The 20-MW (40 MWh) BESS installed at the BRPL (BSES Rajdhani Power Limited) substation  is also India’s “first commercially approved” utility-scale energy storage system .

• It leverages advanced Lithium Iron Phosphate (LFP) technology known for superior safety, thermal stability and durability.
• In Lithium–iron phosphate (LiFePO4) batteries, cathode is made of lithium metal phosphate instead of lithium metal oxide.

Battery Energy Storage Systems (BESS)

• About: Electrochemical Energy Storage Systems that stores electrical energy from renewables in the form of chemical energy to be used during peak demand. 
• Significance: Cater to Future needs (236 GWh BESS would be required by 2031-32 as per National Electricity Plan, 2023); smooth renewable energy fluctuations, etc. 
• Two Main Categories
  • Traditional Solid Rechargeable Batteries: Stores Energy in solid metal electrodes, Examples:
    • Lead Acid Batteries (Anode- lead, Cathode- Lead dioxide)
    • Lithium Ion Batteries [Anode- Graphite, Cathode- Lithium Oxide (LiMO2; M=Co, Ni)]
    • Zinc Air Batteries (Anode- Zinc, Cathode- Air/Oxygen). 
    • Sodium Sulphur (NaS) (Anode- Sodium, Cathode- Sulfur). 
  • Flow batteries: Energy is stored in flowing liquid electrolytes kept in tanks separately. Example, vanadium redox flow batteries, zinc-iron flow batteries, zinc-bromine batteries, etc.