Hydro power flexibility for powerrnsystems with variable renewablernenergy sources: an IEA Taskrn25 collaboration

摘要

Menemenlis10rnHydro power is one of the most flexible sources of electricity production. Powerrnsystems with considerable amounts of flexible hydro power potentially offerrneasier integration of variable generation, e.g., wind and solar. However, therernexist operational constraints to ensure mid-/long-term security of supply whilernkeeping river flows and reservoirs levels within permitted limits. In order tornproperly assess the effective available hydro power flexibility and its value forrnstorage, a detailed assessment of hydro power is essential. Due to the inherentrnuncertainty of the weather-dependent hydrological cycle, regulation constraintsrnon the hydro system, and uncertainty of internal load as well as variable generationrn(wind and solar), this assessment is complex. Hence, it requires proper modelingrnof all the underlying interactions between hydro power and the powerrnsystem, with a large share of other variable renewables. A summary of existingrnexperience of wind integration in hydro-dominated power systems clearly pointsrnto strict simulation methodologies. Recommendations include requirements forrntechno-economic models to correctly assess strategies for hydro power andrnpumped storage dispatch. These models are based not only on seasonal waterrninflow variations but also on variable generation, and all these are in time horizonsrnfrom very short term up to multiple years, depending on the studied system.rnAnother important recommendation is to include a geographically detailedrndescription of hydro power systems, rivers’ flows, and reservoirs as well as gridrntopology and congestion.