Abstract
In this paper we compare several methods used by hydropower producers for the determination of bids to the day-ahead market. The methods currently used by the hydropower industry are based on heuristics and expert assessments, but we also include a new method for formal optimization of the bid decisions in our study. The optimization of bids is based on stochastic programming with explicit mathematical representation of the bid decisions, which none of the heuristic methods accommodate. We illustrate the potential benefit from using increasingly complex bidding methods in a case study representing real operating conditions for a hydropower producer on three specific dates