Discuss the role of Battery Energy Storage Systems in addressing intermittency and curtailment in a high-RE grid. What policy support does India need to scale domestic BESS manufacturing?

Solar and wind make up 37% of India's installed capacity but produce only 13% of its electricity [1]. The main reason is intermittency: the sun and wind are not always available. Battery Energy Storage Systems (BESS) store surplus power and release it when needed. The 50 GWh BESS component of Green Energy Corridor Phase-III shows they are becoming central to grid planning [2].

Role of BESS in addressing intermittency

• Time-shifting: batteries store surplus solar power at midday and release it at the evening peak, meeting non-solar-hour demand [2].
• Smoothing: batteries respond in seconds, which damps output swings caused by clouds or changes in wind and keeps the grid stable.
• Firming: storage at the generator end turns variable output into power that can be scheduled [2].

Role in reducing curtailment

• Congestion relief: BESS placed at key points for grid flexibility absorbs power that the lines cannot carry, which cuts peak-hour curtailment [2].
• Buffer for slow transmission: only 58% of targeted transmission lines were added in 2024-25 [1], so storage can hold back power where new lines are delayed.
• Limits: a 4-hour, 50 GWh battery can supply about 12.5 GW, which is under a tenth of GEC-III's 135 GW [2]. Storage adds to grid expansion but cannot replace it.

Policy support needed for domestic manufacturing

• Steady demand: GEC-III gives ₹50,000 crore for BESS [2], and Viability Gap Funding for BESS takes 3% of the Ministry of Power's budget [1]. These two routes should be merged into one multi-year procurement pipeline so that manufacturers can see orders ahead and projects are not funded twice.
• Cell-level capacity: the PLI scheme for Advanced Chemistry Cells (₹18,100 crore, 50 GWh) [3] needs strict monitoring so that plants are commissioned on time. Its support should also cover grid-scale chemistries such as LFP and sodium-ion.
• Inputs and raw materials: the customs duty exemption on BESS cells [1] should be temporary and tied to phased domestic-content rules. The proposed rare-earth corridors [1] and battery recycling can help secure minerals.
• Market design and standards: storage should be paid for the grid services it provides. BIS safety standards, testing laboratories and R&D for home-grown chemistries are also needed.

BESS is what connects India's large RE capacity to reliable supply, cutting both intermittency and wasted power. Linking assured demand with PLI-backed manufacturing and secure minerals can build a domestic storage industry. This would support the 900 GW non-fossil target by 2035 [2], SDG 7 and the goal of Aatmanirbhar Bharat.