“Why solar modules flag during summer”

Solar modules provided about one-third of Germany’s power in June but fell short of reaching record output volumes despite seemingly perfect weather conditions, Ralph Diermann writes on Spiegel Online. The country’s 1.6 million PV modules produced 30.6 gigawatt (GW) on 30 April, almost as much as on the current peak day 27 May, when solar power systems generated 30.7 GW and solar radiation on average is much stronger, Diermann says. “Solar modules lose electric tension when they become hot,” which brings down their capacity, explains Fraunhofer ISE researcher Ralf Preu. At 35 degrees Celsius, their capacity is roughly six percent below what they produce at 20 degrees, he says. “This nullifies the advantage of stronger solar radiation,” Diermann writes.

Read the article in German here.