Abstract

By 2022, Chile had developed substantial solar photovoltaic (PV) and wind capacities, with installations of 4,200 MW and 3,111 MW respectively, which together constitute over 30% of the nation's total installed capacity [1]. From 2015 to 2017, there were notable periods where the marginal cost of electricity fell to 0 USD/MWh, primarily due to NCRE overproduction coupled with low demand. Since 2016 and present extensive periods of zero-cost solar energy for up to 113 days [2][3][4], a phenomenon spurred by the copper sector's boom and overall economic growth. This led to an energy surplus, particularly in the north, exacerbated by a disconnect between northern production areas and central demand zones. Initially, the national grid was split into the Great North Interconnected System (SING) and the Central Interconnected System (SIC), with no interconnections until 2018, presenting significant operational and financial challenges. In response to these grid integration issues, the Chilean government initiated major projects in 2016 to integrate these systems, culminating in the completion of the Cardones-Polpaico transmission line in 2019. This crucial infrastructure development not only unified the SING and SIC into the new National Electric System (SEN) but also enhanced grid stability, reduced energy costs, and increased market competitiveness. The successful integration demonstrated its effectiveness by swiftly reaching full operational capacity, facilitating smoother energy transitions, and fostering international interconnections. Building on this backdrop of energy surplus and grid integration challenges, this paper presents a comprehensive techno-economic analysis of a utility-scale Concentrated Solar Power (CSP) system with Thermal Energy Storage (TES), based around a Solar Power Tower (SPT) equipped with 18 hours of storage. Through simulating daily dispatch scenarios, the study explores strategies for optimizing energy storage and dispatch based on real-time market prices. It specifically examines how the CSP system can capitalize on periods of zero or low energy prices for charging and then dispatch stored energy during peak pricing periods at night. Augmented by a genetic algorithm, this strategy aims to optimize dispatch strategies to bolster economic returns and align with market fluctuations, thereby demonstrating the capacity of renewable energy systems to not only advance energy sustainability but also to attract investment by improving grid reliability and resolving issues with curtailments in Chile. This approach underscores the commitment to enhancing the attractiveness of the Chilean renewable energy sector to investors, seeking to mitigate the challenges associated with an intermittent energy supply.