The project involves the energy retrofit of the EL-TO power plant, which provides electricity and district heating to the city of Zagreb. To bring the plant up to current environmental standards, a new combined cycle gas turbine (CCGT) cogeneration plant has been installed.

The power plant is equipped with the Rainplus siphonic drainage system, with the installation of 29 manholes. It was a significant technical challenge due to the metal structure and the positioning of the manholes at a height of 30-40 meters: the support of partners CEV Instalacije d.o.o. and MANS d.o.o. was crucial.