This factsheet from the Green Powered Future Mission (GPFM) explores the critical role of energy storage in enhancing power system flexibility amid growing renewable energy integration. It presents international case studies on innovative storage technologies—including flow batteries, second-life lithium-ion applications, and AI-controlled systems—that support grid stability, reduce curtailment, and provide ancillary services. The report highlights scalable and sustainable storage solutions that enable higher renewable penetration, improve market coordination, and contribute to a resilient, decarbonized electricity future.