Generation scheduling in island systems with variable renewable energy sources: A literature review

Abstract

Non-interconnected island systems around the globe present a great variety and substantial particularities regarding the methods applied in generation scheduling, primarily under high renewable energy sources penetration levels. Under such conditions, one of the main challenges in island systems is the coherent treatment of intermittent renewable generation and the implementation of robust unit commitment and economic dispatch methodologies, seeking to achieve high RES absorption rates, least cost scheduling, and system security. In this paper, an extensive and in-depth literature review is undertaken to identify the generation scheduling principles and methods applied in island systems experiencing high renewable penetrations. Principal features of electricity markets in islands are highlighted, state-of-the-art unit commitment and economic dispatch models suitable for such applications are identified, and their advantages and limitations are discussed. The effect of renewables uncertainty on the islands’ scheduling is analyzed, especially regarding the classification and quantification of system operating reserves to enhance operational security and system stability. Given the isolated nature and limited inertia of islands, very high RES penetration targets may impact their ability to survive severe contingencies, a topic also addressed in this paper, extending the review to include literature on frequency-related dynamic phenomena for isolated systems.