Operation of small isolated power system with large non-controllable res penetration – system operator’s experience in El Hierro Island

Abstract

The Canary Islands are facing a transition towards renewable energy, in an attempt to build a cleaner and cheaper power system for the coming years. This transition poses a big challenge for the TSO that will face the operation of weak grids, with a large amount of non-controllable generation, in a context of reduced natural inertia. In this context the methodology and operational criteria of El Hierro’s power system, operated by the TSO, are to maximize the amount of renewable energy in a safe way, minimizing the risks associated with the unpredictability of wind-power, and to do so minimizing the electrical power generation cost. This paper shares the REE experience in the operation of a small isolated power system with large non-controllable RES that, as a result, has established a new record in 2018, where the the pumped storage hydro facility named Central Hidroeólica de El Hierro (CHE) covered the complete island’s demand during 18 consecutive days, more than two weeks where the diesel power plant was completely off and the island was therefore 100% renewable.