Wind Energy Integration into the Grid - Capacity Credit

Power plants using renewable fuels (e.g. power production based on biomass) generally allow scheduling of electricity production, as their primary source of energy can be stored and transported. Within an electricity supply system their use can be planned like any gas- or coal power plant. The process of schedule-development in an electricity supply system is called dispatch. Thus the integration of these dispatchable renewable energy plants does not cause significant changes in the system.

In contrast to this, wind turbines or wind parks are non-dispatchable sources of electricity production: Wind velocity and the related amount of electricity generated is only predictable by meteorological methods (with a limited certainty), but of course there is no possibility to influence the availability of the renewable resources. Electricity production by wind turbines is determined by the available wind velocity and the electricity supply system has to adapt to the characteristics of wind energy, in case the potentials of this renewable resource should be used effectively. Efficient integration of wind energy into an existing power system thus requires an advanced management of the conventional power plant. This article focusses on the effects of wind energy integration on the reliability of an electricity supply system. The Capacity Credit is described as way to quantify the reliability of electricity generation by wind turbines.