Rennes Métropole has inaugurated its new bus depot at Baud-Chardonnet, which brings maintenance, network control and electric charging together on one site. The building is connected to a wood-fired district heating network and produces part of its own electricity from rooftop solar panels. Moving the depot also frees the former site for new housing in the Baud-Chardonnet district.
What the depot contains
The depot includes a driver service room, a maintenance workshop, the safety and security command post (PC2S) for the whole network, and the centralised control post (PCC) for the bus network and the future Trambus lines. It also has parking for buses and service vehicles, charging infrastructure, a service station, a washing area and support functions. The maintenance workshop, the main building, covers a footprint of 6,400 m².
Energy and solar power
The building uses bio-based materials and is connected to the Rennes Nord-Est district heating network, which runs on wood energy. Solar panels covering 1,366 m² on the workshop roof produce 300 MWh a year, 80% of which is consumed on site. From 2029, Rennes Métropole plans to add more solar installations at both of its bus depots:
| Depot | Canopies | Trackers |
|---|---|---|
| Baud-Chardonnet | 1,200 m² over 6 rows of buses | 23 trackers, 2,565 m² |
| Saint Jacques Mivoie | 1,135 m² over staff parking | 15 trackers, 1,674 m² |
In total, about 6,500 m² of panels are to be installed by 2031, with expected output of 2.4 GWh fed into a grid dedicated to the metropolis’s transport assets.
Cost and reasons
At the end of 2019, Rennes Métropole decided to relocate the previous depot, including its demolition and decontamination, at a cost of over 40 million euros including tax. Charging infrastructure is a separate electrification operation of around 10 million euros including tax. Keeping the depot in the city centre, next to the east-west axis, is meant to control operating costs for the STAR bus network. The old site is released for further housing, notably along the Vilaine.
The wider electrification plan
The depot is part of the STAR network’s energy transition decided in November 2015, which aims to move urban bus lines to electric power by 2032. In autumn 2020, the metropolis approved the purchase of 92 electric Mercedes-Benz eCitaro buses, and nine lines switched to electric between 2023 and 2026. The first phase cost around 80 million euros excluding tax, including 60.6 million for vehicles. A second phase from 2027 to 2032 will accompany the Trambus project.