The production of electricity through wind turbines and solar panels, has the unfortunate negative aspect that there are strong fluctuations during the production phase.
The figures below show the percentage distribution and the absolute amount of electricity generated during the last week of December 2017 for different power plants in Germany. The low share of solar power is apparent and its peak occurs with regularity at midday. The proportion of wind power varies considerably. Electricity generation reached at times almost 90% of total consumption by wind and Sun. It is also striking that during periods of high electricity generation by wind and solar power energy exports increase by up to 30%.
The fluctions in power generation are balanced at the time being, as shown for Germany in the figure below, by an overcapacity in power plants. Though the capacity of reneables (app. 100 GW) could cover the demand, conventional power generation is still kept as back up..
A strange situation! Does this reduce CO2 output?