Modeling and Planning of the Electricity Energy System with a High Share of Renewable Supply for Portugal

Abstract The electrical supply system of Mainland Portugal is primarily responsible for 25% of the country’s CO2 emissions. The principal reason for these high CO2 emissions is the significant dependence on coal power plants, which account for approximately 30% of the overall electricity generation. In 2018, to ensure CO2 emissions reduction, the Portuguese Government presented the “National Renewable Energy Action Plan for 2030”, a strategic proposal for the sustainable development of the Portuguese economy through the decommissioning of fossil power plants. This study presents, on the Portuguese mainland scale, electricity system technical solutions for achieving CO2 emissions reduction, using the guidelines of the Portuguese Government plans for the upcoming decades, and a high share of renewable energy supply. The technical solutions were achieved using an hourly electricity balance via the EnergyPLAN software. The study also identifies the minimal load capacity value of thermal power plants required to maintain the security levels of the Portuguese electrical system and highlights the importance of pumping hydropower plants for the integration of variable renewable electricity sources.