Navigation Links
Solar Panels Keep Buildings Cool
Date:7/18/2011

Those solar panels on top of your roof aren't just providing clean power; they are cooling your house, or your workplace, too, according to a team of researchers led by Jan Kleissl, a professor of environmental engineering at the UC San Diego Jacobs School of Engineering.

In a study in an upcoming issue of the journal Solar Energy, Kleissl and his team published what they believe are the first peer-reviewed measurements of the cooling benefits provided by solar photovoltaic panels. Using thermal imaging, researchers determined that during the day, a building's ceiling was 5 degrees Fahrenheit cooler under solar panels than under an exposed roof. At night, the panels help hold heat in, reducing heating costs in the winter.

"Talk about positive side-effects," said Kleissl.

As solar panels sprout on an increasing number of residential and commercial roofs, it becomes more important to consider their impact on buildings' total energy costs, Kleissl said. His team determined that the amount saved on cooling the building amounted to getting a 5 percent discount on the solar panels' price, over the panels' lifetime. Or to put it another way, savings in cooling costs amounted to selling 5 percent more solar energy to the grid than the panels are actually producing for the building researchers studied.

Data for the study was gathered over three days in April on the roof of the Powell Structural Systems Laboratory at the Jacobs School of Engineering with a thermal infrared camera. The building is equipped with tilted solar panels and solar panels that are flush with the roof. Some portions of the roof are not covered by panels.

The panels essentially act as roof shades, said Anthony Dominguez, the graduate student lead on the project. 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. The benefits are greater if there is an open gap where air can circulate between the building and the solar panel, so tilted panels provide more cooling. Also, the more efficient the solar panels, the bigger the cooling effect, said Kleissl. For the building researchers analyzed, the panels reduced the amount of heat reaching the roof by about 38 percent.

Although the measurements took place over a limited period of time, Kleissl said he is confident his team developed a model that allows them to extrapolate their findings to predict cooling effects throughout the year.

For example, in winter, the panels would keep the sun from heating up the building. But at night, they would also keep in whatever heat accumulated inside. For an area like San Diego, the two effects essentially cancel each other out, Kleissl said.

The idea for the study came about when Kleissl, Dominguez and a group of undergraduate students were preparing for an upcoming conference. They decided the undergraduates should take pictures of Powell's roof with a thermal infrared camera. The data confirmed the team's suspicion that the solar panels were indeed cooling the roof, and the building's ceiling as well.

"There are more efficient ways to passively cool buildings, such as reflective roof membranes," said Kleissl. "But, if you are considering installing solar photovoltaic, 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."

If additional funding became available, Kleissl said his team could develop a calculator that people could use to predict the cooling effect on their own roof and in their own climate-specific area. To further increase the accuracy of their models, researchers also could compare two climate-controlled, identical buildings in the same neighborhood, one with solar panels, the other without.


'/>"/>

Contact: Ioana Patringenaru
ipatrin@ucsd.edu
858-822-0899
University of California - San Diego
Source:Eurekalert  

Related biology news :

1. Team New Jersey to make precast concrete solar house reality
2. U of T researchers crack full-spectrum solar challenge
3. Efficiency record for flexible CdTe solar cell due to novel polyimide film
4. Solar inverters: Losses are cut in half
5. New solar product captures up to 95 percent of light energy
6. Solar cells more efficient than photosynthesis -- for now
7. NRELs multi-junction solar cells teach scientists how to turn plants into powerhouses
8. MIT researchers use virus to improve solar-cell efficiency
9. Toward a more efficient use of solar energy
10. Switching to solar
11. Toward a green grid for delivering solar and wind-based electricity
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Solar Panels Keep Buildings Cool
(Date:4/28/2016)... BANGALORE, India , April 28, 2016 ... of Infosys (NYSE: INFY ), and Samsung SDS, ... partnership that will provide end customers with a more ... payment services.      (Logo: http://photos.prnewswire.com/prnh/20130122/589162 ) ... financial services, but it also plays a fundamental part in ...
(Date:4/26/2016)... LONDON , April 26, 2016 /PRNewswire/ ... Systems, a product subsidiary of Infosys (NYSE: ... partnership to integrate the Onegini mobile security platform ... http://photos.prnewswire.com/prnh/20151104/283829LOGO ) The integration ... security to access and transact across channels. Using ...
(Date:4/19/2016)... -- The new GEZE SecuLogic access control ... system solution for all door components. It can be ... interface with integration authorization management system, and thus fulfills ... dimensions of the access control and the optimum integration ... considerable freedom of design with regard to the doors. ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... -- Houston Methodist Willowbrook Hospital has signed a ... serve as their official health care provider. As ... provide sponsorship support, athletic training services, and most ... athletes and families. "We are excited ... to bring Houston Methodist quality services and programs ...
(Date:6/23/2016)... 2016   EpiBiome , a precision microbiome engineering ... debt financing from Silicon Valley Bank (SVB). The financing ... advance its drug development efforts, as well as purchase ... "SVB has been an incredible strategic partner to us ... bank would provide," said Dr. Aeron Tynes Hammack ...
(Date:6/23/2016)... 2016 Apellis Pharmaceuticals, Inc. today announced ... of its complement C3 inhibitor, APL-2. The trials ... dose studies designed to assess the safety, tolerability, ... in healthy adult volunteers. Forty subjects ... single dose (ranging from 45 to 1,440mg) or ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... ... is exhibiting at the Pennsylvania Convention Center and will showcase its product’s latest ... ClinCapture will also be presenting a scientific poster on Disrupting Clinical Trials in ...
Breaking Biology Technology: