Table of Contents
India, the world’s fifth-largest economy, is on track to achieve an impressive 7% GDP growth by 2024. The energy sector remains a crucial driver of India’s economic progress, undergoing remarkable transformations in recent years.
1.0. Background
India, one of the world’s fastest-growing nations, has undergone significant transformations over the past few decades. As the fifth-largest economy globally, India’s GDP is projected to expand by nearly 7% in 2024, driven by advancements in infrastructure, industries, and improved living standards. Among the key factors fueling this growth, electricity remains a crucial pillar, supporting industrial, rural, and agricultural development.
India has been a pioneer in hydropower generation in Asia, with a legacy spanning over 100 years. The country’s first hydroelectric power plant was established in 1898 at Sidrapong, Darjeeling, West Bengal, with a capacity of 130 kW. This was followed by the Shimsha (Shivanasamudra) power plant in Mysore, built-in 1902 with a 4.5 MW capacity. After independence, hydropower became a key priority for the Indian government, accounting for over 45% of the energy mix in the 1960s. However, this share has declined to just above 11% in 2023.
Globally, nations like Norway, Brazil, and Venezuela depend significantly on hydropower. India is also rich in hydropower potential, estimated at around 148,700 MW. Despite this, only 51.8 GW has been harnessed through small and large hydropower projects. The slow development of hydropower since the 1970s is due to challenges like public opposition to dam projects, land acquisition disputes, resettlement issues, funding limitations, lack of advanced technology, and geological barriers.
To accelerate economic growth, India shifted its focus toward thermal power plants, particularly coal-based ones. Today, coal-fired plants account for nearly 56% of the total installed capacity and meet 75% of the country’s electricity needs. This transition has helped sustain India’s rising energy demands but has also led to environmental concerns.
Coal-fired power plants are a major contributor to greenhouse gas emissions. A 2020 study revealed that the electricity and heat sector contributes around 35% of India’s total emissions, with over 90% coming from coal-fired plants, primarily in the form of CO₂ emissions. As India moves forward, balancing economic growth with sustainable energy solutions will be a key challenge.
2.0. Power growth trajectory in India
India has long depended on coal and oil as its primary sources of electricity generation, resulting in high CO₂ emissions. While the country ranks third globally in carbon emissions, its per capita CO₂ emissions remain among the lowest in the world. To enhance energy security and fulfil its commitment to a Low Carbon Growth Strategy, the Indian government is prioritizing the sustainable development of the power sector, with a strong focus on renewable energy sources, including hydropower.
India’s per capita electricity consumption currently stands at 1,255 kWh, which is just one-third of the global average and one-tenth of the per capita consumption in the United States. Given its large population and ambitious growth targets, India’s energy demand is expected to rise faster than any other country in the coming decades.
To combat climate change, India has set a bold target of achieving net-zero emissions by 2070. The nation plans to meet most of its growing energy needs through low-carbon sources, marking a significant shift from fossil fuels to renewable energy. This transition is a crucial part of India’s global responsibility to minimize climate impact.
Guiding this transformation is the Panchamrit strategy, a five-point action plan designed to accelerate India’s energy transition and pave the way for a sustainable energy future.
- India is set to expand its renewable energy capacity to 500 GW by 2030, marking a significant step toward a sustainable and clean energy future.
- India aims to cut its carbon emission intensity by 45% of GDP by 2030, reinforcing its commitment to a greener and more sustainable future.
- By 2030, 50% of India’s energy will be generated from non-fossil fuel sources, accelerating the country’s shift toward clean and sustainable power.
- India targets a reduction of one billion tonnes in carbon emissions by 2030, compared to 2005 levels, reinforcing its commitment to a cleaner and greener future.
- India is dedicated to reaching net-zero carbon emissions by 2070, demonstrating its strong commitment to a sustainable and low-carbon future.
India has embraced a new economic development model centred on clean energy, ensuring sustainable growth while minimizing its carbon footprint.
2.1. Growth of Renewable Energy
India is steadily increasing its share of renewable energy as part of its commitment to reducing carbon emissions. The country has witnessed an impressive 333% growth in variable renewable energy (solar and wind), expanding from 27 GW in 2015 to 116 GW in 2023. As per the CEA National Electricity Plan, this capacity is projected to soar to around 486 GW by 2031-32.
The rise of renewable energy from 2015 to 2023 is illustrated in Figure 1.0 (Source: CEA).
3.0. Requirement of Energy Storage System (Batteries)
According to the INDC, India targets 500 GW of renewable energy, with 420 GW coming from Variable Renewable Energy (VRE) sources like wind and solar. However, these sources are intermittent, meaning their generation depends on the time of day, seasons, and weather conditions. As India expands its VRE capacity, the power system will undergo significant changes, making the grid increasingly dependent on these energy sources by 2030 and beyond.
Traditionally, power generation was fully controllable, allowing adjustments to match demand. However, VRE generation fluctuates, making it less predictable due to weather variations. This results in periods of excess power on the grid, causing a mismatch between supply and demand. In such cases, surplus power must be stored or utilized, or else VRE generation will be curtailed. Some southern Indian states already experience curtailment when VRE generation surpasses 20% of total energy capacity.
To minimize curtailment risks by 2030, energy storage solutions are essential. Among various storage technologies, Pumped Storage Hydro Projects (PSP), often called water batteries, stand out as the most reliable and domestically available option.
PSP technology is ideal for large-scale grid applications due to its proven reliability, long lifespan, cost-effectiveness, and minimal environmental impact. Unlike chemical batteries, which rely on imported components, PSPs use mainly domestic materials and technology.
PSPs are clean, green, and safe, producing no harmful by-products or disposal concerns. As India advances its renewable energy transition, PSPs will play a crucial role in balancing the grid and ensuring a sustainable power future.
4.0 Water Battery (Pumped Storage Project) concept.
A Pumped Storage Project (PSP) consists of two reservoirs: an upper reservoir at a higher elevation and a lower reservoir at a lower elevation, connected by a Tail Race Tunnel. The civil components of a PSP are similar to those of a conventional hydroelectric project.
Water is pumped from the lower reservoir to the upper reservoir, where it is stored as potential energy. When electricity is needed, the stored water is released, flowing downward due to gravity, turning a turbine, and generating power.
In a PSP system, a single machine functions as both a pump and a turbine, rotating in both directions based on the energy requirement. This flexibility makes PSPs an efficient energy storage solution, helping balance renewable energy fluctuations.
Pumped Storage Projects (PSPs) are categorized into three types:
1. On-stream Pumped Storage Projects have both reservoirs located on a perennial river or stream.
2. Off-stream Pumped Storage Projects (Open Loop) have one reservoir situated on a perennial river or stream, while the other is positioned separately.
3. Off-stream Pumped Storage Projects (Closed Loop) are systems where both reservoirs are independent of any river or stream, relying solely on stored water for operation.
4.1 Potential of Pumped Storage Projects (Water Batteries) in India
IIndia has a total installed capacity of 4,745.60 MW for Pumped Storage Projects (PSPs). However, 1,440 MW remains non-operational in pumping mode due to challenges related to lower reservoir construction and machine vibrations.
The country holds immense potential for expanding its PSP capacity. So far, 111 PSPs with a combined capacity of 122.77 GW have been identified, with many more projects under consideration. Developing these projects requires strategic planning, site selection, economic feasibility, government backing, and significant investments from both the public and private sectors.
As per the National Electricity Plan, India will require 73.9 GW of storage capacity by 2031-32, with 26.6 GW expected to come from PSPs and 47.2 GW from Battery Energy Storage Systems (BESS).
Currently, three PSP projects with a total capacity of 2,700 MW are under construction. Additionally, around 43 projects with a capacity of 55,035 MW have been approved by the Central Electricity Authority (CEA) or are in the survey and investigation phase.
Several public sector undertakings (CPSUs) and private developers are actively planning the development of more PSPs, reinforcing India’s commitment to sustainable energy storage solutions.
4.2 Government support for developing the hydro energy sector, including PSPs.
Hydropower development is a capital-intensive process that demands substantial investment and long project timelines. These projects are typically situated in remote regions, far from major power demand centres, where infrastructure remains underdeveloped.
Developers must allocate significant funds and time to establish the necessary infrastructure, often causing delays in project completion. Consequently, power generation costs rise, leading to higher tariffs, which ultimately place a financial burden on consumers.
The Ministry of Power (MoP), Government of India, has introduced several sustainable initiatives to promote the development of hydro projects, including Pumped Storage Projects (PSPs):
a.) Large hydro projects with a capacity exceeding 25 MW are now classified as renewable energy sources and enjoy the same benefits as small hydropower projects.
b.) The Hydro Purchase Obligation (HPO) is a distinct category under the Non-Solar Renewable Purchase Obligation (RPO). It applies to all large hydro projects commissioned after March 2019, including their untied capacity (without a Power Purchase Agreement).
c.) Tariff rationalization measures have been implemented to lower hydropower tariffs. These include extending the project lifespan to 40 years, increasing the debt repayment period to 18 years, and introducing a 2% annual tariff escalation.
d.) Budgetary support will be provided for Flood Moderation/Storage Hydroelectric Projects (HEPs) through grants from the Ministry of Power. The flood moderation component will be assessed by technical agencies like the Central Water Commission (CWC) following specific guidelines.
e.) The Ministry of Power will offer budgetary support for developing essential infrastructure for hydropower projects, including roads and bridges. Grants for these infrastructure projects will be provided within specified limits, as outlined in the guidelines.
1. a)A grant of ₹1.5 crore per MW will be provided for hydropower projects with a capacity of up to 200 MW.
2. b) A grant of ₹1.0 crore per MW will be provided for hydropower projects with a capacity exceeding 200 MW.
F.) On July 22, 2022, the Government of India issued an order defining the Energy Storage Obligation (ESO), mandating that distribution companies maintain adequate energy storage capacity to ensure grid stability.
G.) To promote the growth of Pumped Storage Projects (PSPs), the Government has waived ISTS charges for all PSPs that commence construction by June 30, 2025. Beyond this date, ISTS charges will apply to PSPs as per the following schedule:
| Sl no | Award of construction work | ISTS Charges |
|---|---|---|
| 1 | 01.07.2025 to 30.06.2026 | 25% of applicable ISTS charges |
| 2 | 01.07.2026 to 30.06.2027 | 50% of applicable ISTS charges |
| 3 | 01.07.2027 to 30.06.2028 | 75% of applicable charges |
| 4 | From 01.07.2028 | 100% of applicable charges |
a.) The Central Electricity Authority (CEA) has streamlined the approval process for Pumped Storage Projects (PSPs), reducing the timeline from 150 days to a much faster timeframe.
- The approval process for projects under Tariff-Based Competitive Bidding (TBCB) and those developed as Independent Renewable Energy Projects (IREP), merchant, and captive plants has been accelerated to just 50 days.
- The approval process for other Pumped Storage Projects (PSPs) allocated through nomination or bidding has been shortened to 90 days.
- A “Single Window Clearance Cell” is being set up within the Central Electricity Authority (CEA) to expedite the approval process for Detailed Project Reports (DPRs) of Hydro Electric Projects (HEPs) and Pumped Storage Projects (PSPs).
The Government of India has implemented safeguards and incentives to promote the development of Pumped Storage Projects (PSPs) across the country.
5.0 Technologies in enhancing the efficiency of hydro energy production.
Hydro turbines generally operate with an efficiency range of 90-93%, while hydro generators achieve an impressive 99% efficiency, and transformers operate at around 99.5% efficiency. These high efficiencies align with the latest advancements in the electrical sector.
To enhance hydro turbine efficiency, advanced tools like Computational Fluid Dynamics (CFD) and Finite Element Method (FEM) are utilized to optimize hydraulic flow paths, turbines, and their operational range. Additionally, hydraulic characteristics are analyzed using specialized software to minimize losses, with model testing validating these improvements.
One key area for efficiency enhancement is reducing auxiliary power consumption. The current standard permits 1.2% auxiliary power consumption in underground projects and 1.0% in surface projects. However, this can be further minimized by incorporating premium efficiency motors (IE3, IE4), which increase efficiency by about 1% compared to energy-efficient motors. Additionally, selecting the right motors, optimizing pumps for duty points, and using LED lighting for both indoor and outdoor power stations significantly reduce auxiliary power consumption.
Voltage Variable Frequency (VVVF) drives in pumps further enhance system efficiency, especially when operating across a wide range. For Pumped Storage Projects (PSPs), the use of starting equipment (SFC) contributes to auxiliary power consumption, but employing a back-to-back starting method can effectively reduce power usage during startup.
Furthermore, variable-speed hydro generators significantly boost efficiency by maintaining optimal operational points, particularly when head variation is substantial, ensuring pumps function within a wide operational range.
To sustain high efficiency, hard coatings such as HP/HVOF (High Pressure/High-Velocity Oxygen Fuel) on turbine water paths help mitigate silt erosion damage, preserving long-term performance.
Conclusion
energy transition and seamlessly integrating green energy into the national grid. As the country works towards its ambitious renewable energy targets, the need for reliable and efficient energy storage solutions becomes even more critical. PSPs act as a buffer, storing excess renewable energy during low-demand periods and releasing it when demand surges or when renewable sources like solar and wind are not generating sufficient power.
By enhancing grid stability, ensuring a reliable power supply, and supporting intermittent renewable energy sources, water batteries significantly contribute to India’s commitment to reducing its carbon footprint. With the government’s continuous efforts to improve infrastructure, incentivize investments, and streamline approvals, the potential for PSPs to become a cornerstone of India’s green energy future is immense.
As technology advances and environmental policies strengthen, water batteries will remain a key component of India’s path toward a cleaner, more sustainable energy landscape.
