Solar Panel Kits and more...

We’ve posted a number of times about solar powered air conditioning, also known as solar cooling. It should come as no surprise that solar electricity generated by photovoltaic (PV) panels can be used to operate A/C systems and solar attic fans.  But solar panels cooling effects go beyond just creating solar energy.

Can solar panels cool buildings?

At UC San Diego this year, professor Jan Kleissl, professor of engineering, and a group of students were preparing  for a upcoming conference at the Powell Structural Systems Laboratory.  The Laboratory rooftop is substantially covered with solar panels, some of which are tilted, and some of which are flush with the roof.

Using a thermal infrared camera, the students took photographs of the entire roof surface, comparing areas that were covered with solar panels with bare patches.  The reason?  To confirm the hypothesis that the solar panels themselves were cooling the building.

After initial results, the group launched a scientific study to determine the extent of solar panels cooling effects. The study will be published in an issue of the industry journal Solar Energy.

The study showed that not only do solar panels generate clean solar energy for homes or workplaces, they can also cool it. The team discovered the Laboratory ceiling under the solar panels was 5° F cooler than it was under the sections of exposed roof. Conversely, at night the panels help to retain heat.

How do solar panels cool buildings?

The UC San Diego research time discovered that rooftop solar panels act as roof shades. Without solar panels, bare roofs allow radiant heat to be pushed indoors from the roof.  When solar panels cover the roof of a structure, they absorb much of the heat.  Flat panels are effective, but tilted solar panels allow air circulation between the structure and the roof, with additional cooling benefits.  As much as a 38% reduction of heat can be achieved with solar panels on a roof.

This can translate into energy savings, with less electricity required to keep interiors cool.  The team reported that the amount saved on cooling was equivalent to getting a 5% discount on the price of solar panels!