The project includes two main supplies: on trolleybuses and electric buses:1. Delivery of 30 new low-floor articulated trolleybuses that will replace depreciated vehicles. In order to ensure their normal operation, the reconstruction and modernisation of 3 rectification stations is envisaged. Rectification stations (CRTs) are the main link of the power supply system for the metropolitan electric transport. They convert the three-phase voltage supplied by the electricity distribution company into a DC voltage necessary to power the trolleybuses. In this respect, the efficiency and integrity of the TEC supply lines on which the newly purchased trolleybuses will run is crucial for their normal operation.2. Delivery of 30 new electric buses and 10 new charging stations. To ensure the normal operation of the new rolling stock, new complete transformer stations are planned. The project provides for the construction of electric bus lines to replace existing bus routes. Electric buses will use state-of-the-art fast-charging technologies based on ultracapacitors. 10 charging stations will be built for their charging, located at the initial and final stops and in service depots. In connection with the supply of charging stations from the catenary of Sofia Electrical Transport EAD, it is necessary to build new KTPs (complete transformer stations) at selected locations.