The German government decided to abandon nuclear power after the Fukushima nuclear disaster last year, closing eight plants immediately and shutting down the remaining nine by 2022.
They will be replaced by renewable energy sources such as wind, solar and bio-mass.
Norbert Allnoch, director of the Institute of the Renewable Energy Industry (IWR) in Muenster, said the 22 gigawatts of solar power per hour fed into the national grid on Saturday met nearly 50 percent of the nation's midday electricity needs.
"Never before anywhere has a country produced as much photovoltaic electricity," Allnoch told Reuters. "Germany came close to the 20 gigawatt (GW) mark a few times in recent weeks. But this was the first time we made it over."