Can the European intraday market be designed as a congestion management tool?

Abstract

The growth in intermittent renewable power in Europe has increased the need to trade closer to real-time. In recent years, intraday markets have been integrated across Europe, contributing to a more efficient market. On the other hand, European day-ahead and intraday markets are still based on zonal pricing, where the physical characteristics of transmission networks are only partly taken into account, and congestion problems may remain until close to real-time. In this paper, we suggest an intraday market design based on the coordinated multilateral trade (CMT) approach, using power transfer distribution factors and other network information provided by the transmission system operators, to generate profitable, but feasible, and possibly multilateral trades based on nodal bids. Profitable trades can be found by independent brokers or by having the power exchange running frequent batch auctions at discrete-time intervals. Each trade is accepted by the TSO if no violation occurs in the network, or is curtailed. If the network flow is feasible at the start of the intraday market, the procedure converges to the optimal economic dispatch. In any case, this suggestion for intraday trading, taking into account simple information about network constraints, in a procedure consistent with the functioning of the European intraday market, can help bridge the gap between the zonal day-ahead markets and the real-time constraints of the power system.