A container-based static storage system has been installed at the Fuencarral depot, incorporating second-life batteries originally used in Irizar e-mobility electric buses. While these batteries no longer offer sufficient capacity for the vehicles, they remain suitable for stationary applications.
The storage container is designed to operate as part of EMT Madrid’s smart charging system. By charging during off-peak periods and discharging during peak demand, the system aims to reduce power and demand peaks during bus charging, optimise energy consumption and lower associated costs.
The container has a maximum energy capacity of 1 MWh and a charging and discharging power of up to 500 kW. It comprises fifteen battery racks recovered from three Irizar e-mobility vehicles and is fully managed through EMT’s existing smart charging platform, which is used daily to charge the electric bus fleet at Fuencarral.
Irizar e-mobility emphasises that it has been designing and manufacturing its own batteries for more than seven years, and the reuse of batteries has been a priority within its approach to circular economy solutions. Daily charging cycles gradually reduce battery capacity over time, making replacement necessary once a certain level of degradation is reached to ensure reliable bus operation. The reuse of these batteries in stationary applications addresses one of the key challenges of electric mobility by extending their useful life beyond vehicle operation.
According to the project partners, the second-life storage system not only provides a practical and economical solution for depot charging but also contributes to environmental sustainability. Extending battery lifespans reduces the need to manufacture new batteries, lowering the demand for raw materials and reducing environmental and social impacts.
The project forms part of Spain’s PERTE VEC programme and supports EMT Madrid’s broader strategy to decarbonise public transport through zero-emission vehicles, upgraded infrastructure and smart energy management technologies.
irizar-emobility.com, emtmadrid.es, iberdrolaespana.com
