Market efficiency assessment under dual pricing rule for the Turkish wholesale electricity market

Abstract

This study analyses the price dynamics of day-ahead and real-time electricity prices following the implementation of dual-pricing legislation in Turkey, to understand the legislation's impact on arbitrage opportunities and market efficiency. The convergence of prices between the day-ahead forward and the real-time markets analysed in order to determine whether persistent price differences between the two markets exist. Arbitrage opportunities exist if there is a persistent difference between prices in the day-ahead forward and real-time market. Markets are considered to be efficient if it is not possible for market participants to earn an excess profit through exploitation of price differences. Furthermore, we examined how the ex-post risk premium changes over time using rolling estimations and find that after the implementation of dual pricing, the risk premium increased significantly for day and peak hours where the demand is relatively higher compared to night hours. As market participants have more experience regarding the dynamics of the market, the difference between real-time and day-ahead forward prices converges to zero since the dual-pricing regime enforce market participants to forecast accurately by punishing the forecast error.