Table of Contents
India, the world’s fifth-largest economy, is set to achieve a 7% GDP growth by 2024. The energy sector plays a key role in India’s economic progress, which has undergone remarkable changes.
1.0. Background
India is one of the fastest-growing nations globally, undergoing major transformations over the past few decades. It is the fifth-largest economy in the world, with its GDP projected to grow by nearly 7% in 2024, driven by advancements in infrastructure, industries, and improved living standards. Electricity is vital in driving economic growth and is a key requirement for industrial, rural, and agricultural development.
India has been a pioneer in hydropower generation in Asia, with a history spanning more than 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 capacity of 4.5 MW. After independence, hydropower development became a priority for the Indian government. Its share in India’s energy mix reached over 45% during the 1960s but has declined to just above 11% in 2023.
Countries like Norway, Brazil, and Venezuela depend significantly on hydropower globally. India is rich in hydropower potential, estimated at around 148,700 MW. However, only 51.8 GW has been harnessed so far through small and large hydropower projects. The slower development of hydropower since the 1970s can be attributed to challenges such as public opposition to dam projects, land acquisition disputes, resettlement issues, funding limitations, lack of advanced technology, and geological challenges.
To accelerate economic growth, India shifted its focus to thermal power plants, particularly coal-based ones, which now account for about 56% of the total installed capacity and meet 75% of the country’s electricity needs.
However, coal-fired power plants are a major contributor to greenhouse gas emissions. A 2020 study revealed that the electricity and heat sector is responsible for around 35% of India’s total emissions, with over 90% coming from coal-fired plants, primarily in CO2.
2.0. Power growth trajectory in India
India has traditionally relied on coal and oil as its main sources of electricity generation, leading to high CO2 emissions. While India ranks third globally in carbon emissions, its per capita CO2 emissions remain among the lowest in the world. To address energy security concerns and uphold its commitment to a Low Carbon Growth Strategy, the Indian government is focusing on the sustainable development of the power sector, with a strong emphasis on renewable energy sources, including hydropower.
India’s per capita electricity consumption currently stands at 1,255 kWh—just one-third of the global average and only one-tenth of the per capita consumption in the United States. With its large population and ambitious growth targets, India’s energy demand is expected to rise faster than any other country in the coming decades.
India aims to achieve net-zero emissions by 2070 by meeting most of its growing energy needs with low-carbon sources. India has outlined a clear mission to transition from fossil fuels to renewable energy as part of its commitment to combating climate change. This effort aligns with its global responsibility to reduce the impact of climate change.
India has adopted the Panchamrit strategy to guide this transition, a five-point plan to drive its energy transformation and achieve a sustainable energy future.
- India aims to boost its renewable energy capacity to 500 GW by 2030.
- India plans to reduce its carbon emission intensity by 45% of GDP by 2030.
- By 2030, 50% of India’s energy will come from non-fossil fuel sources.
- India aims to cut carbon emissions by one billion tonnes between now and 2030, compared to 2005.
- India is committed to achieving net-zero carbon emissions by 2070.
The country has adopted a new economic development model focused on clean energy, which will reduce the carbon footprint during growth.
2.1. Growth of Renewable Energy
In line with its commitment to reducing carbon emissions, India has steadily increased the share of renewable energy in its energy mix. The generation of variable renewable energy (solar and wind) has grown by 333%, from 27 GW in 2015 to 116 GW in 2023. According to the CEA National Electricity Plan, this capacity is expected to reach around 486 GW by 2031-32.
The growth of renewable energy from 2015 to 2023 is shown in Figure 1.0 (Source: CEA).
3.0. Requirement of Energy Storage System (Batteries)
According to the INDC, India aims to achieve 500 GW of renewable energy, with 420 GW coming from Variable Renewable Energy (VRE) sources like wind and solar. These sources are intermittent, meaning their generation depends on the time of day, seasons, and weather conditions. As India adds more VRE to the grid, the power system will experience significant changes. By 2030 and beyond, the grid will largely depend on VRE generation.
In the past, power generation was fully controllable and adjusted to match the demand. However, VRE generation is not fully controllable, as its output fluctuates due to weather changes. This creates uncertainty, leading to periods when there is too much power on the grid, causing a mismatch between supply and demand. Surplus power must either be consumed or stored, or VRE generation will be reduced, a process known as curtailment. Some southern states in India already face curtailment when VRE generation exceeds 20% of total energy capacity.
As VRE generation grows by 2030, energy storage becomes critical to prevent more curtailment. Pumped Storage Hydro Projects (PSP), known as water batteries, are the most mature and domestically available among various energy storage technologies. PSP technology is ideal for large-scale grid applications due to its proven technology, long lifespan, cost-effectiveness, and minimal environmental impact. PSPs use mainly domestic technologies and materials, with most of their electrical and mechanical components made in India, unlike chemical batteries, which rely on imports. PSPs are clean, green, and safe and do not produce harmful by-products or pose disposal issues.
4.0 Water Battery (Pumped Storage Project) concept.
A Pumped Storage Project (PSP) has two reservoirs: an upper reservoir at a higher elevation and a lower reservoir at a lower elevation, connected by a Tail Race Tunnel. The other civil components are similar to those of a regular hydroelectric project. Water is pumped from the lower reservoir to the upper reservoir, storing it as potential energy. When energy is needed, the water is released from the upper reservoir and flows down, using gravity to turn a turbine and generate electricity. In a PSP, a single machine acts as the pump and the turbine, rotating in both directions as needed.
Pumped Storage Projects are classified into three types:
1. On-stream Pumped Storage Projects are where both reservoirs are situated on a perennial river or stream.
2. Off-stream Pumped Storage Projects (Open Loop) are where one of the reservoirs is located on a perennial river or stream.
3. Off-stream Pumped Storage Projects (Closed Loop) are where neither of the reservoirs is located on a river or stream.
4.1 Potential of Pumped Storage Projects (Water Batteries) in India
India has a total installed capacity of 4,745.60 MW for Pumped Storage Projects (PSPs). However, 1,440 MW is currently not operational in pumping mode due to problems with the lower reservoir construction and machine vibrations.
India has significant potential to develop more PSPs in the future. So far, 111 PSPs with a combined capacity of 122.77 GW have been identified, with many more projects under consideration. Developing these projects will require careful planning, site selection, economic strategies, government support, and substantial investments from both public and private sectors. According to the National Electricity Plan, about 73.9 GW of storage capacity will be needed by 2031-32, with 26.6 GW coming 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. In comparison, approximately 43 projects with a capacity of 55,035 MW have either been approved by the Central Electricity Authority (CEA) or are in the survey and investigation stage. Various public sector undertakings (CPSUs) and private developers plan to develop many more PSPs.
4.2 Government support for developing the hydro energy sector, including PSPs.
Hydropower development is a capital-intensive process that requires significant investment and time. These projects are often located in remote areas far from the main power demand centers, where infrastructure is underdeveloped. Developers must spend considerable funds and time building the necessary infrastructure, which can delay the completion of the projects. As a result, power generation costs increase, leading to higher tariffs burdening consumers.
The Ministry of Power (MOP), Government of India, has launched several sustainable initiatives to support the development of hydro projects in the country, including Pumped Storage Projects (PSPs). Some of these initiatives are as follows:
a. Large hydro projects with a capacity greater than 25 MW are recognized as renewable energy sources and are eligible for the same benefits as small hydropower projects.
b. The Hydro Purchase Obligation (HPO) is a separate category under the Non-Solar Renewable Purchase Obligation (RPO). It applies to all large hydro projects commissioned after March 2019 and their untied capacity (without a Power Purchase Agreement).
c. Tariff rationalization measures have been introduced to reduce hydropower tariffs. These include extending the project life of hydro projects to 40 years, increasing the debt repayment period to 18 years, and introducing a 2% annual increase in tariffs.
d. Budgetary support will be provided for Flood Moderation/Storage Hydroelectric Projects (HEPs) through grants from the Ministry of Power. The value of the flood moderation component will be determined by technical agencies, such as the Central Water Commission (CWC), based on specific guidelines.
e. The Ministry of Power will provide budgetary support for constructing essential infrastructure for hydropower projects, such as roads and bridges. The grant for these roads and bridges will be provided within specific limits, which will be outlined accordingly.
1. a) A grant of Rs. 1.5 crore per MW will be provided for hydropower projects with up to 200 MW capacity.
2. b) A grant of Rs. 1.0 crore per MW will be provided for hydropower projects with a capacity above 200 MW.
F. On July 22, 2022, the Government of India issued an order outlining the Energy Storage Obligation. This requires distribution companies to have the necessary energy storage capacities to support the grid.
G. To encourage the development of Pumped Storage Projects (PSPs), the Government has waived ISTS charges for all PSPs where construction begins by June 30, 2025. After this date, ISTS charges will apply to PSPs based on 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 shortened the approval process for Pumped Storage Projects (PSPs) from 150 days to a quicker timeframe.
- The approval process for projects awarded under the Tariff-Based Competitive Bidding (TBCB), as well as projects developed as Independent Renewable Energy Projects (IREP), merchant, and captive plants, has been reduced to 50 days.
- The approval process for other Pumped Storage Projects (PSPs) allocated on a nomination basis or through the bidding process has been reduced to 90 days.
- A “Single Window Clearance Cell” is being established in the Central Electricity Authority (CEA) to speed up the approval process for Detailed Project Reports (DPRs) of Hydro Electric Projects (HEPs) and Pumped Storage Projects (PSPs).
H. The process for obtaining environmental clearances for Pumped Storage Projects (PSPs) is simplified to make it more efficient.
A. Standalone Pumped Storage Projects (PSPs) are now classified separately from River Valley and Hydroelectric Projects.
B. Pumped Storage Projects (PSPs), including off-stream closed loop projects, will be evaluated based on specific guidelines issued by the Central Government. These include data collection for one or two seasons for off-stream closed-loop and off-stream open-loop projects.
C. Pumped Storage Projects (PSPs) that meet specific criteria will be classified as B2 category, meaning they do not require an Environmental Impact Assessment (EIA) or Environmental Management Plan (EMP), regardless of their power generation capacity.
I. The guidelines for developing Pumped Storage Projects (PSPs) outline a clear and transparent process for allocating project sites, as detailed below.
I. Central public sector undertakings (CPSUs) and state public sector undertakings (state PSUs) will be allocated project sites on a nomination basis.
II. The project sites will be allocated through a competitive bidding process.
iii. The project sites will be allocated through Tariff-Based Competitive Bidding (TBCB).
iv. Self-identified off-stream Pumped Storage Projects are those developers identify and propose independently, without government or external direction.
I. According to the guidelines, a project allocation can be canceled if construction does not begin within 2 years from the allotted date.
J. Monetizing Ancillary Services: The relevant commission ensures that ancillary services, such as spinning reserve, reactive support, black start, peaking supply, ramping support, and quick start-up or shutdown, are properly compensated.
K. The relevant commission will set peak and off-peak tariffs to provide clear pricing signals for peak and baseload power generation.
L. Pumped Storage Projects (PSPs) will be allowed to participate in all market segments of the power exchange, including the high-price segment of the Day Ahead Market (HP-DAM).
M. When Pumped Storage Projects (PSPs) operate as conventional hydro (without pumping power), 80% of the generated power will be provided to the home state at a rate set by the Central Electricity Regulatory Commission (CERC).
N. Idle contracted capacity can be transferred to other interested parties to ensure it is not left unused. The benefits from this transfer will be shared equally (50:50) with the original beneficiary.
The Government of India has introduced safeguards and incentives to encourage the development of Pumped Storage Projects in the country.
5.0 Technologies in enhancing the efficiency of hydroenergy production.
Hydro turbines typically have an efficiency range of 90-93%, while hydro generators are highly efficient at 99%, and transformers operate at around 99.5%. These high efficiencies align with the latest advancements in the electrical sector.
To improve hydro turbine efficiency, tools like CFD (Computational Fluid Dynamics) and FEM (Finite Element Method) are used to optimize the hydraulic flow path, turbines, and their operational range. Hydraulic characteristics are also analyzed with software to minimize losses, and model testing validates these improvements.
One area for efficiency improvement is reducing auxiliary power consumption. The current standard allows for 1.2% auxiliary power consumption in underground projects and 1.0% in surface projects. This can be reduced further by using premium efficiency motors (IE3, IE4), which boost efficiency by about 1% over energy-efficient motors. Proper motor selection and pumps designed for optimal duty points enhance system efficiency. Additionally, using LED lights for indoor and outdoor power station lighting has effectively lowered auxiliary power use.
Voltage Variable Frequency (VVVF) drives in pumps increase system efficiency, especially when operating over a wide range. For pumped storage projects (PSPs), introducing starting equipment (SFC) adds to auxiliary consumption. However, using back-to-back starting methods can reduce auxiliary power use during startup.
Variable-speed hydro generators improve efficiency by maintaining the best operational point when head variation is significant, especially when pumps require a wide operational range.
Hard coatings like HP/HVOF (High Pressure/High-Velocity Oxygen Fuel) on turbine water paths help maintain high efficiency by reducing damage from silt erosion.
Conclusion
Water batteries, specifically pumped storage systems (PSPs), are critical in accelerating India’s energy transition and integrating green energy into the national grid. As the country strives to meet ambitious renewable energy targets, reliable and efficient energy storage solutions become even more vital. PSPs provide a much-needed buffer, storing excess renewable energy during low demand and releasing it when the demand spikes or when renewable sources like solar and wind are not generating enough power.
By enhancing grid stability, ensuring reliable power supply, and supporting the growth of intermittent renewable energy sources, water batteries contribute significantly to India’s commitment to reducing its carbon footprint. With the government’s ongoing efforts to improve infrastructure, incentivize investments, and streamline the approval process, 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 continue to be essential to India’s journey toward a cleaner, more sustainable energy landscape.
FAQs
Q1: What are water batteries?
Ans: Water batteries, particularly pumped storage systems (PSPs), are large-scale energy storage solutions that store excess electricity using water. When electricity demand is low, excess power is used to pump water from a lower reservoir to an upper one. The water is released during high-demand periods, flowing downhill to generate electricity. These systems are energy storage, ensuring a reliable and consistent power supply.
Q2: How do water batteries help integrate green energy in India?
Ans: Water batteries help integrate green energy by storing excess electricity from renewable sources like solar and wind. Since these energy sources are intermittent, they do not always produce power when needed. Water batteries store surplus energy during high renewable output and release it during peak demand or when renewable generation is low, thus helping balance the grid and stabilize power supply.
Q3: What is the role of water batteries in India’s energy transition?
Ans: Water batteries play a crucial role in India’s energy transition by facilitating the shift from fossil fuel-based energy to renewable energy. They ensure that renewable energy sources, such as solar and wind, can be efficiently integrated into the grid, improving energy security and reducing reliance on coal and other non-renewable sources. Water batteries help manage the variability of renewables, making the grid more stable and reliable.
Q4: Why are pumped storage systems (PSPs) important for India’s grid stability?
Ans: PSPs are important for grid stability because they store large amounts of energy and release it when needed. Since renewable energy sources like wind and solar are not consistently available, PSPs help fill the gap when demand is high or renewable generation is low. This ability to store and dispatch power on demand ensures a stable and reliable grid, which is vital as India increases its renewable energy capacity.
Q5: What are the environmental benefits of water batteries in India?
Ans: Water batteries, like PSPs, contribute to environmental sustainability by enabling greater use of renewable energy and reducing the need for fossil fuel-based power plants. They help lower carbon emissions by storing excess renewable energy and reducing dependence on coal or gas-fired plants for backup power. Additionally, by improving the efficiency of the grid, PSPs minimize energy losses, further reducing the environmental impact.
Q6: How do water batteries support India’s renewable energy targets?
Ans: Water batteries support India’s renewable energy targets by addressing one of the key challenges of renewable energy integration: storage. As India aims to meet its ambitious renewable energy goals, water batteries provide a reliable solution for storing excess energy generated by solar and wind power, allowing the grid to balance supply and demand. This helps maximize the use of renewable energy and accelerates the transition to a clean energy future.
Q7: What challenges do water batteries face in India’s energy transition?
Ans: While water batteries offer many benefits, they face challenges in India’s energy transition, including high capital costs, long development timelines, and the need for suitable locations with the right topography for building reservoirs. Additionally, the construction of such projects requires significant investment in infrastructure and environmental assessments, which can slow the pace of implementation. However, these challenges are being addressed through government incentives and policy reforms.
Q8: How does India plan to scale up water battery projects?
Ans: India plans to scale up water battery projects through policy support, financial incentives, and streamlined approval processes. The government focuses on reducing development timelines, offering budgetary support for infrastructure, and encouraging private investments in pumped storage systems. Additionally, efforts are being made to identify suitable sites for these projects to enhance India’s energy storage capacity and meet future demand.
Q9: Can water batteries contribute to energy independence for India?
Ans: Yes, water batteries can contribute to India’s energy independence by reducing its reliance on imported fossil fuels. By facilitating the use of domestic renewable energy sources, water batteries help ensure that India can generate and store its own energy. This reduces the need for expensive coal and oil imports, helping the country move towards greater energy self-sufficiency.
Q10: How do water batteries impact power tariffs in India?
Ans: Water batteries help reduce power tariffs by stabilizing the grid and ensuring the efficient use of renewable energy. They can also lower the need for backup power from more expensive fossil fuel plants by providing a cost-effective solution for balancing supply and demand. This can result in lower consumer electricity costs as renewable energy becomes a larger portion of India’s energy mix.
