Regional diversification of hydro, wind, and solar generation potential: A mean-variance model to stabilize power fluctuations in the Brazilian integrated electrical energy transmission and distribution system

This study aims to investigate the heterogeneity and complementarity of the regional potential for generating hydro, wind, and solar energy to smooth generation variability. A bi-objective mean-variance model is proposed to determine hydro, wind, and solar-generation portfolios that simultaneously maximize interregional average generation and minimize system generation variability, thus increasing the reliability of the system and diversifying energy generation. These portfolios form the so-called efficient frontier, which shows all combinations of hydro, wind, and solar energies that produce the lowest variation for any level of energy generation. The findings demonstrate that, in Brazil, the current regional wind energy generation portfolio is close to the efficient frontier with high variability, the current centralized solar energy generation portfolio is far from the efficient frontier, and the current hydropower power generation portfolio is situated on the efficient frontier with low variability.