June 24, 2014
On May 11, electric power demand was modest in Germany, even for a Sunday. Comfortable weather meant minimal use of heating and air conditioning — the day saw highs around 14°C (57°F) and lows around 10°C (50°F). Power demand peaked at 55 gigawatts at midday, compared to 65 GW on Friday, May9.
Midday power production by wind turbines averaged 20 GW, about 36 percent of demand. Photovoltaic (PV) production reached 17 GW, about 31 percent of demand. Together with hydro power and biomass, renewables provided roughly 74 percent of power consumed between noon and 2:00 p.m. The episode put electricity prices in a tailspin. The day-ahead price for peak power went negative: generators paid 1.7 cents per kilowatt-hour to offload excess power.
It wasn’t even the biggest production day for solar in May. That fell on May 5, when German PV peaked at 22 GW. Renewables accounted for 27 percent of all German electricity generation in the first quarter of 2014.