Energy procurement for large consumers in electricity markets

The paper considers a large consumer that procures its electric energy in an electricity market, involving both pool and bilateral transactions. Additionally, the consumer operates a self-production facility of limited size. In order to minimise its electricity bill, this consumer should determine the amount of energy bought from bilateral contracts, the quantity of energy purchased from the pool, and the amount of energy self-produced. The novel contribution of this paper is to provide a procedure that allows a large consumer to decide optimally its mix of purchases from different electricity sources. The bilateral contract framework used is flexible enough to accommodate many real-world bilateral electricity agreements. A medium-term decision horizon spanning from one to several months is considered. Results from a realistic case study are presented.