Solar photovoltaic (PV) power is a great option when looking to reduce your energy bills and carbon footprint. As with any project for your home, there are several factors that need to be considered, including if your roof is compatible. A roof-mounted solar system is a great option, as it is the most cost effective, and it helps to extend the lifespan of your roof. However, not all roofs are ideal for a solar system. There are several factors that go into determining if your roof is a good fit for a solar system. These factors include roof orientation, pitch, roof components, material, load bearing, shading, and age. While your roof does not need to be a perfect fit in all these categories, as very few are, it is a good idea to be aware of how all these factors can affect the placement and size of the solar system for your home.
Roof Orientation – The roof plane that is best for a solar system is one that is facing south. This allows the panels to get the optimal amount of sun. The closer the direction the roof is to 180 degrees south the more efficient the solar system will be at capturing the sun’s rays and converting them into energy. (See the article in the January 2019 issue of G.E.T. “Non-traditional Solar Orientation” for other solar array orientation solutions http://www.greenenergytimes.org/2019/01/15/non-traditional-solar-orientation/).
Pitch – The ideal angle (slope) for your roof is between 30 and 45 degrees from horizontal. This allows the panels to be at the optimal angle to absorb the energy from the sun when it is most seasonally advantageous for maximum production of your electricity.
Vents, Chimneys, and Dormers – If possible, you’ll want to avoid installing solar panels near any vents, chimneys, or dormers. These elements can cause shading on the panels which can slightly reduce energy production.
Roof Material – The best roof materials for a solar system are asphalt shingles or metal. This is due to their durability and long lifespan. Slate tiles and cedar shingles are more fragile, and so it is not recommended to install panels and their supports on them. Therefore, most solar installers will only install on asphalt shingle, standing seam and corrugated metal roofs.
Load Bearing – On average, solar panels add an additional three pounds per square foot. The average roof should be able to withstand the additional weight of the panels. It is important to note that if a roof installation alters the load significantly, or unevenly, an engineer should be consulted.
Shading – While we love beautiful trees in our yards, it is preferable for them to be in a spot that won’t cast any shadows on the solar panels. Therefore, the best roofs have minimal shading from trees in the yard.
Age – If your roof needs to be replaced in the next eight to ten years, it’s a good idea to have it replaced before you have your solar system installed. Once installed, solar panels protect your roof, at least the area of the roof that they cover, from the elements that can cause damage to it and this can extend the life of the roofing.
Solar systems are a great investment to make for your home and for the environment. When selecting a solar installer, bring up these factors that determine your roof compatibility for a solar system. They should be able to discuss them with you and help you determine how a solar system would be best positioned on your roof.
When making the switch to solar, understanding the compatibility of your roof with a solar system is a great first step in producing your own clean energy.
Taylor Kimbrell is the Vice President of Sales and Marketing for Apex Solar Power and Roofing in Queensbury, NY. Learn more at www.apexsolarpower.com / 518.309.2786.