Karalis 220 kV Grid Connection Substation

The Karalis project is a benchmark for the efficient integration of renewable energy into the National Transmission Grid, delivered under a turnkey EPC contract. The principal challenge was to coordinate, within a single contract, the construction of a shared 150 kV electrical substation serving multiple renewable energy producers, the installation of a power transformation system, and the connection to the National Transmission Grid.

SELT managed the entire delivery process in-house, from earthworks and construction of the control building to the transportation and installation of a 250 MVA autotransformer. The project was completed with the construction of a 220 kV underground transmission line built in accordance with Terna’s technical standards, including specialist cable jointing and terminations.
A key strength of the project lies in its operational flexibility. SELT delivered a complete infrastructure designed to accommodate future network developments, demonstrating how integrated EPC delivery can simplify the connection of large-scale renewable energy projects to the National Transmission Grid.