Electricity generation from wind and sun is often criticized as somehow being unreliable. There is even an insult for this in the German political vocabulary: "Flatterstrom!" This is often put in contrast with the presumed reliability and stability of good old baseload power plants like coal or nuclear. These tend to produce largely the same amount of electricity day in day out - as long as they don't have to be shut down for maintainance or due to adverse weather conditions . Given that electricity demand is variable, how useful is constant production when the goal is for production to match load at all times? And how much worse would "Flatterstrom" be in comparison? Using again the thought experiment from this previous post , we consider the current hourly load over a year for Europe's two largest electricity markets, France and Germany. Then we assume two generation profiles which in total matches exactly the total yearly: a fixed, constant production
In this previous post , we looked at how much of the current electricity demand could be met directly if the entire production were based on solar and wind. The observation was that depending on the country, about 70-80% could be covered in real-time by scaling up an optimal mix based on the current solar & wind generation capacity. This would leave about 20-30% of unmatched load at some times and the same amount of surplus at other times. In this post , we looked at how storage and in particular under-utilized car batteries could be used to help balance the grid between times of over and under-production. Another potential approach of increasing the balance between supply and demand would be to improve geographic diversity across wind or solar generation beyond the synoptic scale of common weather pattern which is in the order of a thousand or more kilometers. The image above shows the site of the Laufenburg substation , where in 1958 the national grids of France, Germany and Sw