Equilibrium values in competitive electricity markets.

Abstract

We consider non-sealed and sealed bid electricity markets with demand uncertainty. In such markets, each generator decides on a bidding price to maximize its profit. In a non-sealed bid market, bids are disclosed to the public while they are kept undisclosed in a sealed-bid market. Generating units are dispatched in the ascending order of their bids until demand is satisfied. The market clearing price is the highest bid among the dispatched units. All dispatched units are then sold at this market clearing price. Both stochastic and deterministic versions of the electricity demand are considered. We focus on markets with identical bidders, same cost bidders, and bidders with different generating costs. Assuming that the bidders are rational, we derive the characteristics of the bids in these markets as well as the resulting market clearing prices. In addition, algorithms and numerical methods are developed for finding the equilibrium points. In all of our analysis, a market stability condition is assumed as a requirement for the market to be operable. This condition can also be used to determine the redundant bidders in the market and, hence, reduce the size of the problem.