An innovative project by Iberdrola España extends the lifespan of electric bus batteries for EMT Madrid

In partnership with Iberdrola España and Irizar e-mobility, EMT is developing a project to reuse electric batteries at its Fuencarral operations centre. On the morning of Wednesday, 16 December, Carlos Pascual López, head of energy management solutions at Iberdrola España, and Eduardo Montejo, Iberdrola España's institutional representative in Madrid visited the facility accompanied by Madrid Municipal Transport Company (EMT) executives. 

A container for static electrical energy storage has been installed at this site, incorporating second-life batteries. These batteries are not suitable for use as traction batteries, since as the device ages its storage capacity decreases, which limits the autonomy of the vehicles too much. 
 

Iberdrola España, as the energy partner in this project, which is part of the Strategic Projects for Economic Recovery and Transformation for connected and electric vehicles, has worked together with EMT on the technical specification and field validation of the prototype installed to support the high-power infrastructure, with the ultimate goal of reducing costs and improving efficiency by optimising the battery. For its part, Irizar e-mobility, as a strategic partner, has designed and technically developed the second-life battery power storage container with the main objective of optimising energy consumption in operations centres and making energy management more flexible.

Batteries are an essential component of electric buses, as they store the electrical power the motor needs to run the vehicle . Therefore, the vehicle's range depends largely on the battery’s capacity at any given time. The batteries are charged daily, which gradually reduces their storage capacity for use as traction batteries. This combination of factors means that at a certain degree of degradation they must be replaced to ensure optimal bus operation.  
 

The end of the batteries' first life and their subsequent reuse poses a challenge for the Municipal Transport Company, which is tackling one of the most important challenges of electric mobility with this project: extending the useful life of batteries and using them once they no longer have optimal charging and discharging capacity.

EMT is committed to the use of second-life batteries as a backup for recharging its buses to use them as an integrated element in its smart charging system to reduce power and demand peaks during normal battery charging hours, optimising the charging process and reducing associated costs. 

In addition to offering a practical and economical solution to battery charging, the project also makes a significant contribution to environmental sustainability and the circular economy: extending the service life of batteries means reducing the need to manufacture new ones, thereby decreasing the use of certain raw materials and achieving a consequent reduction in their environmental and social impact. All of this consolidates a cleaner, more efficient and more responsible public transport and paves the way for contributing to a more flexible and renewable electricity system in the future.