Solar Lesson #13

Viridis Energy Learning Center

Home  Learning Center  Is My Roof Good For a Solar Power System?
Is My Roof Good For a Solar Power System?

Is My Roof Good For a Solar Power System?

As people begin the process of researching a potential Solar PV system there are some popular questions that come up. Viridis Energy has listed some of the most popular questions for you below.

1.) Which way does your roof face?
Solar PV panels are most effective on a broad, south facing roof (at least in the northern hemisphere). Ideally, they should face true south, which is a slightly different direction from the magnetic south you would find with a compass. An easy way to find out if your roof, and thus your property, is good for solar is to look it up on Google Maps. If you show the grid, it will tell you which direction true south is.

If you aren’t able to orient your panels to true south, southeast and southwest facing panels will also work and using a rack will help you to get the best orientation. If you aren’t able to manage a southern exposure on your roof, east and west exposures are still possible depending on shading. Even when solar panels aren’t facing directly south, they can still produce significant amounts of electricity, even in locations that don’t receive abundant sunlight. Also, if your roof orientation isn’t the best, you still have the option of mounting your panels on the ground or on another building like a shed or garage.

2.) How much shade is there on your roof?
Shade can affect the performance and output of your solar panels so you’ll need to assess how much shade your roof receives and for how much of the day. Shade can be the result of other buildings, your own chimney, or from trees around your house. Your installer can help you to assess the impact of your particular situation. There’s not much you can do about other buildings or your chimney, but you can look into the possibility of removing or trimming trees to create less shade.

3.) What type of roof do you have?
Solar panels are compatible with most roofing materials, but some are better for solar than others. The 5 best roof types for solar are Metal standing seam, Standard clay tile and Spanish tile, Asphalt, EPDM rubber, and TPO and PVC.

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

4.) What shape and size is your roof?
It’s easiest to install panels on a large square roof. A general rule of thumb is that for each Kw of your system size, you will need about 100 square feet of roof space. Keep in mind, that things like dormers, turrets and skylights will affect the amount of available space.

5.) Is your roof flat or sloped?
Flat roofs are fine. If your roof is sloped, the best angle is between 30 and 40 degrees. Keep in mind, that for panels to be self-cleaning, they should be at a minimum of 15 degrees. The maximum angle is 40 degrees (any steeper and performance will not be efficient).

6.) How old is your roof?
Solar panel systems can last for 25-40 years so you’ll want to make sure that your roof is in good shape and won’t need to be replaced in the near-term.

If your roof is not suitable for Solar
Viridis Energy can build you a brand new roof or repair your existing roof. If that is not an option we also specialize with installing ground mounted Solar PV Systems! Request your FREE quote below!