Clean power supplied almost all of Germanys power demand for the first time on Sunday, marking a milestone for Chancellor Angela Merkels Energiewende policy to boost renewables while phasing out nuclear and fossil fuels.
Solar and wind power peaked at 2 p.m. local time on Sunday, allowing renewables to supply 45.5 gigawatts as demand was 45.8 gigawatts, according to provisional data by Agora Energiewende, a research institute in Berlin. Power prices turned negative during several 15-minute periods yesterday, dropping as low as minus 50 euros ($57) a megawatt-hour, according to data from Epex Spot.
Germanys power supply by hour
Countries around Europe are building increasing amounts of renewable capacity in order to reduce their carbon emissions and boost supply security. Last year Denmarks wind farms supplied 140 percent of demand, while the U.K. had no coal-fired power stations meeting electricity demand for about four hours on May 10 as a result of plant breakdowns.
Events like this highlight that eventually we may need to start curtailing because of market-wide oversupply, said Monne Depraetere, an analyst for Bloomberg New Energy Finance. In the long-run, that may provide a case to build technologies that can manage this oversupply — for example more interconnectors or energy storage.
Renewables were only able to meet demand because of Germanys strong export capability, the analyst said. Even when solar and wind peaked, conventional power plants were still supplying 7.7 gigawatts.
Merkels unprecedented shift to clean energy has squeezed margins at coal and gas plants while driving up costs for consumers in Europes biggest power market. The increased flows of clean energy have also put pressure on the grid to the point that the country is considering excluding certain regions from future onshore wind power auctions if local grids are already struggling to keep up with large volumes of renewable energy supplies.
If Germany was an island, with no export cables, this would be technically impossible because you always need to have some thermal generation running as a back up supply for when the wind or solar drops off, Depraetere said.
Germany consumed 100 percent renewable energy yesterday, but were unlikely to see clean energy supply 100 percent of generation anytime soon, he said.