Though solar eclipses are traditionally thought of as astronomic events with no real bearing on society, in fact they do manage to influence processes of practical importance by affecting the energy conversion of photovoltaic systems. The main goal of this study is to explore what could have happened to the German power supply and its reliability during the partial solar eclipse on the 20th March 2015. Comparing results of a simulation with an ex post analysis shows that: 1.) the possible effects could be predicted very accurately, 2.) the electrical supply was not threatened during the solar eclipse and would not have been subject to problems, even in a worst-case scenario, 3.) the actual solar power gradients during the eclipse exceeded the maximum solar power gradients during normal operation observed in the past by at least a factor of two, and 4.) grid frequency analysis for the day of the solar eclipse shows that the maximum and minimum frequency values are well within manageable limits.