In the last post, I gave some basic numbers for the status of the transition to renewable sources of electricity in Europe, circa 2012. But what does that look like, in terms of actual month-to-month, day-to-day and hour-to-hour function of Germany’s electricity system?
Fortunately, the folks over at Fraunhofer Institute for Solar Energy Systems (ISE) have provided us with detailed charts, in English, with data from the EEX Transparency Platform. A sample from page 59 is shown below:
This document clearly shows how solar has effectively met most of Germany’s daytime peak load during most months of the year, and how wind has complemented solar in the winter. Contrary to the claims of nuke and fossil fuel apologists, the sky has not fallen, and the grid is actually meeting demand better (and cheaper) with wind and solar.
It is true that the sun does not shine all the time, nor does the wind blow. Despite the generally complementary nature of wind and solar, on a rare occasion neither is producing strongly. Fortunately, we have something called “flexible generation”, which means that output from other energy sources (mostly natural gas, sometimes coal and even nuclear) have been turned up and down to accommodate for shifts in demand.
What fossil and nuke apologists don’t tell you is that this is a central feature of how electricity grids work, and that such resources were shifted due to hour-to-hour and day-to-day demand changes before renewables were introduced. Another revealing feature of EEX data is that the need for deployment of flexible generation is much lower in Germany with solar and wind than without it.
It is true that there are limits to flexibility. Fortunately, we also have another novel 20th century idea: “international electricity markets”. This means that Germany is selling its excess electricity from wind and solar to other nations, and importing electricity when it needs it.
Eventually, in order to power a national grid or continent-wide grid entirely on renewables, we will need additional storage. That is also not an insolvable problem, and some of the best minds in the industry are working on lowering the cost of energy storage.
In the mean time, flexible generation and electricity markets are working just fine in Germany, Denmark, and other nations with high percentages of renewables. The only “problem” is with the profits of fossil fuel and nuclear companies, and the threat to their business models and future.
Which is a good thing for all of the rest of us, and our children.