Paris has one of the world’s densest and oldest subway networks. Automation technology from Siemens is making the system more energy efficient. Meanwhile, light sensors are helping buildings to cut power consumption.
In Paris the air is burning - literally. As you stroll through the city, it’s impossible to miss the many small mushroom heaters blazing away on café terraces and inside poorly-insulated brasserie conservatories. Even though they only burn for a few hours a day during the chilly months of the year, each one of them generates as much carbon dioxide per year as a mid-sized automobile. Yet who would be so mean as to forbid the Parisians to use their patio heaters? After all, when temperatures fall, how else can they enjoy a petit noir outdoors, either after work or on the go?
For many Parisians, saving energy is important but should not compromise the French way of life. Public transport is a good example of how this can work out. Here, too, comfort is the prime motivation, though there’s good reason for that. Only 20 percent of commuters travel by foot or bike, compared to 68 percent in Stockholm. At first that seems surprising. After all, there is a widespread network of bike paths in Paris, and autho - rities created a bike rental system in 2007, with 20,000 bikes at 1,450 automatic stations, all free of charge for the first 30 minutes.
One of the main reasons Parisians prefer not to use pedal power is the superb subway system right at their doorstep. It is not only one of the densest metro networks in the world but also, at 214 kilometers, one of the longest. The first station opened in July 1900 to mark the World’s Fair. In fact, many of the stations are showing their age and can hardly cope with today’s rush-hour passenger volumes.
One way of raising throughput is to reduce intervals between trains. This is now being done on Line 1 - the oldest and, with 750,000 passengers a day, one of the most frequented routes - in a joint project between the Paris transport authority RATP and Siemens. In fact, Siemens has been supplying the Paris Metro lines with signaling technology and advanced driver assistance systems for the past 30 years. Now there are plans to introduce driverless trains on Line 1 - with Siemens technology.
At present, stations are being fitted with glass walls to separate platforms from tracks. These will incorporate automatic doors that open to let passengers safely enter trains. This will help to reduce maintenance costs and cut the current intervals between trains from 105 to around 85 seconds, as well as increasing flexibility and reliability. Such fully automatic subway trains with Siemenstechnology have been in service on Line 14 of the Paris Metro for 12 years. With an average speed of 40 km/h, it is substantially faster than the other lines, which operate at around 25 km/h.
Seventy Percent Less for Lighting. Energy saving continues after the daily Metro ride to work - at least for employees at the Parisian headquarters of the OECD, the Organisation for Economic Co-operation and Development. Although parts of the building are 50 years old, it is now able to adapt automatically to prevailing weather conditions. In the course of general refurbishment, a Dali Multi intelligent lighting system from Siemens’ subsidiary Osram was installed. The system comprises around 1,000 lamps with sensors that determine how much light is actually required and then tailor the lamps’ output accordingly. The lamps have replaced conventional ceiling lighting that provided each workstation with constant illumination throughout the day. Whenever employees leave their offices for a longer period, the lights now go off automatically. Similarly, when it’s cloudy and less natural light enters through the windows, the lamps automatically brighten.
Independent measurements have shown that energy consumption for lighting has fallen by as much as 70 percent compared to before the refurbishment. Bernard Balia, former head of facility management at OECD, was responsible for the project. “The system makes us more adaptable. Instead of everyone having uniform lighting, employees can now help to determine the right amount of light for their needs. And the system is economical, since lights only get switched on when they are actually needed,“ he says.
Outside, on café terraces, patio heaters continue to singe the Parisian air whether anyone is there or not. Perhaps one day they too will be fitted with sensors, allowing them to blaze into life only when actually needed. After all, when it comes to preserving the French way of life, some small sins should be permissible - if, that is, real crimes against the environment are avoided.