Solar shadows

With the steadily increasing penetration of distributed generation in electric power systems, many in the industry are concerned that our reliable and safe electricity supply might be jeopardised by more decentralised power plants coming online. Indeed, power quality is of crucial importance for the further deployment of renewable generation. The reliability of supply is determined by the number and the duration of power interruptions while the voltage quality is affected by distortions in the waveform. These are deviations from the ideal sinusoidal voltage curve, such as voltage fluctuations, voltage dips, harmonics, flicker and transients, as well as asymmetry and frequency. In most European countries, the power quality specifications and tolerances are laid down in the European standard EN 50160: voltage characteristics of electricity supplied by public distribution systems.