A Novel Procedure to Forecast Annual RES Curtailments in the Spanish Power System

Abstract

Renewable energy sources (RES) curtailment occurs when the injection from RES exceeds the grid's capacity to absorb it either because it surpasses the demand to be delivered, or because it creates technical constraints. Currently, RES curtailment in continental Spain occurs when RES generation causes overloads incompatible with Spanish security criteria. Forecasting annual RES spillage for a specific future plant to be located in a certain area of the Spanish power system becomes critical for the promoter in order to decide the size and confirm the investment profitability. This paper proposes a novel procedure to forecast annual RES curtailments of a future plant to be deployed at a certain location of the Spanish peninsular real-life power system where real-life limited information is available. The procedure comprises three steps: (a) selection of a most critical reference scenario representative of both high demand and RES production, (b) detection and solution of overloads with minimum RES curtailment, and (c) intersection of computed maximum RES injection with load-duration curve. The computation of the short-term annual energy spillage of a future 300 MW solar photovoltaic (PV) power plant to be deployed in Aragon autonomous region (northeast of Spain) is provided as case study to illustrate the simplicity and adequacy of the method.