Template-Type: ReDIF-Article 1.0 Author-Name: Juha Teirilä and Robert A. Ritz Title: Strategic Behaviour in a Capacity Market? The New Irish Electricity Market Design Classification-JEL: F0 Volume: Volume 40 Issue: The New Era of Energy Transition Year: 2019 Abstract: The transition to a low-carbon power system requires growing the share of generation from (intermittent) renewables while ensuring security of supply. Policymakers and economists increasingly see a capacity mechanism as a way to deal with this challenge. Yet this raises new concerns about the exercise of market power by large players via the capacity auction. We present a new modelling approach that captures such strategic behaviour together with a set of ex ante empirical estimates for the new Irish electricity market design (I-SEM) - in which a single firm controls 44% of generation capacity (excluding wind). We find significant costs of strategic behaviour, even with new entry: In our baseline scenarios, procurement costs in the capacity auction are around 150-400 million EUR (or 40-100%) above the competitive least-cost solution. From a policy perspective, we also examine how market power can be measured and mitigated through auction design. Handle: RePEc:aen:journl:ej40-si1-Ritz File-URL: http://www.iaee.org/en/publications/ejarticle.aspx?id=3305 File-Format: text/html File-Restriction: Access to full text is restricted to IAEE members and subscribers.