The Barcelona Metro has introduced a new technology to increase the energy efficiency of its urban rail transport systems. Instead of converting to heat, the kinetic energy generated when trains brake as they approach stops is now converted into electrical energy. This energy can be used both within the metro system and at electric vehicle charging stations.
Electricity Generated from Braking Energy
Trains stopping at each stop on the metro consume a significant amount of energy. Until now, much of this energy was converted to heat during braking and wasted. With the new system implemented in Barcelona, this energy is recovered and transferred to the electricity grid, thus preventing energy waste and reducing the carbon footprint of urban transportation.
The regenerative braking system, common in electric vehicle technologies, is also being used in the Barcelona Metro. This method is not widely applicable on intercity train lines because trains rarely brake over long distances and do not have battery systems to store the electricity generated. Furthermore, such lines lack adequate infrastructure to power the energy.
In contrast, this system can directly provide efficiency on urban trains due to the frequent stops and high energy consumption over short distances. Because the generated electricity can be used instantly, there is no need for energy storage.
The Barcelona metro operator plans to recover 41 percent of the total energy consumed to run the trains with this system. The project, which has invested €7.3 million, is expected to pay for itself within five years.
The recovered electricity is used to power other trains in the metro system, escalators in stations, lighting, and even electric vehicle charging points outside stations. This way, the energy needs of 25 different stations can be met.
The new system not only saves energy but also offers air conditioning advantages. Because the energy generated during braking is no longer converted to heat, the temperature of the metro tunnels has decreased by an average of 1 degree Celsius.
