explain all you need to know about buying a solar panel system, what equipment you might need and a few tips about maintenance.

If you've already done a considerable amount of research and you're ready to get a few quotes, click here.

solar panels on flat roof

What are the Benefits of Flat Roof Solar Panels? 

Providing that your existing flat roof is in good condition, investing in solar energy will be one of the best purchases you ever make. Here are the five main benefits of installing solar panels on a flat roof:

· Save money by generating your own electricity instead of buying it from a supplier

· Feel good by knowing you're using a green form of energy

· Flat roof systems are mostly out of sight and cannot be seen from the street

· The panels are much easier to install because of easy access and more space to manoeuvre

· Have the panels installed by an MCS certified company and take advantage of the government's feed-in tariff

How Much does it Cost to install Solar Panels on a Flat Roof? 

The average cost of installing flat roof solar panels is around £825 per Kw. The average cost of solar panel installation on a pitched roof is around £1250 per Kw.

As you can see, installation costs on flat roofs are much lower than pitched roofs. Bear in mind that these are rough estimates. Prices will depend on which mounting technique you choose and how many panels you need.

So why does it cost less to install panels on flat roofs than pitched roofs? Well, the answer is simple. The labour costs for flat roof solar panel installations is lower than a pitched roof. Approximately 10% of the cost of installing solar panel systems is attributed to the cost of labour and safety equipment.

Solar panel installers have much more freedom to move on a flat surface. The freedom of movement means they don't need to use expensive safety equipment like on a sloped roof.

Keep in mind that the flat roof solar panels have to be in a tilted position to be able to absorb the sun's rays and generate electricity.

You will have to buy tilted mounting racks to keep the panels in the correct position. The cost of installing solar panel mounting racks will vary depending on what type of flat roof you have.

solar panels on flat roof uk

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How much Money Could you Save by Installing Solar Panels on a Flat Roof? 

If you have a typical 4 kWp solar PV system, it is estimated that you will save anywhere between £80 and £230 per year. Although that might not sound like a lot of money, you're also benefiting from free electricity.

Try to think of solar energy as an investment. Every year that passes is another year of savings that will inevitably pay for the cost of the solar array.

Solar thermal systems are also a good investment if you want to save even more money.

How do Solar Panel Systems Work on a Flat Roof? 

It is much more common to see flat roof solar systems installed on commercial buildings. It didn't take long for savvy commercial property owners to realise that they were wasting this prime piece of real estate (the roof). However, the last decade has seen an explosion in domestic properties investing in solar panel array. Once people realised they could generate free electricity, they were eager to invest.

Domestic solar panel systems must be able to withstand strong winds. Another requirement is self cleaning panels to maximise electricity production. The correct positioning of the solar panels is crucial. If the panels are not in the correct position, they won't be able to absorb as much energy from the sun.

Once the flat roof solar panels have been installed, they will absorb energy from the sun and convert it into electricity. The one drawback with stationary flat roof solar panels is that they can't turn to face the sun's direction.

This is where an automatic solar tracker system comes into play. A solar tracker will allow the panels to turn to always face the sun and absorb its rays.

Solar Panels on a flat roof commercial building

Here are the Pros and Cons of Having Solar Panels on top of a Flat Roof 

Having renewable energy installed on any type of property has a few positives and negatives. However, installing solar panels on a flat roof comes with a few hurdles that you'll have to address.

The Positive Points of having Solar Panels on a Flat Roof

· you'll be using green energy and reducing your carbon footprint

· you can generate your own electricity and save some money

· People can’t see the panels when walking past your home

· installation and maintenance is much easier

· ease of access means the cost of labour will be lower

· they don’t need much maintenance

The Negative Points of having Solar Panels on a Flat Roof 

There’s only a few negatives to having a flat roof system, and a mounting system eliminates most of these issues.

· The warranty for solar panels on a flat roof can become void. The manufacturer's installation guide stipulates that the panels must not be laid flat. Rainwater cannot run off the panels if they are flat. If rainwater is left to sit on the panel's surface, it will degrade the silicone sealant and find its way inside.

· Dirt accumulates on the surface of the solar panel. Pitched roof solar panels usually don't have a problem with dirt collecting on the surface. However, solar panels that are laid flat will accumulate a layer of dirt and reduce their efficiency.

· The panels will not reach their full potential if they are not positioned at the correct angle. Panels fitted on a slanted roof are in the perfect position to absorb as much of the sun's rays as possible. However, solar panels that are laid flat down on top of a flat roof will not generate as much electricity.

If you want to avoid all of the disadvantages, you will have to invest in a mounting system. The average cost of racking for solar panels is approximately 3% of what you are paying for your flat roof solar system. The cost of solar panel racking can vary depending on which brand you choose and how many you need to buy.

Do You need Planning Permission to Install Solar Panels on a Flat Roof?

Flat roof solar panel installation falls under permitted development so you shouldn’t need to apply for planning permission. As long as your panels do not exceed the highest part of your roof, you should be fine.

If you are the property owner, you are responsible for following the guidelines. It is strongly recommended that you contact the planning portal to make sure you are following the correct procedures.

What is the Best Angle for Solar Panels on a Flat Roof?

According to Stanford University, the best angle for flat roof solar panels is 37 degrees. The correct positioning of flat roof solar panels will help to maximise the absorption of the sun's rays.

Another benefit of positioning the panels at 37 degrees is that it helps clean the panels when it rains. A professional installer will find the best position for your panels.

How to Stop Flat Roof Solar Panels from Moving in Strong Winds 

If you've ever experienced strong winds ripping slates off a roof, you might be worried about how strong winds could affect your solar panel system. Luckily, manufacturers have developed two methods to stop strong winds from damaging flat roof solar panels.

The first method is to fix the panels to the structure of the flat roof. Fixing solar panels to the roof structure of a flat roof involves penetrating the roof's surface and attaching support brackets.

The second method involves placing heavy slabs along the roof and placing ballast frames on top of the slabs. The solar panels are then fixed to the ballast frames.

Does my Flat Roof have to be in Good Condition for Installing Solar Panels? 

If you suspect your flat roof is in poor condition, we recommend you get a roof inspection before investing your money into solar panels. The majority of flat roofs are made of traditional felt, which has a lifespan of approximately 15 years.

So if your flat roof is over 10 years old, it would definitely be worth replacing it before installing solar panels.

The same applies if you are planning to build an extension on your home and place solar panels on the flat roof. Talk to your builder about installing a solar panel flat roof on an extension, and he will be able to advise the best type of material to use on the roof.

Get a FREE No Obligation Quote for Flat Roof Solar Panel Installation in Your Area 

If you would like to get a few quotes to have solar panels installed, head over to our quote form. Enter your details into the form, and we will arrange a visit to your home and provide you with a quote.

It's all free of charge and won't cost you a penny!

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