Security of supply during the energy transition: The role of capacity mechanisms

The push for clean energy has caused a rapid growth of renewables in the electricity supply mix of the EU. Although one would assume that the impact of these technologies is entirely positive, recent research and experience indicate that there is reason for concern namely regarding the security of supply. In this context, the concern is how renewable energy sources (RES) affect the business case of conventional power generation. In response to this concern, capacity mechanisms are being considered or have already been implemented by various member states of the EU. However, in a highly interconnected electricity system, such as the one in Europe, there appears to be a risk that the uncoordinated implementation of capacity mechanisms may cause unintended cross-border effects. This research explored the performance of various capacity mechanisms in an electricity system with a strong growth in the portfolio share of variable renewable energy sources (RES). The cross-border effects of implementing various capacity mechanisms in an interconnected power system were also analyzed. In this research, two capacity mechanisms, namely a strategic reserve and a capacity market, were modeled as extensions to the EMLab-Generation agent-based model. Furthermore, two variations of a capacity market were analyzed. The first was a yearly capacity market design and the second was a forward capacity market with long term contracts. A survey of experts on the US capacity markets supplemented the modeling work with practical insights