India’s green transition is missing long-duration energy storage, Pg2

Key Highlights:

• India recorded its highest peak power demand of 270.8 gigawatts (GW) on May 21, highlighting the need for enhanced energy storage.
• The current Long-Term National Resource Adequacy Plan aims for 80 GW of battery energy storage and 94 GW of Pumped Hydroelectric Energy Storage (PHES) by FY2035-36.
• These plans offer short-duration storage (4-6 hours), which may be insufficient for prolonged periods of low renewable generation or adverse weather conditions.
• Long-Duration Energy Storage (LDES) technologies, capable of discharging power for days rather than hours, are identified as a missing pillar for India's green energy transition.
• India has initiated projects like a 160-MWh carbon dioxide battery storage system at NTPC Kudgi and a 3-MWh vanadium redox flow battery at NTPC Greater Noida.

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Detailed Insights:

• LDES systems provide grid resilience and stability by balancing supply and demand over extended periods, unlike short-duration systems that manage intra-day fluctuations.
• PHES remains the benchmark LDES technology due to its mature infrastructure and high energy efficiency of 70-80%.
• Compressed-Air Energy Storage (CAES) offers similar market readiness but with lower efficiency (40-70%).
• Thermal storage, while still under development, shows promise with long discharge durations of around 200 hours and 55-90% efficiency.
• Vanadium flow batteries are commercially ready, offering 80-85% efficiency for 10-24 hour discharge durations.
• The Central Electricity Authority (CEA) reported India's PHES potential at 267 GW, with plans to install 100.8 GW by 2035-2036.
• Current national energy plans lack specific recognition and deployment pathways for LDES, necessitating its incorporation into the Ministry of Power's National Framework for Promoting Energy Storage Systems.
• Policy recommendations include faster environmental clearances, technology-agnostic incentives, and training for dispatch centers to manage LDES assets effectively.

Key Concepts Involved:

• Long-Duration Energy Storage (LDES): Technologies that store and discharge energy for extended periods, typically from 8 hours to several days or weeks.
• Pumped Hydroelectric Energy Storage (PHES): A mature LDES technology that stores energy by pumping water to an upper reservoir and releasing it to generate electricity when needed.
• Compressed-Air Energy Storage (CAES): An LDES technology that stores energy by compressing air into underground caverns and releasing it to drive turbines.
• Vanadium Flow Batteries: A type of electrochemical LDES that uses vanadium ions in different oxidation states to store and release electrical energy.