Solar keeps your house cooler, too!
Now, here’s an interesting fact. In addition to reducing your electricity bills and enhancing the value of your house by an average of $17,000, putting solar on your roof actually keeps your house cooler. That’s according to a research team led by Jan Kleissl, a professor of environmental engineering at the University of California, San Diego Jacobs School of Engineering.
Typically, the sun beats down onto a roof, pushing heat through the roof and inside the ceiling of a building. But when solar panels are in place, the panels take the direct hit of the sun and filter the heat. The effect is even greater when the panels are mounted and tilted, allowing air to circulate below the panel and further dissipate the heat. The researchers determined that solar panels reduce the heat reaching the roof by 38%, making the building’s ceiling five degrees cooler under solar panels than under exposed roof.
Conversely, in the winter, the panels would keep the sun from heating up the building, but would also help to keep in whatever heat had accumulated inside the building. These effects are likely to balance each other out from an energy use perspective.
Although the study was limited, the team is publishing what they believe is the first ever peer-reviewed measurements of the cooling benefits provided by photovoltaic panels in an upcoming issue of the Journal of Solar Energy. The data was gathered over three days in April on the roof of the Powell Structural Systems Laboratory at the University of California, San Diego using a thermal infrared camera. On that roof, there are some areas covered with solar panels that are mounted and tilted, some areas with solar panels that are flush with the roof, and some areas without solar panels.
The researchers concluded that the building’s energy savings from solar panels equated to getting a 5% discount on the price of the panels over their lifetime. Or another way of thinking about it is that it’s like selling 5% more electricity to the grid than the panels are actually producing.
Just one more reason to go solar now!