The chal­lenge for India’s renew­ables surge: Stor­age

Why in News?

India’s rapid expansion of renewable energy capacity has brought attention to a major challenge: energy storage. Since solar and wind energy generation is intermittent and does not always match electricity demand patterns, concerns are growing about grid stability and the ability of India’s power system to absorb increasing renewable energy. Recent assessments by the Central Electricity Authority (CEA) have highlighted storage requirements for India’s future energy transition.

UPSC Relevance

Prelims:

Renewable energy, Energy storage technologies, Pumped Hydro Storage, Battery Energy Storage Systems, CEA, Non-fossil fuel targets.

Mains:

GS III: Energy sector, Infrastructure, Renewable energy transition, Energy security, Sustainable development.

Background/Context

India is pursuing an ambitious clean energy transition to reduce dependence on fossil fuels and meet climate commitments. Renewable energy sources now account for around 53% of India’s installed power generation capacity, with solar power contributing more than 150 GW.

However, renewable energy generation faces an inherent challenge: intermittency. Solar generation ceases after sunset, while wind generation fluctuates according to weather conditions. Electricity demand, meanwhile, continues throughout the day and often peaks during evening hours when solar output declines.

This creates a mismatch between electricity generation and consumption, making energy storage a critical requirement for maintaining grid reliability and ensuring efficient renewable integration.

Energy Storage: Meaning and Importance

Energy storage systems capture excess electricity generated during periods of high renewable output and release it when demand rises or generation declines.

The major objectives of energy storage include:

Grid stability

Storage systems help maintain continuous electricity supply despite fluctuations in renewable generation.

Peak demand management

Stored electricity can be supplied during periods of high demand, reducing stress on the grid.

Renewable energy integration

Storage enables larger quantities of renewable power to be absorbed into the system.

Energy security

It reduces dependence on conventional thermal power and improves resilience against supply disruptions.

Major Energy Storage Technologies

Pumped Hydro Storage (PHS)

Pumped hydro storage uses surplus electricity to pump water from a lower reservoir to a higher reservoir. During peak demand periods, stored water flows downward through turbines to generate electricity.

Advantages include long operational life, large storage capacity, and relatively low operational costs.

Battery Energy Storage Systems (BESS)

Battery systems chemically store electricity and discharge it when needed. Lithium-ion batteries, especially Lithium Iron Phosphate (LFP) batteries, currently dominate due to improving efficiency and declining costs.

Advantages include rapid response capability and flexibility in deployment.

Concentrated Solar Thermal Storage

This technology uses mirrors to concentrate sunlight and heat materials such as molten salts. The stored heat later generates steam and electricity.

Compressed Air Energy Storage

Excess electricity compresses air into underground reservoirs or tanks. The compressed air is later released to operate turbines and produce power.

Flywheel Energy Storage

Flywheels store electricity as rotational kinetic energy through rapidly spinning rotors and are useful for managing short-term grid fluctuations.

Gravity Energy Storage

Heavy weights are lifted using surplus electricity and later lowered to convert gravitational potential energy into electricity.

India’s Energy Storage Status

India’s renewable energy expansion has significantly outpaced storage deployment.

Current installed capacity includes:

• Battery Energy Storage Systems: Around 0.27 GW
• Pumped Hydro Storage: Around 7.2 GW

The CEA projects that by 2035–36 India will require:

• Total storage capacity: 174 GW/888 GWh
• Battery Energy Storage: 80 GW/321 GWh
• Pumped Hydro Storage: 94 GW/567 GWh

The CEA has also noted that storage systems with four-to-six-hour duration will become increasingly important as renewable energy penetration rises.

Project Pipeline and Expansion Plans

Pumped Hydro Projects

India currently has substantial projects under various stages:

Under construction: Around 13,120 MW

Approved and awaiting construction: Around 9,580 MW

Under survey and investigation: Nearly 75,000 MW

Battery Storage Projects

Battery storage deployment is also increasing:

Under construction: Approximately 10,659 MW

Tendering stage: Approximately 22,347 MW

Challenges

Import Dependence

India imports nearly 75–80% of lithium-ion battery cells, which constitute a large share of total battery costs. Such dependence creates vulnerabilities relating to geopolitical tensions, trade restrictions, and price volatility.

Intermittent Renewable Generation

The mismatch between generation and consumption patterns creates pressure on grid management and increases balancing requirements.

High Initial Costs

Battery systems and pumped hydro projects require significant capital investment, affecting large-scale deployment.

Land and Environmental Constraints

Pumped hydro projects require suitable topography and may create ecological and rehabilitation concerns.

Technology and Supply Chain Risks

Concentration of battery manufacturing among a few countries creates strategic vulnerabilities and supply chain uncertainty.

Global Scenario

Globally, Pumped Hydro Storage and Battery Energy Storage Systems dominate energy storage deployment.

Pumped Hydro Storage currently stands at around 160 GW globally, with:

• China: Nearly 66 GW
• Japan: Around 21.8 GW
• United States: Around 18.9 GW
• Europe: Around 28 GW collectively

Battery storage deployment is expanding rapidly, with approximately 270 GW installed globally. China contributes nearly 60% of recent global battery additions, followed by the United States and Europe.

Countries such as Australia and several Middle Eastern nations are also increasingly viewing storage as essential for energy security and renewable integration.

Challenges in India’s Renewable Transition

Storage-Gap Challenge

Rapid renewable energy additions without corresponding storage expansion may affect grid reliability and create balancing difficulties.

Manufacturing Capacity Deficit

India lacks sufficient domestic manufacturing capability for advanced battery technologies.

Financing Constraints

Large investments are required to scale up storage infrastructure and attract private participation.

Policy and Regulatory Issues

Clear market structures and pricing mechanisms for storage services are still evolving.

Way Forward

Strengthen Domestic Manufacturing

India should expand domestic battery manufacturing under schemes such as Production Linked Incentive (PLI) initiatives to reduce import dependence and build supply chain resilience.

Diversify Storage Technologies

Excessive reliance on a single technology should be avoided. India should simultaneously promote pumped hydro, batteries, compressed air systems and emerging storage technologies.

Develop Long-Duration Storage

Future renewable expansion will require storage systems capable of supporting electricity supply over longer periods rather than only short-duration balancing.

Improve Policy Framework

Stable regulations, viability gap funding and market-based incentives can encourage investment in storage infrastructure.

Promote Research and Innovation

Greater investment in advanced battery chemistry, recycling technologies and alternative storage solutions can strengthen long-term energy security.

Conclusion

India’s renewable energy transition has reached a stage where expanding generation capacity alone is insufficient. The success of the clean energy transition increasingly depends on the development of reliable storage infrastructure. Moving from a renewable-energy expansion strategy to an integrated renewable-plus-storage approach will be essential for ensuring energy security, grid stability and sustainable economic growth.

Practice Questions

Prelims Question 1

With reference to Pumped Hydro Storage (PHS), consider the following statements:

1. It stores energy by pumping water from a lower reservoir to a higher reservoir.
2. It can generate electricity during peak demand periods.
3. It depends on chemical reactions for energy storage.

Which of the statements given above is/are correct?

(a) 1 and 2 only
(b) 2 and 3 only
(c) 1 only
(d) 1, 2 and 3

Correct Answer: (a)

Explanation: Statements 1 and 2 are correct. Pumped Hydro Storage uses gravitational potential energy and does not rely on chemical reactions.

Prelims Question 2

Consider the following statements regarding Battery Energy Storage Systems (BESS):

1. Lithium-ion batteries are among the most widely used battery technologies.
2. Battery systems help manage fluctuations in renewable power generation.
3. India currently manufactures all of its lithium-ion battery requirements domestically.

Which of the statements given above is/are correct?

(a) 1 and 2 only
(b) 1 and 3 only
(c) 2 and 3 only
(d) 1, 2 and 3

Correct Answer: (a)

Explanation: Statements 1 and 2 are correct. India still imports a substantial portion of its lithium-ion battery requirements.

Mains Question

1. India’s renewable energy transition increasingly depends on energy storage systems. Examine the challenges and opportunities associated with scaling up energy storage infrastructure in India.
2. Discuss the role of energy storage technologies in ensuring energy security and grid stability in India’s transition towards a low-carbon economy.