Melilla’s isolated power grid now has a backup system built from 78 electric-car battery packs, most retired from Nissan LEAF vehicles. The Second Life project brings together Enel, Endesa, Nissan and Loccioni. Installed at the city’s thermal power plant, it is designed to provide up to 15 minutes of electricity if the basic supply fails, helping protect services used by Melilla’s 90,000 residents.
Endesa reports that the system is rated at 4 MW and stores 1.7 MWh. The figures measure different things: power is the rate at which electricity can be delivered, while energy is the amount stored. A constant 4 MW output from 1.7 MWh would last about 25.5 minutes in a theoretical calculation. The reported operating window of up to 15 minutes accounts for operating constraints and conversion losses, while leaving reserves available. This is a short-term bridge, not a replacement for the thermal plant or a source of power for prolonged citywide supply.
Melilla runs an isolated electrical network, with no connection to Spain’s mainland grid that could provide immediate support if local generation fails. Fast-response storage can help stabilize the system while operators restore or adjust generation. The project is intended to give them time to respond and support impressive services, including hospitals and businesses. Traffic signals also depend on continuity of supply.
How the Backup Works
The installation combines 48 used battery packs with 30 new units. The used packs, mainly from Nissan LEAF vehicles, are no longer suited to automotive demands but can retain capacity for stationary storage. In a fixed installation, weight and volume matter less than they do in a vehicle. Batteries can also be managed through controlled charge-and-discharge cycles. The project connects the packs without dismantling them into individual cells, extending their use while avoiding that extra processing step.
When the grid needs support, the system can inject electricity for up to 15 minutes. In an isolated network, that brief response can help operators manage a sudden loss of generation and work to restore supply. Its practical contribution depends on the power being dispatched and the energy available at the time. The 4 MW rating alone does not show how long the system can sustain a particular output.
Why Second-Life Batteries Matter
Vehicle batteries can lose performance for driving while retaining potential for stationary applications. A pack that no longer meets a car’s needs may still store and deliver energy in a fixed installation, where range and acceleration are irrelevant. Reusing packs before recycling can extend the useful life of their materials. Stationary systems still need suitable battery management, monitoring and safety controls.
Endesa says the system is integrated into the plant’s operations to strengthen supply reliability. The approach follows a circular-economy model in which products are reused or repurposed before their materials are recycled. Nissan has also pursued battery reuse and recycling initiatives in Japan through 4R Energy Corporation. The company’s work focuses on reusing, refurbishing, reselling and recycling lithium-ion batteries.
In The Future
As electric-vehicle use grows, more batteries will reach the point when they are no longer suitable for automotive service. Melilla’s Second Life installation shows how some packs can be repurposed for stationary storage, particularly in isolated electricity systems where rapid backup can help bridge a disruption. The system is designed to provide a short buffer, not replace local generation or guarantee that outages will be prevented.
Melilla is giving used vehicle batteries a role in grid support, demonstrating one way to combine energy ability to recover with battery reuse. The system’s 4 MW output rating and 1.7 MWh storage capacity define its scale. Its reported 15-minute backup window describes the intended operational role during a supply interruption.
