The Community of Madrid is carrying out the transformation of the electrification system of Metro Line 6 with the goal of preparing it for the circulation of driverless trains. This action is part of the project to fully automate the Circular Line, which in 2027 will become the first line in the network with automatic driving. 

Specifically, during the initial phase of the works undertaken on the western section between June and September, the voltage of the catenary has been increased from 600 to 1,500 volts. This has required the comprehensive refurbishment of seven electrical substations, Moncloa, Puerta del Ángel, Lucero, Carpetana, Plaza Elíptica, Usera and Arganzuela. 

In these facilities, the old parts have been disconnected and dismantled, and new protection and control systems have been incorporated, as well as transformers and rectifiers adapted to the new voltage required for future automation. 

This change will also enable greater energy efficiency after the comprehensive reopening of L6, reducing, according to initial studies, up to 30% of electricity consumption on this line and 3.6% across the entire Metro network. 

The extremely complex work represents a new technical achievement in the history of the Madrid underground, as it has been carried out without completely interrupting service on the line. Careful planning has ensured the correct demand for electricity on the grid at all times, which has made it possible to avoid incidents in the facilities. This operation will be repeated at all the necessary substations during the execution of the work on the eastern arc. This action is co-financed at 40% under the 2021–2027 ERDF Programme of the Community of Madrid.