Begun in June 2023 and completed in April 2024, construction of the Serra do Assuruá wind power complex in Gentio do Ouro, Brazil, is a project on an exceptional scale. The aim of this project in the Gentio do Ouro municipality, 600 km from the Bahia state capital, is to address the increase in local energy production flows and the expansion of regional interconnectors. 

Implemented by the Engie group in partnership with Omexom Transmission Lines Brazil, this remarkable project involved the construction of a 230 kV transmission line more than 28 km long and with a capacity of 846 MW, markedly higher than the 400 MW average for this type of line.  

The project featured notable technical and logistical challenges, innovative technological choices and strong CSR commitments. The Omexom team faced a series of challenges, including the selection and installation of materials, appropriate sizing of structures and effective management of resources, while dealing with the unique features of this terrain rich in mineral ores. Special geological studies were needed to design the earth connection system, and a particularly long rainy season posed additional challenges. 

“During the budget planning phase of the project, we realised that no 500 kV connection would be available at one of the two substations involved – namely, Gentio do Ouro II,” explains Henrique Santos, Project Engineer at Omexom Transmission Lines Brazil. “We carried out a study to determine the number of cables per phase and the gauge required, using transient electromagnetics.” To resolve the issue, “We installed four cables per phase, but opted for a single rather than double circuit, which was more economical in terms of the amounts of steel and concrete required for the tower structures and foundations. The latter have to be stronger to support the four cables used per phase. In total, we installed more than 395 km of cables.” 

Another notable feature of this project was how the Omexom teams made use of local resources, sourcing goods and services from the surrounding area to meet most of their needs (accommodation, food, internet, water, energy and civil engineering materials). Only the largest supply orders, for example the metal structures, conductor cables and insulation, were purchased from non-local suppliers, due to their complexity.