Hydro power flexibility for powersystems with variable renewableenergy sources: an IEA Task25 collaboration

摘要

Menemenlis10Hydro power is one of the most flexible sources of electricity production. Powersystems with considerable amounts of flexible hydro power potentially offereasier integration of variable generation, e.g., wind and solar. However, thereexist operational constraints to ensure mid-/long-term security of supply whilekeeping river flows and reservoirs levels within permitted limits. In order toproperly assess the effective available hydro power flexibility and its value forstorage, a detailed assessment of hydro power is essential. Due to the inherentuncertainty of the weather-dependent hydrological cycle, regulation constraintson the hydro system, and uncertainty of internal load as well as variable generation(wind and solar), this assessment is complex. Hence, it requires proper modelingof all the underlying interactions between hydro power and the powersystem, with a large share of other variable renewables. A summary of existingexperience of wind integration in hydro-dominated power systems clearly pointsto strict simulation methodologies. Recommendations include requirements fortechno-economic models to correctly assess strategies for hydro power andpumped storage dispatch. These models are based not only on seasonal waterinflow variations but also on variable generation, and all these are in time horizonsfrom very short term up to multiple years, depending on the studied system.Another important recommendation is to include a geographically detaileddescription of hydro power systems, rivers’ flows, and reservoirs as well as gridtopology and congestion.