Every year, thousands of hybrid vehicle battery modules are removed from service because they no longer satisfy the demanding performance requirements of automotive use. While many of these modules can be reconditioned and returned to hybrid vehicles through the Green Zone, others no longer meet automotive standards even though they still retain substantial energy storage capability. 
 
Rather than sending these valuable modules directly to recycling, TECRE proposes giving them a second life as community energy storage. 
 
By extending the useful life of retired battery modules, Puerto Rico can create jobs, strengthen energy resilience, reduce waste, and build a practical circular battery economy that benefits both people and the environment. 
 
Figure 1 illustrates the flow of battery modules through Puerto Rico’s proposed circular battery economy, from automotive use to reconditioning, community energy storage, and ultimately material recovery. 

Many low-income communities in Puerto Rico experience frequent electrical outages. In communities such as the G8 surrounding the Caño Martín Peña, many homes have lightweight galvanized steel roofs that are not suitable for supporting rooftop solar panels. For this reason, the Yellow Zone is designed as a standalone battery backup system rather than a rooftop solar installation. 
 
Residents simply receive a fully assembled battery box that is ready to provide electricity whenever the grid fails.