Solar panels tested in Augusta and other cities lose efficiency as temperatures rise, but still produce more power during summer months because sunshine is more abundant, according to data gathered during an 18-month pilot project.
“These are some of the preliminary results,” said Carol Boatright, a spokeswoman for Georgia Power Co., which launched the study in February 2011 as a joint effort with the Electric Power Research Institute.
Georgia Power placed seven 3-by-5-foot panels in Augusta, with similar clusters installed in Rome, Valdosta, Macon, Columbus, Savannah and Conley.
Each panel, under full sun, can generate about 200 watts of electricity fed directly into the utility’s commercial grid.
Analysis of the panels’ performance showed, in some cases, a nearly 10
percent decrease in relative output for summer versus winter months, Boatright said, while the total output was greater during the summer because of longer days and the sun being higher in the sky.
The experiment also collected data to be used to identify challenges associated with adding large amounts of solar generation onto the commercial electric grid. The findings indicate the amount of solar power that can be hosted varies according to the infrastructure available in specific locations.
Another facet of the study involved developing new ways to measure solar variability – the amount of time skies were clear versus overcast.
“These different ways of measuring variability will be able to be used to compare our territory with locations in the Southwest and the Northeast,” she said.
In general, winter and fall days are most likely to be fully clear or completely overcast, while summer and spring have more days with mixed or changing conditions.
The objective of the study was to determine how solar generation would fit into the company’s portfolio – now dominated by coal (67 percent), nuclear (21 percent), oil and gas (10 percent) and hydropower (2 percent), according to a company fact sheet.
“We will have more specifics at the end of the year as EPRI finalizes their research,” Boatright said, adding that the solar panels in Augusta and other venues will remain installed and operational, leaving Georgia Power and Southern Co. with options for ongoing and future research.