Decarbonized Market Design: An Insurance Overlay on Energy-Only Electricity Markets
In the face of challenges to energy-only market design under the electricity sector transition, an option considered by many jurisdictions is to incorporate some form of centralized capacity mechanism to respond to shortfalls in the market provision. For example, the UK government has already introduced a formal capacity market. In Germany and Belgium, strategic reserve mechanisms have already been approved and will be introduced shortly. Other markets, such as the National Electricity Market of Australia, are also considering enhancing their existing strategic reserve mechanisms, which would see more standardized and continual procurement of capacity by a noncommercial central agency. Under a market transition where generation is increasingly stochastic and decentralized, two key issues emerge with the above approaches. First, centralized mechanisms put increased focus on the efficiency of central authority decision making and the alignment between performance outcomes for reliability and agency incentives. Second, existing capacity mechanisms require the central agency to infer consumer preferences for reliability, something that is very challenging in practice. This is especially relevant in markets where the value of lost load is increasingly differentiated among different consumers. In this paper, we propose a new model for electricity market design—the insurer-of-last-resort model—that works as a risk overlay on an existing energy-only market. This model unbundles energy and reliability and incorporates insurance-based risk management concepts with the aims of (1) aligning incentives for centralized decision making and (2) allowing revealed consumer preferences to guide new capacity deployment.