German power producer EnBW has sent a letter (see below) to its customers informing them that the situation was under control as tomorrow’s solar eclipse is poised to put Germany in partial darkness shortly before noon and to test the country’s power grid stability.
Because of the eclipse, up to 12,000 megewatts of PV power could disappear from the grid (if it’s sunny) in a mere hour at around 10:00 a.m. Then, shortly before noon, 19,000 megawatts could surge into the power grid in just an hour as the moon allows the sun’s radiation to shine back in unhindered.
EnBW warns of possible grid instability and the disruption of frequency sensitive industrial machinery as a result. In Germany power generators themselves are not allowed to operate power grids. Independent grid operating companies perform that task.
EIKE writes that the letter seems to pre-emptively point the finger at the grid operators should blackouts or disruptions occur.
What follows is that letter, translated in English (German version thanks to J. Kowatsch):
Re: Partial solar eclipse on March 20, 2015:
Your power supply is in good hands
Dear Ladies and Gentlemen
On March 20, 2015, a partial solar eclipse will occur over parts of Europe. This natural phenomenon will also have impacts on the power supply. As your partner for all matters concerning energy, we have put together a few important facts.
The solar eclipse will begin in Spain and end in Scandinavia. In Germany between ca. 9:10 and 12:00 noon up to 82% of the sun will be covered by the moon. If the sky is overcast, then the possible impacts will be very limited. However on a sunny day it will lead to a drop in power generation from PV systems of up to 12,000 megawatts in Germany, which is equivalent to 12 large power plants. Beginning at about 10:50 the power will then increase by up to 19,000 megawatts within about an hour.
The four power transmission grid operators in Germany are responsible for ensuring the usual system stability. The challenge is to completely balance the drop and the later subsequent rapid increase in power fed in from the PV systems by using many flexible power generations units. The power transmission grid operators have prepared well for this event. The employees at the grid control and switching centers have been trained for this special situation, and control centers will be manned with extra personnel on March 20, 2015.
Yet the chances of disruptions cannot be fully excluded. For example frequency fluctuations can effect sensitive systems (CNC machines, robots and other computer-controlled systems, etc.). Should you have any concerns, we recommend that you drive your systems down to a stable condition.
You will find more information at a mutual press release by the four power transmission grid operators dated 23 February, 2015, which we have enclosed. Moreover you will find at “Zeit online“ a fuctuial article as well as a video animation [scroll down] which illustrates very nicely the possible impacts on power feed-in by PV systems in Germany on a sunny day: http://blog.zeit.de/gruenegeschaefte/2015/03/03/sonnenfinsternis-energiewende/.
Have you got questions? Then give me a call. I’m gladly at your service.
Sales & Solutions GmbH
i.V. Christoph Schade
Enclosed: Press release by the four power transmission grid operators from February 23.