The 5 Best Roof Types for Solar Power

When you start thinking about installing a solar photovoltaic system in your home, one of the first questions you ask yourself is “Is my roof suitable for solar panels?” Solar panels are compatible with most roofing materials, but some are better for solar power than others.

Solar panels are compatible with most roofing materials, including:

  • metal roofs: The “seams” of many metal roofs facilitate the installation of photovoltaic solar panels. In most cases, the systems can be installed without drilling holes in the roof using fixing systems anchored in the joints. Metal roofs are also good insulators and very energy efficient, making homes with metal roofs suitable for solar installation.
  • Standard clay tile and spanish tile: Solar installers can easily work on clay tile roofs. Conventional brackets can be integrated into tile roof solar installations, and some companies also manufacture solar panel brackets that are integrated with clay tiles to make installation even easier.
  • Asphalt: Solar installers can easily work on asphalt roofs, without worrying about causing damage. Standard brackets can be used for solar installations on asphalt roofs.
  • EPDM rubber: rubber ethylenepropylene (EPDM) is used on flat roofs and is most common on commercial buildings. Solar installers working on EPDM flat roofs use a weighted mounting system (called a ballast system), which means they don’t normally have to drill holes in the roof. For this reason, EPDM installations are often less expensive than systems with supports anchored to the roof.
  • TPO and PVC: Like EPDM roofs, thermoplastic polyolefin (TPO) and polyvinyl chloride (PVC) roofs are typically flat and use ballast systems to mount the solar panels. Both TPO and PVC installations are relatively inexpensive.

Certain types of roofs are less compatible with solar energy. It is difficult for solar installers to work on slate and wood roofs, as these materials are brittle and can break. They require specialized mounting components and equipment because installers cannot walk on the roof without damaging it. This means that installations on slate and wood roofs are more expensive.

Image: grieze – Depositphotos.

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Is my roof suitable for solar panels?

The material your roof is made of plays an important role in your home’s suitability for solar energy, but it’s not always the deciding factor.

There are a few other questions you can answer to determine if your home is made for solar power.

1. Where is your roof?

Solar photovoltaic panels are most effective on a large south-facing roof (at least in the northern hemisphere). Ideally, they should face true south, which is a slightly different direction from magnetic south found with a compass.

An easy way to find out if your roof is good for solar power is to look it up on Google Maps. If you show the grid, it will tell you which direction is true south. If you can’t orient your panels to the south, southeast and southwest facing panels will also work and using a rack will help you achieve the best orientation.

If you can’t angle your roof south, it’s also possible to face east and west, depending on the tint. Even when solar panels aren’t facing directly south, they can produce significant amounts of electricity, even in places that don’t receive abundant sunlight.

Also, if the orientation of your roof is not the best, you always have the option of mounting your panels on the ground or in another part of the house such as a garage.

2. How much shade is there on the roof?

Shade can affect the performance and yield of solar panels, so you will need to assess the amount of shade your roof receives and the length of the day. Shade can come from other buildings, your own chimney, or the trees around your home.

The installer can help you assess the impact of your particular installation. You can’t do much about the other buildings or the chimney, but you can consider pruning the trees so there’s less shade.

3. What is the condition of your roof?

Solar panel systems can last between 25 and 40 years, so you need to make sure your roof is in good shape and you won’t need to replace it any time soon. Surely you will also wonder if the panels can damage your roof, in this article we talk about this question.

4. What is the shape and size of your roof?

It is easier to install panels on a large square roof. As a rule of thumb, for every kW of your system size, you will need around 30 square meters of roof space. Keep in mind that things like dormers, turrets, and skylights will affect the amount of space available.

5. Is your roof flat or sloping?

Flat roofs are fine. If your roof is sloped, the best angle is between 30 and 40 degrees. Please note that for the panels to self-clean they must be at a minimum of 15 degrees. The maximum angle is 40 degrees (the steeper the slope, the more inefficient the performance will be).

What to do if your roof is not suitable for solar energy.

There are other solar power options if your roof is not ideal for installing a solar panel system, such as:

  • Install a ground-mounted solar panel system elsewhere on your property.
  • Build a carport with solar panels to power your home and shade your car at the same time.
  • Invest in a solar farm fee, which gives you the benefits of rooftop solar power from a large solar panel installation in your community.

If you shop around and compare options, some of these alternatives may offer the same level of savings you would get with a system on your roof.

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