An experimental study of capacity remuneration mechanisms in the electricity industry

Céline Jullien, Haikel Khalfallah, Virginie Pignon, Stéphane Robin and Carine Staropoli

Abstract

After electricity liberalization, the “energy-only market” design lacks effective incentives to invest in new capacity. Across the world, capacity remuneration mechanisms have been taking hold as an alternative to the energy-only market to ensure adequate power generation capacity. The way these designs are characterized reflects the insight from general economic theory on market power and strategic behavior. Indeed, Europe is heading toward a patchwork of different, uncoordinated national mechanisms. In practice, design choices are driven by national policies, needs and constraints. In addition, they are progressively converging toward a market-based mechanism with a forward period and market power mitigation. In this paper, we investigate their efficiency properties in terms of new investments, the reduction in unserved energy frequency and the energy prices of a generic capacity remuneration mechanism that is impervious to the so-called forward capacity market. The results from laboratory experiments confirm that this mechanism gives better incentives to invest in new capacity than the energy-only market alone and provides an empirical understanding of the investment decision process. The forward capacity market contributes to lower energy market prices in peak demand and extra-high peak demand periods and average energy costs if we consider the social cost of unserved energy.