The recent project developed in Madrid by the Municipal Transport Company, in collaboration with Irizar e-mobility and Iberdrola, represents a significant milestone in the evolution of electric mobility and urban energy management. The initiative is based on reusing batteries that have reached the end of their service life in electric buses and giving them a second life as stationary energy storage systems. This approach not only extends the value of a critical and costly component, but also provides a concrete solution to one of the main challenges of public transport electrification: the energy costs associated with charging operations and the pressure placed on the electrical grid.
The implemented system allows energy to be stored during periods of low demand or lower electricity prices and then used during peak consumption periods, particularly when multiple electric buses are charging simultaneously. As a result, peak demand charges are reduced, overall energy consumption is optimized, and the need for major investments in grid reinforcement is mitigated. At the same time, the use of second-life batteries reinforces the principles of the circular economy by delaying the final recycling phase of these components and reducing the demand for new batteries, whose production involves significant environmental impacts and the intensive use of critical raw materials.
The relevance of this model for Latin America is especially significant. In many cities across the region, public transport remains one of the main sources of air pollution and greenhouse gas emissions, while public budgets are often constrained and highly sensitive to operating costs. In this context, the electrification of bus fleets represents a clear opportunity to improve air quality and advance national climate commitments, but it also introduces financial and technical challenges that are not always easy to overcome. The integration of energy storage systems based on reused batteries can help make this transition more economically viable.
Furthermore, Latin America has strong potential for renewable energy generation, particularly solar and wind. Combining these energy sources with second-life battery storage systems would increase the share of clean energy used in public transport operations, improve supply stability, and reduce dependence on electrical grids that, in some countries, still face capacity or reliability constraints. Such solutions can also stimulate the development of local value chains linked to battery assessment, refurbishment, management, and recycling, creating employment opportunities and strengthening technical capabilities.
However, implementing a model similar to Madrid’s in Latin America requires clear enabling conditions. Robust regulatory frameworks are needed to recognize and promote the use of second-life batteries, along with financing mechanisms that facilitate partnerships between transport operators, energy companies, and technology providers. Equally important is investment in technical training and energy management systems to ensure the safety, reliability, and efficiency of these storage solutions throughout their lifecycle.
In conclusion, the experience of EMT Madrid demonstrates that reusing electric bus batteries as stationary energy storage systems is a mature and viable solution, delivering tangible benefits in terms of cost reduction, sustainability, and operational efficiency. For Latin America, adopting such models could not only accelerate the electrification of public transport, but also help lay the foundations for a more efficient, resilient, and circular energy transition, provided it is supported by strong public policies and a long-term strategic vision.
