Modern Technologies for Uninterrupted Power Supply: Breakthroughs, Significance, Vulnerabilities, Environmental Sustainability and Global Best Practices

This paper systematizes the technological landscape of assured and uninterrupted power supply systems as it stood in the mid-2020s. It shows that the industry's center of gravity has shifted from the conventional combination of “diesel generator + static UPS” toward four interrelated areas: grid-scale battery energy storage systems (BESS), grid-forming inverters, self-healing distribution networks based on FLISR algorithms, and independently operating microgrids. Quantitative evidence of this turning point is drawn from reports by the International Energy Agency, BloombergNEF, EPRI and ENTSO-E: global storage additions reached a record 108 GW in 2025 (+40 % compared with 2024), lithium-ion battery pack prices fell to USD 108/kWh, and the storage failure incident rate declined by 97 % over 2018–2023. At the same time, systemic vulnerabilities are identified: a shift in failures from cells to integration and installation, insufficient voltage and reactive power control capabilities (as confirmed by the final ENTSO-E report on the Iberian blackout of 28 April 2025), geographical concentration of manufacturing supply chains, a shortage of storage technologies with durations exceeding eight hours, and grid connection queues totaling more than 2500 GW. Environmental issues are examined through the lens of Regulation (EU) 2023/1542, which establishes mandatory recycling efficiency targets and a digital battery passport. Global best practices are summarized in tables with verified numerical results.