Geography-based transmission network expansion strategies for Andean electrical systems

In many countries of the Global South, transmission network expansion faces unique challenges due to the diversity of available resources and specific geographic conditions. These challenges are particularly evident in regions with complex geographies, such as the Andean region, where elevation differences and irregular topography pose significant obstacles to the development of electricity infrastructure. This study addresses these challenges by applying non-conventional strategies for transmission grid expansion, with a particular emphasis on adapting to the unique geographic features of the Andean region. To illustrate this, a case study called EC-45 bus system is developed using Ecuador as a country representative of the geographic diversity of the Andean region. Furthermore, this work presents a Mixed Integer Linear Programming (MILP) model that prioritizes the repowering and reconfiguration of existing lines over the construction of new lines. The methodology employed evaluates the investment required for the construction of new lines, considering construction costs for three site types (<1000 meters above sea level (m.a.s.l.), ≥1000 m.a.s.l., and combined). Quantitative results show that using non-conventional solution methods can generate savings of up to 30.60% in investment costs compared to the solution provided by the Linear Disjunctive model. This approach offers a way towards more efficient management of resources, especially in countries with complex geographies such as the Andean one.