Sustainability is a top priority for public transportation in Angers, France. The city’s entire tram fleet is operated using an eco-friendly ground power supply. Energy-efficient room automation at the tram depot also contributes to reducing the CO₂ footprint: based on the EnOcean technology, smart wireless sensors from Thermokon enable a demand-based control of room temperature, heating, and lighting.
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Energy-efficient automation for RATP
Smart Wireless Sensors from Thermokon for the RATP Tram Depot in Angers, France
Located in western France near the Loire Valley, Angers is known for its numerousparks and gardens. With around 160,000 residents, the city is also rich in culture and history – most notably the 103-metre-long "Apocalypse Tapestry" housed in the Château d’Angers, considered the world’s largest medieval tapestry and registered in UNESCO’s "Memory of the World" programme.
Public transport plays a key role in Angers’ high quality of life. In addition to an extensive bus network, a tram system was launched in 2011, operated by the international RATP Group. The network covers 29 municipalities with a population of approximately 300,000. The brightly coloured trams – often referred to as “rainbow trams” – run on three lines and are powered via ground-level electricity supply, an environmentally friendly method that eliminates air pollution and significantly reduces noise emissions.
Autonomous Control of Room Parameters
The trams are maintained at a central depot in Angers. After nearly 15 years of use, RATP aimed to improve the depot’s energy efficiency and therefore decided to equip both the maintenance hall and all staff areas with smart room sensors. The goal was to enable autonomous, occupancy-based control of heating and lighting, achieving highly energy- and cost-efficient operation.
A representative of the Automation and Industrial IT Systems department at RATP emphasized the advantages of wireless technology:
“We wanted the implementation to be as time- and cost-efficient as possible. The ability to integrate all components into the building management system without extensive wiring work made a wireless solution the ideal choice.” In search of a product portfolio that combined these requirements with high reliability and low maintenance, the team turned to Thermokon. The performance and versatility of the EnOcean-based solutions proved convincing: "The broad range of sensors for different applications allowed us to adapt flexibly to specific requirements. Thermokon also stood out for the high quality and reliability of its solutions – a key factor for precise measurement and control of room parameters.”
Cost-Efficient: Wireless Sensors with Energy Harvesting
Planning and implementation were carried out entirely in-house by RATP, without the involvement of an external system integrator. Thermokon’s solutions were integrated into an SBC building management system through the bidirectional STC65 Modbus gateway. Communication is wireless thanks to the EnOcean technology, with two SRE repeaters ensuring strong signal transmission even in areas with weaker reception
Wireless communication also connects the sensors used to measure room conditions, providing RATP with tangible benefits. In addition to flexible sensor placement, installation was quick and easy due to the absence of cabling. In total, the depot features NOVOS 3 SR room sensors and MCS multi-compact sensors, used to reliably measure room temperature, humidity and CO₂ levels, as well as light levels and occupancy. These are complemented by various room temperature sensors, motion and light detectors as well as outdoor light sensors – altogether allowing for a comprehensive detection of all parameters essential for demand-based and energy-efficient control of room temperature, heating, and lighting. In the canteen, the energy-harvesting radiator valve SAB+ with its continuous room-based control adds further value.
The sensor’s power supply is highly cost-effective due to the absence of batteries or power supply. Equipped with solar cells and intelligent energy-harvesting technology, the sensors significantly reduced installation efforts. Thanks to their energy-autonomous operation and maintenance-free design, they save both time and cost in everyday use for years. This also applies to the electric radiator valve SAB+, which generates the required operating energy by using the temperature difference between the supply temperature and the ambient temperature.
Flexible Implementation – High Energy Efficiency
The responsible team at RATP is highly satisfied with the outcome: “With the Thermokon portfolio, we succeeded in implementing a flexible and tailored building automation solution for our depot. We benefit from significant time and cost savings both during installation and daily operation. The improved energy efficiency also enables us to lead by example when it comes to sustainability.”
