Which one of the following projects of the NHPC (National Hydroelectric Power Corporation) has the largest power generation capacity (installed) ?

1. India's Energy Mix: The Role of Hydroelectricity (basic)

Welcome to your first step in understanding India's infrastructure! To understand the Energy Mix, we must look at where India gets its power. Hydroelectricity—the process of generating electricity by using the force of falling or flowing water—is one of India's oldest and most reliable sources of power. Unlike coal, it is renewable and produces no direct greenhouse gas emissions during operation. Historically, India relied heavily on rivers for power, but as our demand skyrocketed, the "mix" of energy sources shifted significantly to meet the scale of our growing economy.

In the current Indian scenario, electricity generation is dominated by Thermal energy (primarily coal), which accounts for roughly 63% of installed capacity. Hydroelectricity follows as a significant secondary pillar, contributing about 12% of the total capacity Indian Economy, Nitin Singhania (ed 2nd 2021-22), Infrastructure, p.448. While its percentage share has seen a relative decline compared to the rapid rise of Solar and Wind energy, Hydro remains indispensable for grid stability. Because hydro plants can be started and stopped quickly, they are used as "peaking" power plants to balance the grid when demand suddenly spikes or when solar/wind generation drops.

Source Type	Approx. Share (%)	Primary Characteristic
Thermal	~63%	Base load; high carbon footprint.
Renewables (Solar/Wind)	~23%	Intermittent; fastest growing sector.
Hydroelectricity	~12%	Renewable; excellent for peak demand.
Nuclear	~2%	Clean base load; limited by fuel/technology.

Developing hydroelectric projects in India isn't without hurdles. Unlike a solar park, a large dam significantly alters the local geography. Major challenges include land acquisition issues, the displacement of local communities, and ecological concerns regarding river ecosystems. Furthermore, because many of India's major rivers flow through multiple states, inter-state water disputes often delay project approvals and construction Indian Economy, Nitin Singhania (ed 2nd 2021-22), Infrastructure, p.448. Despite this, India aims to reach a 500 GW non-fossil fuel capacity by 2030, ensuring that hydro remains a central part of our transition toward a "Net Zero" future Environment, Shankar IAS Academy (ed 10th), Renewable Energy, p.287.

Sources: Indian Economy, Nitin Singhania (ed 2nd 2021-22), Infrastructure, p.448; Environment, Shankar IAS Academy (ed 10th), Renewable Energy, p.287

2. Types of Hydroelectric Projects: Storage vs Run-of-the-River (intermediate)

Concept: Types of Hydroelectric Projects: Storage vs Run-of-the-River

3. National Hydroelectric Power Corporation (NHPC) and PSUs (basic)

To understand India's energy infrastructure, we must look at the giants that build it. The National Hydroelectric Power Corporation (NHPC), established in 1975, is India's premier organization for hydroelectric power generation. As a Central Public Sector Enterprise (CPSE), it plays a critical role in the country's transition to renewable energy. Hydroelectric projects are unique because they are often located in challenging Himalayan terrains and serve as "peaking power plants" — they can start up quickly to meet sudden surges in electricity demand.

The government grants different levels of autonomy to these PSUs based on their financial health and size. This hierarchy determines how much the company can invest without seeking prior government approval. According to the criteria for Maharatna status, a company must already hold Navratna status, be listed on the Indian stock exchange, and maintain an average annual net profit of more than ₹5,000 crore over the last three years Indian Economy, Nitin Singhania (ed 2nd 2021-22), Indian Industry, p.383. NHPC has historically operated as a high-performing Navratna (and more recently upgraded), reflecting its massive scale and financial stability.

NHPC’s footprint spans across the country, with iconic projects like Salal in Jammu & Kashmir (approx. 690 MW), Chamera-I in Himachal Pradesh (540 MW), and Loktak in Manipur (105 MW). These projects are not just engineering marvels but are essential for regional development and grid stability Geography of India, Majid Husain (McGrawHill 9th ed.), Energy Resources, p.22. While some projects like Subansiri Lower are massive undertakings still under construction, the existing portfolio showcases NHPC's ability to harness water power across diverse geographies.

PSU Status	Investment Autonomy (General Rule)	Key Criterion (Net Profit)
Maharatna	Up to ₹5,000 crore in a single project	> ₹5,000 Cr (Avg. over 3 years)
Navratna	Up to ₹1,000 crore or 15% of net worth	Must be a Miniratna Category-I

Sources: Indian Economy, Nitin Singhania (ed 2nd 2021-22), Indian Industry, p.383; Geography of India, Majid Husain (McGrawHill 9th ed.), Energy Resources, p.22

4. Hydropower Potential in the Himalayan River Basins (intermediate)

The Himalayan region is often referred to as the 'Powerhouse of India' because its unique physiography provides the two essential ingredients for hydropower: high head (vertical drop) and perennial water flow. The rivers here are fed by both monsoon rains and the melting of massive glaciers, such as those in the Karakoram and near Mt. Kailash Geography of India, Majid Husain, Drainage System, p. 8. This ensures a steady discharge even during the lean summer months. The steep gradients and narrow gorges of the Indus, Ganga, and Brahmaputra basins allow for the construction of high dams and 'run-of-the-river' projects that can generate thousands of megawatts of electricity. However, this potential is governed by complex geographical and legal frameworks. In the Indus Basin, which includes the Jhelum, Chenab, Ravi, Beas, and Satluj, India's development is guided by the Indus Waters Treaty (1960). Under this treaty, India is permitted to utilize only 20% of the total water discharge of the Indus system Contemporary India-I, NCERT Class IX, Drainage, p. 18. Despite these limits, India has developed significant infrastructure on these 'Western Rivers,' such as the Salal Power Station on the Chenab in Jammu & Kashmir (approx. 690-750 MW) and the Chamera projects in Himachal Pradesh Geography of India, Majid Husain, Energy Resources, p. 22. Moving eastward, the Brahmaputra Basin holds the highest theoretical hydropower potential in India, particularly in Arunachal Pradesh, due to the river's massive volume and the sharp descent it takes as it enters India. While projects like the Subansiri Lower are massive undertakings, the region faces challenges like high seismicity and the need for international cooperation, as seen in the proposed Brahmaputra-Ganga Link Canal which requires concurrence from Bangladesh Geography of India, Majid Husain, Drainage System, p. 43.

River Basin	Key Characteristics	Major Projects
Indus Basin	Regulated by IWT (1960); high head in J&K and HP.	Salal (Chenab), Chamera (Ravi), Baira-Siul
Brahmaputra Basin	Highest potential; faces high siltation and seismic risks.	Subansiri Lower, Loktak (Manipur)
Ganga Basin	Deep gorges in Uttarakhand; environmental sensitivity.	Teesta-V, Tehri

Sources: Geography of India, Majid Husain, The Drainage System of India, p.8, 43; Geography of India, Majid Husain, Energy Resources, p.22; Contemporary India-I, NCERT Class IX, Drainage, p.18

5. Trans-boundary Water Issues and Indus Waters Treaty (exam-level)

When we discuss trans-boundary water issues in the Indian context, we are looking at how natural river systems are carved up by political borders, leading to a tug-of-war between Upper Riparian states (where the river begins) and Lower Riparian states (where it flows out). The most significant example is the Indus Waters Treaty (IWT) of 1960. Before this, India and Pakistan were locked in a fierce dispute over the Indus basin waters following Partition Contemporary World Politics, Contemporary South Asia, p.39. After nearly a decade of negotiations mediated by the World Bank (then the IBRD), the treaty was signed in Karachi on September 19, 1960, by PM Jawaharlal Nehru and President Ayub Khan A Brief History of Modern India, Developments under Nehru’s Leadership, p.650.

The IWT is unique because it did not just share the water of each river; it divided the rivers themselves between the two nations. This division allowed both countries to plan their energy and irrigation infrastructure with a degree of certainty. To ensure smooth implementation and handle disputes, the Permanent Indus Commission was established, featuring commissioners from both sides Geography of India, The Drainage System of India, p.39.

River Category	Rivers Included	Primary Rights
Eastern Rivers	Ravi, Beas, Satluj	Exclusive rights given to India.
Western Rivers	Indus, Jhelum, Chenab	Allocated to Pakistan (India has limited use for domestic, non-consumptive, and specific agricultural/hydroelectric purposes).

Beyond the Indus, India manages water relations with other neighbors, such as Bangladesh. A prime example is the proposed Brahmaputra-Ganga Link Canal, intended to divert water from the Brahmaputra to the Ganga at Farakka during lean months to benefit both nations. However, such projects often stall due to the need for international concurrence and the high financial costs involved Geography of India, The Drainage System of India, p.43. These international complexities are mirrored domestically by inter-state disputes over rivers like the Narmada and Godavari, which India seeks to resolve through the principle of equitable apportionment Geography of India, The Drainage System of India, p.38.

Sources: Contemporary World Politics, Contemporary South Asia, p.39; Geography of India, The Drainage System of India, p.38, 39, 43; A Brief History of Modern India, Developments under Nehru’s Leadership (1947-64), p.650

6. Comparing Key NHPC Projects and Installed Capacities (exam-level)

To master the landscape of India's energy infrastructure, we must look at the National Hydroelectric Power Corporation (NHPC), the premier organization for hydropower development. While India has vast potential, the actual installed capacity varies significantly across projects based on the river's discharge and the available 'head' (the height the water falls). A critical skill for the UPSC exam is being able to categorize these projects by their geographic location, the river they harness, and their relative power output. Among the legacy projects of the NHPC, the Salal Power Station in Jammu & Kashmir is a cornerstone. Constructed across the Chenab River in the Reasi district, it has an installed capacity often cited between 690 MW and 750 MW Geography of India, Majid Husain, Energy Resources, p.22. It was a pioneering project in the Himalayas, inaugurated in 1986 to supply power to the Northern Grid, including Punjab, Haryana, and Delhi. In contrast, other early projects like Baira-Siul in Himachal Pradesh (180 MW) and Loktak in Manipur (105 MW) were smaller in scale but strategically vital for their respective regions. When comparing capacities, it is helpful to look at the 'Chamera complex' on the Ravi River in Himachal Pradesh. Chamera-I is the largest in that specific cluster with a capacity of 540 MW. While NHPC is currently developing massive projects like the Subansiri Lower (2000 MW), understanding the hierarchy of these established stations is essential for geography and infrastructure mapping.

Project Name	River / State	Approx. Capacity
Salal	Chenab (J&K)	690 - 750 MW
Chamera-I	Ravi (HP)	540 MW
Baira-Siul	Baira/Siul/Tanera (HP)	180 MW
Loktak	Leimatak (Manipur)	105 MW

Sources: Geography of India, Majid Husain, Energy Resources, p.22; Geography of India, Majid Husain, Physiography, p.29

7. Solving the Original PYQ (exam-level)

This question tests your ability to bridge the gap between knowing the geographical locations of dams and their industrial output. Having just studied the distribution of energy resources, you’ll recognize that NHPC manages key hydroelectric assets primarily across the Himalayan belt. To solve this, you must move beyond just identifying river basins and start categorizing projects by their installed capacity, a common metric used to rank the significance of power stations in texts like the Geography of India by Majid Husain.

To arrive at the correct answer, (D) Salal, you must evaluate the relative scale of these projects through comparative elimination. The Salal Power Station, located on the Chenab River in Jammu & Kashmir, is a major installation with a capacity of 690 MW (sometimes cited up to 750 MW). While Chamera-I is a significant project at 540 MW, it remains second to Salal in this specific list. The reasoning here is a matter of scale: Salal was one of the earliest major NHPC projects designed to meet heavy regional demand, whereas others like Baira-Siul (180 MW) and Loktak (105 MW) serve more localized or niche grid requirements.

UPSC often sets distractor traps by including options like Loktak, which is highly famous due to its unique ecology (Phumdis and Keibul Lamjao National Park). Students often mistakenly equate "fame" or "ecological importance" with "largest power capacity." Similarly, Chamera-I is a common pitfall because it is a very large project in Himachal Pradesh, but it lacks the overall volume of the Salal units. Remember: always differentiate between a project's environmental notoriety and its technical output when tackling energy-related PYQs.