Do solar panels reduce cooling costs and prolong commercial roof life?
Solar panels on commercial buildings are well known for cost-savings and adding to an organisation’s sustainability profile. What is less known is their ability to cool buildings and prolong commercial roof life. This article explores these topics.
In addition to cutting building electricity costs by replacing grid-purchased power, the installation of solar panels is known to provide additional valuable benefits of (a) reducing cooling costs by solar panels blocking sunlight, and therefore reducing solar heat hitting the roof and transferring into the building, and (b) prolonging the roof life for the same reason, a reduction of damaging sunlight (UV rays).
From American research conducted by University of San Diego Engineering Department, panels essentially act as roof shades:
“Rather than the sun beating down onto the roof, which causes heat to be pushed through the roof and inside the ceiling of the building, photovoltaic panels take the solar beating. Then much of the heat is removed by wind blowing between the panels and the roof.
Depending on your roof thermal properties, you can expect a large reduction in the amount of energy you use to cool your residence or business.”
Savings in cooling costs amounted to generating five percent more solar energy than the panels are actually producing.
Solar Panels Keep Buildings Cool, University of San Diego, click here for article.
Prolonged Roof Life
As stated in PerformancePainting.com, keeping a roof in top condition helps to preserve the rest of the structure. An essential requirement is to protect the roof surface from UV rays, which “can damage a roof's structure faster than almost anything.” When UV rays hit the surface of a metal roof, they break the paint layer down by altering its structural makeup.
A solar panel system is believed to extend the life of the roof membrane due to the lower degree of thermal expansion and reduced UV exposure. Research conducted by Sandia National Laboratories found the indirect benefits of solar include potential increase in roof life due to roof shading from the PV system. There is no data currently available as to number of years likely extension, but their research referred to other studies estimating a 10-year increase in life given above benefits.
Increased Roof Life and HVAC Savings from Solar PV System, Performance Painting, click here for article.