UPSC Prelims Practice Questions — India’s green transition is missing long-duration energy storage

Q1. India's Long-Term National Resource Adequacy Plan (2026-27 to 2035-36), which formalised the 80 GW battery / 94 GW pumped-hydro storage target mix, was released by which authority?

  • A. The Central Electricity Regulatory Commission (CERC)
  • B. The Bureau of Energy Efficiency under the Ministry of Power
  • C. The Central Electricity Authority (CEA) under the Ministry of Power
  • D. The Grid Controller of India (Grid-India)

Q2. As per the CEA's Long-Term National Resource Adequacy Plan (2026-27 to 2035-36), how much pumped hydroelectric energy storage (PHES) capacity is projected by FY2035-36?

  • A. 80 GW
  • B. 94 GW
  • C. 100 GW
  • D. 208 GW

Q3. Consider the following statements comparing long-duration energy storage (LDES) with the storage in India's current adequacy plan: 1. LDES is generally defined as storage able to discharge continuously for about 8 hours or more, extending to multi-day durations. 2. In the CEA plan, battery storage is assigned an average discharge duration of about 4 hours and pumped hydro about 6 hours. 3. At their planned average durations, both the battery and pumped-hydro storage in the plan individually qualify as long-duration energy storage. Which of the statements given above is/are correct?

  1. LDES is generally defined as storage able to discharge continuously for about 8 hours or more, extending to multi-day durations.
  2. In the CEA plan, battery storage is assigned an average discharge duration of about 4 hours and pumped hydro about 6 hours.
  3. At their planned average durations, both the battery and pumped-hydro storage in the plan individually qualify as long-duration energy storage.
  • A. 1 and 2 only
  • B. 2 and 3 only
  • C. 1 and 3 only
  • D. 1, 2 and 3

Q4. Which single technology is the largest and most widely deployed form of long-duration, grid-scale energy storage currently in operation worldwide?

  • A. Pumped hydro storage
  • B. Lithium-ion battery storage
  • C. Flow battery storage
  • D. Compressed air energy storage

Q5. With reference to India's record peak power demand of May 2026, consider the following statements: 1. India recorded its highest-ever peak power demand of 270.8 GW on May 21, 2026. 2. Renewable energy, including hydro, contributed about 34% to the peak demand of that day. 3. The record peak was reached during late-night, non-solar hours around midnight. 4. Maharashtra registered the highest state-level demand during that peak. Which of the statements given above is/are NOT correct?

  1. India recorded its highest-ever peak power demand of 270.8 GW on May 21, 2026.
  2. Renewable energy, including hydro, contributed about 34% to the peak demand of that day.
  3. The record peak was reached during late-night, non-solar hours around midnight.
  4. Maharashtra registered the highest state-level demand during that peak.
  • A. 1 and 2
  • B. 3 only
  • C. 2 and 4
  • D. 1, 2 and 4

Q6. India's record peak demand of 270.8 GW in May 2026 was reported to be about 90 GW higher than the demand in the equivalent seasonal window of which earlier year?

  • A. 2016
  • B. 2014
  • C. 2019
  • D. 2022

Q7. The National Electricity Plan (2023) of the CEA projected an approximate battery energy storage (BESS) requirement of how much energy capacity by 2030?

  • A. 336 GWh
  • B. 411 GWh
  • C. 236 GWh
  • D. 208 GWh

Q8. In the National Electricity Plan (2023), the ~208 GWh storage requirement projected for 2030 is attributed primarily to which single storage technology?

  • A. Pumped hydro storage
  • B. Battery Energy Storage Systems (BESS)
  • C. Flow battery storage
  • D. Compressed air energy storage

Q9. The Guidelines for Resource Adequacy Planning Framework (2023), which embedded energy storage as a core planning resource for distribution utilities, were issued by which authority?

  • A. The Ministry of Power
  • B. The Central Electricity Authority
  • C. The Central Electricity Regulatory Commission
  • D. The Ministry of New and Renewable Energy

Q10. With reference to the National Framework for Promotion of Energy Storage Systems (2023), consider the following stated objectives/components: 1. Providing a roadmap for the deployment of energy storage systems. 2. Facilitating market integration and a regulatory framework for storage. 3. Enhancing grid stability and enabling peak/energy shifting through storage. 4. Mandating the retirement of all thermal power plants older than 25 years by 2030. Which of the statements given above is/are NOT correct?

  1. Providing a roadmap for the deployment of energy storage systems.
  2. Facilitating market integration and a regulatory framework for storage.
  3. Enhancing grid stability and enabling peak/energy shifting through storage.
  4. Mandating the retirement of all thermal power plants older than 25 years by 2030.
  • A. 1 and 3
  • B. 2 only
  • C. 4 only
  • D. 3 and 4

Q11. In India, techno-economic concurrence to pumped hydroelectric storage (PHES) projects is accorded by which authority?

  • A. The Central Water Commission
  • B. The Central Electricity Regulatory Commission
  • C. The Central Electricity Authority
  • D. The National Hydroelectric Power Corporation

Q12. Consider the following statements about renewable-generation droughts and grid resilience in India: 1. A renewable-generation drought refers to prolonged periods — such as cloudy, still spells or heatwave-driven still nights — when both solar and wind output fall well below normal. 2. The May 2026 record demand showed the daily peak shifting entirely into solar hours, effectively eliminating the night-time peak problem. 3. Multi-day renewable droughts expose the limits of ~4-6 hour storage, strengthening the case for long-duration energy storage. Which of the statements given above is/are correct?

  1. A renewable-generation drought refers to prolonged periods — such as cloudy, still spells or heatwave-driven still nights — when both solar and wind output fall well below normal.
  2. The May 2026 record demand showed the daily peak shifting entirely into solar hours, effectively eliminating the night-time peak problem.
  3. Multi-day renewable droughts expose the limits of ~4-6 hour storage, strengthening the case for long-duration energy storage.
  • A. 1 and 2 only
  • B. 1 and 3 only
  • C. 2 and 3 only
  • D. 1, 2 and 3