Deutsche Welle has an article that asks What happens with German renewables in the dead of winter?
I note that the article avoids including graphics from Agora-Energiewende that illustrate the folly of the Energiewende; but DW includes the absurd declaration that Germany just needs more “storage”; apparently from somebody who cannot or who will not do the arithmetic.
So here’s the chart which illustrates that the installed capacity (of more than 80 GW on paper) of wind and solar power in Germany has been unable to meet demand since the start of December. This is of course not news to those who read the article Mind the Gap.
The article further fails to explain that Germany exports electrical power that is a surplus because of the spinning reserve required to maintain a somewhat-reliable supply grid that’s disrupted by wild fluctuations of wind and solar power; the disrupters having priority of supply.
Germany’s “oversupply” would evaporate if its nuclear fleet were being shut down without replacement. But replacements, in the form of new coal-burning power stations, are already under construction and planned. Those, in combination with the older power stations maintained on the grid to maintain the 100% spinning, conventional reserve, required for wind and solar; could mean that Germany will by 2025; exceed its 1990 CO2 emissions. A significant amount of those emissions required just to keep the reserves spinning in case the wind dies down or the clouds move over the country.
Germany’s prime locations for wind power generation have been exhausted. They’re currently devastating protected landscapes and on the fringes of parks to build out more wind power; but even a doubling of it seems implausible; especially given Germany’s population density. It would take around a 5-fold development of wind power to provide the energy necessary to fill the gaps between “renewable” supply and actual demand.
Here’s an illustration of the renewables shortfall in 2016. You can eye-ball the magnitude of the gaping chasm between what wind and solar delivered; and the actual demand for electrical power.
Will German taxpayers and electrical power consumers pay 5 times as much for electrical power and cheerfully endure restless lives in veritable industrial parks of wind turbines? Just to feel that they’re doing something good for the environment? That’ll take a lot of psychotropic medication.
Agora-EW supply figures of total electrical power consumption for 2015 in their summary report.
Around 600 TWh of electrical power was consumed in 2015; 426 TWh came from conventional generation (excluding hydro) and 119 TWh from Wind+Solar, wind doing the heavy lifting with 80 TWh of that. Nuclear power alone provided 92 TWh of the conventional share; greater than the share of wind power.
Thus, to replace just the nuclear share; it would take well over a doubling of installed wind power. That is without considering the intermittency and unpredictability of wind. Intermittency that would need to be compensated by either adding more spinning reserve; or by increasing storage.
Vast over-capacity would have to be installed in order to pump up storage so that sufficient power can be generated when there’s a lack of wind, sun or of both.
Hydro storage is the most-feasible but the required size makes it impractical (and socially unacceptable) in Germany. Hydropower after all delivered just 20 TWh of electrical power in 2015. Storage requirements would span months so around a third of annual consumption has to be allowed for; i.e. 200 TWh or ten times existing hydro-electric resources.
That estimate is without taking into account ecological and actual hydrological considerations including the source and sink basin requirements for the pumped quantities.
Keeping out the Cold
Protagonists of renewables frequently and conveniently overlook that countries like Germany consume vast amounts of energy just to keep warm. Not wind; not PV solar and not hydropower deliver the heat that stop Germans freezing to death in the colder months of the year. Indeed, heating is required for 8 to 10 months a year, depending on the region and the whim of the weather.
Residents of towns and cities benefit(ted) from district heating where a local thermal (hydro-carbon or isotope fuelled) power plant disposes of its “waste heat” by pumping it around town; substantially improving overall plant efficiency. It works best in cold weather.