The demand for high-voltage transmission lines in Brazil is increasingly high. As many power plants, solar and wind farms start their operation, the gap of transmission has become more evident and, for this reason, the government has prioritized the sector in recent years. This has led to many greenfield mega projects for the construction of transmission lines and substations, where new players arise each year and, with them, lack of experience on the part of the owner is a key factor. More than 12 billion USD in investments were announced in 2016 and 2017, totaling almost 80 different projects and over 25,000 kilometers of transmission lines (15,625 mi).

This paper describes the high-voltage transmission line situation in Brazil. It presents the most common complex construction projects, in which EPC lump sum contracts are usually awarded. The major risks associated with this type of project and contract, along with common mistakes made by the enterprises, methodologies applied, or not applied and their consequences are reviewed.