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Abstract:The increasing share of renewable energy sources, such as wind and solar generation, has a direct impact on the planning and operation of power systems. In addition, the consideration of risk criteria within the decision support tools used by market participants (generation companies, energy services companies, and arbitrageurs) is becoming a common activity given the increasing level of uncertainties faced by them. As a consequence, the behavior of market participants is affected by their level of risk aversion, and the application of equilibrium-based models is a common technique used in order to simulate their behavior. This paper presents a multi-stage market equilibrium model of risk-averse agents in order to analyze up to what extent the operation of hydro reservoirs can be affected by the risk-averse profile of market participants in a context of renewable energy source penetration and fuel price volatility.

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Intermittent electricity generation of the various renewable energy sources sets additional burden on generation unit dispatching and reserve planning in day-ahead electricity market. The conventional unit commitment models which include rump-up and rump-down limits are usually presented with stepwise mathematical functions without clear distinction between power and energy. This paper presents a case study of generation unit dispatching planning approach for the case of pricewise-linear functions from one time interval to another, taking into account actual ramping trajectories thus providing more efficient reserve scheduling particularly during generators’ start-up and shut-down processes. For the representation of reserve schedules, the 10-min and 30-min ramp capabilities of the generation units are assumed where they are obliged to provide secondary, tertiary and offline-tertiary reserves depending on their technical capabilities. The Serbian power system case study represents a 24-hour unit commitment planning and up/down secondary and tertiary reserve requirements during a scarcity event when reserve flexibility of neighbouring power systems cannot be utilised. Formulation of the optimisation mathematical model is performed via GAMS, the General Algebraic Modelling System, and CPLEX optimiser is used for problem optimisation purposes.