Market-Clearing Electricity Prices and Energy Uplift

Abstract

Electricity market models require energy prices for balancing, spot and short-term forward transactions. For the simplest version of the core economic dispatch problem, the formulation produces a well-defined solution to the energy pricing problem in the usual form of the intersection of the supply marginal cost curve and the demand bids. In the more general economic unit commitment and dispatch models, there may be no analogous energy price vector that is consistent with and supports the quantities in the economic dispatch solution. Uplift or make-whole payments arise in this condition. Comparison of three alternative pricing models illustrates different ways to define and calculate uniform energy prices and the associated impacts on the energy uplift required to support the least cost unit commitment and dispatch.