Sustainable island power system - Scenario analysis for Crete under the energy trilemma index

Sustainable energy supply is an essential part for economic and social development in every society. Islands as geographical isolated regions have to confront a number of challenges to secure a reliable and clean energy system. Currently, electricity demand on the Greek island of Crete is supplied by oil-fired engines imposed to new emissions restrictions applied from 2020. Thus, a capacity upgrade is necessary and new solutions driven by renewable energy, energy storage and interconnections. This study investigates three scenarios: Business as Usual (BAU); Natural Gas (NG); and the Interconnection of Crete with the National Grid System (Int.) to assess the potential techno-economic and environmental impact of the required transition under the Energy Trilemma Index. A capacity expansion and operation optimisation process has been applied through a high resolution spatio-temporal analysis performed with PLEXOS Integrated Energy Model. It was concluded that no BAU Scenario could facilitate a future plan for the electricity system of Crete or any European island imposed to such constrains. The optimum scenario incorporates interconnectors and energy storage systems that manage to deliver 52% reduction in the total system costs (2020-2040), 79% in electricity generation costs and 48% reduction in GHG emissions by 2040, compared to the BAU.