Incorporating the climate-water-energy nexus in the brazilian power generation expansion planning model through multi-objective optimization

Abstract

This work tackles the problem of inserting the Climate-water-energy nexus in the decision making of the optimization model officially adopted for planning long term electricity generation expansion in Brazil. The model, which is called the Investment Decision Model, originally has a formulation that minimizes the total cost of expanding the sector based on technical and financial parameters, requiring the inclusion of the environmental aspect. In this sense, the formulation was modified in order to carry out a multi-objective optimization that also seeks to minimize total carbon emissions and water consumption in the life cycle of several electricity generation sources. From the two multi-objective optimization approaches adopted, it was possible to verify how all defined objectives are connected. The results show that, in general, there is an increase in the expansion of renewable sources, mainly wind, solar and thermal biomass, depending on the adopted premises for the created instances. They also demonstrate an elevation in the total expansion cost as well as a reduction in greenhouse gases emissions and in the volumes of consumed water due to the fact that the sources with better environmental performance are more expensive. Finally, it is concluded that it is possible to generate an investment schedule that analyzes both aspects and, hence, balances the rise in financial expenses with the decrease in the analyzed environmental impacts.