International comparison of wind and solar curtailment ratio

As the penetration of VRE (variable renewable energy), mainly wind and photovoltaic energy, has developed widely and rapidly, curtailment of VRE has taken on increased interest. This paper introduces a new evaluation tool, named the "C-P map", that shows the correlation between VRE curtailment ratios and energy penetration ratios of VRE in selected countries/areas. The C-P map can illustrate historical trends for VRE curtailment ratios in a given country/area at a glance, and help any comparison between historical curves. Using the C-P map, this paper classifies the selected countries/areas into several categories, depending upon the level and trends of VRE curtailment. The classification helps to understand how curtailment occurred in the past and how it may change in the future in the selected grids.