Reducing temperature set point in regional trains in Paris (RATP)

RATP operates an extended regional rail network (RER) with three types of regional trains. The temperature was originally set at 18°C during the winter in all vehicles. The project involved lowering the point temperature from 18°C to 15°C. Measurements were made during operating times to estimate the potential of energy savings for each rolling stock model. The energy savings ranged from 6% to 32%.

The energy savings amounted to an average of 40,000 kWh per train element every year and the resulting GHG emissions could be reduced by 1.7 TCO2 for each vehicle. This resulted in cost savings of around €2,400 per train element annually. As far as staff resources are concerned, four persons worked for one month to adapt all vehicles.
Technical data

Investment costs (€)


Staff resources

One day / vehicle

Energy savings (%)

From 5% to 30%, depending on the vehicle

Annual energy savings (kWh)

40,000 kWh/vehicle

Annual CO2 savings (TCO2)

1.7 TCO2/vehicle

Annual cost savings (€)


Payback time (years)

Less than one year