Handling balancing power in a power market with a large share of hydropower

This paper presents a model well suited for analysis of power systems with a large share of new renewable in combination with hydropower and pumped-storage hydro. The model is designed for a detailed hydropower representation and can be used with hourly time resolution. The model solves the detailed dispatch of hydropower in two steps. First it uses a heuristic model for weekly decisions where the goal is to find the target for end reservoir levels. Then the problem is re-solved as a formal optimization problem where the goal is to fully utilize the flexibility in the hydropower system within the week. The new model is based on EFI´s Multi-area Power Market Simulator (EMPS) model which is designed for long- and medium term scheduling. The new model is an enhancement to the simulation part of the EMPS. A simple test case is presented to illustrate the use of the model in a hydropower dominated system. The test case has a significant amount of wind power and available pumping capacity can be used as balancing power.