The role of hydroelectric generation in electric power systems with large scale wind generation

Abstract

An increasing awareness of the operational challenges created by intermittent generation of electricity from policy-mandated renewable resources, such as wind and solar, has led to increased scrutiny of the public policies that promote their growth and the regulatory system that maintains operation of a reliable and economically efficient power system. Anecdotal evidence has suggested that hydroelectric generation can provide significant benefits in power systems that have already significantly increased their power generation from intermittent renewable resources. A heuristic-based algorithm for optimizing the scheduling of hydroelectric power generation facilities was developed and integrated into the Low-Emissions Electricity Market Analysis (LEEMA) model to analyze the interaction of generation capacity from wind, thermal, and hydro resources in the economic dispatch of individual generation plants. The algorithm identifies the most costly periods of thermal production, considering fuel, startup and operation and maintenance costs, to determine the optimal schedule of hydro generation within its capacity constraints. The hydrothermal LEEMA model is run on the current Spanish electric power system to identify the impact of introducing hydro generation to a system, varying levels of flexibility in hydro generation, and increasing levels of wind generation. The analysis concludes that hydro generation can significantly reduce the impact of intermittent renewable generation, that the level of flexibility of hydro generation must be understood to determine how beneficial the hydro generation can be, and that hydro generation will delay the most significant impacts of increasing levels of wind generation.