Thermal Power in India

Timeline

• 7 November 1975: the National Thermal Power Corporation (NTPC) is founded.
• 1987: Vindhyachal commissions its first unit.
• 2015: the government mandates FGD systems on coal plants to cut sulphur dioxide.
• 20 March 2025: India crosses 1 billion tonnes of annual coal production for the first time, in FY 2024-25.
• Today: coal supplies roughly 70% of India’s electricity.

The basics

• Thermal power, mostly coal-based, is India’s single largest source of electricity.
• NTPC is India’s largest power generator and runs 27 coal-based stations.
• The Vindhyachal Thermal Power Station, in Singrauli district, Madhya Pradesh, is India’s largest thermal plant.
• Fly ash and emissions of sulphur dioxide and oxides of nitrogen are the main pollution concerns.

Where the coal comes from

• India holds the world’s fifth-largest coal reserves, an estimated 401 billion tonnes.
• It is the world’s second-largest coal producer, behind only China.
• Coal India Limited supplies roughly three-quarters of the nation’s coal.

Major plants

• Vindhyachal has 4,760 MW of coal power, plus 15 MW of solar and 8 MW of hydropower.
• That unusual mix puts thermal, hydro and solar on one site.
• Mundra Thermal Power Station, owned by Adani Power, is the second-largest, at 4,620 MW.
• The Sasan Ultra Mega Power Plant, also in Madhya Pradesh, has roughly 3,960 MW.
• NTPC calls itself the power behind “every fourth light in India”.

Coal ash and coal quality

• Coal ash contains heavy metals: arsenic, lead and mercury.
• That is why its disposal and reuse are tightly regulated.
• See Fly Ash.
• Indian coal, mostly from Gondwana-era deposits, has high ash content, often 30–50% or more.
• Imported coal from Australia or Indonesia is closer to 10–20% ash.

How a plant works

• Pulverised coal burns in a boiler and heats water into high-pressure steam.
• The steam spins a turbine, and the turbine’s shaft turns a generator.
• After the turbine, the steam must be cooled back into water and returned to the boiler.
• That cooling step is why thermal plants need huge, steady volumes of water.

Scale cuts both ways

• A plant like Vindhyachal makes huge volumes of both electricity and fly ash.
• India plans to add around 97,000 MW more coal and lignite capacity by 2034-35.
• So India is not simply replacing coal. It is growing both coal and renewables to meet demand.

The FGD mandate

• The FGD mandate was issued in 2015, with an original 2017 deadline.
• The deadline has been pushed back repeatedly.
• Most recently it moved to December 2026 for most plants and December 2027 for plants nearing retirement.
• Compliance remains low nationally.
• Vindhyachal is an exception NTPC highlights: all 13 coal units are on track for FGD by mid-2026.

Where new money is going

• As of end-June 2026, NTPC’s under-construction renewable capacity (16.4 GW) passed its under-construction coal capacity (15.7 GW) for the first time.
• This does not mean coal is shrinking. Existing coal capacity keeps growing.
• NTPC still targets 26–27 GW of new coal capacity by 2032, alongside 60 GW of renewables.
• It aims for roughly 149 GW total capacity by 2032 and 244 GW by 2037.

The cost gap

• New coal projects selected by competitive bidding in 2025 came in at ₹5.38 to ₹6.30 per unit.
• Solar in 2026 costs roughly ₹2.10 to ₹3.50 per unit, often under ₹2.50.
• So new coal is often twice as costly as new solar.
• Why add coal anyway? Solar and wind cannot yet guarantee round-the-clock power. Coal can.

A water-hungry industry

• About 90% of India’s thermal generation depends on freshwater cooling.
• Roughly 40% of thermal plants sit in regions with high water stress.
• Between 2013 and 2016, 14 of the 20 largest thermal utilities had at least one water-shortage shutdown.
• Those shutdowns cost about $1.4 billion.

Generators waiting to be paid

• Discoms owed generators about ₹717.5 billion for the April 2025 billing cycle alone.
• Total discom debt was near ₹7.26 lakh crore as of March 2025.
• Legacy dues fell from about ₹1.39 lakh crore in 2022 to roughly ₹4,927 crore by January 2026.
• That is a different, smaller number from the total outstanding dues. Do not confuse the two.

CAPF (ACs) 2025: where is Ghatampur?

• The Ghatampur Thermal Power Project is in Kanpur district, Uttar Pradesh, run by NLC India.
• (Source: CAPF (ACs) 2025, Q8.)

CDS I 2023: how a thermal plant works

• The question said burning fuel to heat water into steam, which spins a turbine, explains how a thermal station makes electricity.
• Both parts are true, and the second explains the first.
• (Source: CDS I 2023, Q90.)

UPSC CSP 2020: coal ash and coal plants

• All three statements were correct: coal ash contains arsenic, lead and mercury.
• Coal plants release sulphur dioxide and oxides of nitrogen.
• Indian coal has high ash content.
• These facts are often split across distractors. Learn all three together.
• (Source: UPSC CSP 2020, Q79.)

UPSC CSP 2023: three “none of them” claims

• The claims were that no coal plant uses seawater, none sits in a water-stressed district, and none is privately owned.
• All three are false, because one genuine exception breaks a “none” claim.
• The seawater-cooled example is the Tata Mundra Ultra Mega Power Project in Gujarat.
• It is a different plant from Adani’s Mundra Thermal Power Station, though both are in the same port town.
• See Coal Thermal Power Plants: Three “None of Them” Claims, All False.
• (Source: UPSC CSP 2023, Q66.)

NDA & NA (II) 2025: who gets Vindhyachal’s power?

• The question asked which state is not a beneficiary.
• Gujarat, Goa and Maharashtra are. Uttar Pradesh is not.
• A companion question matched plants to states, and only two of four pairs were right.
• Panki is in Uttar Pradesh and Wanakbori is in Gujarat.
• Parli is in Maharashtra, not Karnataka. The Vijayawada plant is in Andhra Pradesh, not Telangana.
• Verify the real state before answering.
• (Source: NDA & NA (II) 2025, Q129.)

NDA-NA-2 2017: where is Koradi?

• Koradi Thermal Power Station is in Nagpur, Maharashtra.
• It has run since 1974 and is one of four major plants serving the power-surplus Vidarbha region.
• (Source: NDA-NA-2 2017 question.)

Renovating 223 ageing coal units

• On 6 August 2026, a Lok Sabha reply detailed the Renovation and Modernisation programme for ageing coal plants.
• Under 2023 guidelines, the CEA identified 223 units older than 20 years as R&M candidates.
• Together they represent 63,440 MW.
• The upgrades run in nine phases, from January 2024 to June 2046.
• The Centre does not fund this directly. Each generating company must finance its own R&M works.

Coal output and NTPC

• On 20 March 2025, India’s annual coal production crossed 1 billion tonnes for the first time, in FY 2024-25.
• The country produced about 1,047.52 million tonnes that year, with Coal India supplying the bulk.
• The government now targets 1.5 billion tonnes a year by 2030.

Discoms still owe generators

• As of the April 2025 billing cycle, discoms owed generators about ₹717.5 billion, per the PRAAPTI portal.
• Their average payment delay improved to 113 days in FY 2025, from a high of 176 days in FY 2021.
• The underlying debt burden remains large.