Competition between NCRE, Batteries and Flexible Thermal Units in the Planning of Generation Expansion in Uruguay

It is analyzed from a Simple Energy Model how Non-Conventional Renewable Energies (NCRE) reduce generation costs in a hydrothermal system by replacing thermal generation based on fossil fuels. When examining the seasonal and hourly correlation of demand with wind and solar generation in Uruguay, it is concluded that, for the same cost, wind energy is the one that would best contribute energetically to the Generation Expansion Planning (GEP) due to its good correlation with seasonal demand. On the other hand, solar energy would stand out in its daily ability to complement itself with storage (hydraulic or batteries), competing with flexible thermal backup. Finally, in the context of a specific GEP study in Uruguay, these conclusions are confirmed and it is shown how the duration of storage in battery banks, the Fault Cost value, and the compliance with specific Loss of Load Probability (LOLP) metrics influence and interact in the GEP.