Non-Conventional Sources of Energy in India

1. Hydroelectricity

Significance

• Coal and petroleum are exhaustible; hydroelectricity is renewable, cheap, clean, and environmentally benign.
• River water, if not harnessed, drains wastefully into the sea.
• Hydropower currently makes up about 56.6 GW of India's installed capacity (51.4 GW large hydro + 5.2 GW small hydro), out of a total non-fossil capacity of 283.5 GW (as on 31 March 2026).

Potential

• India's economically exploitable large-hydro potential is estimated at 1,33,410 MW (CEA reassessment, 2017–2023).
• An additional 1,76,280 MW of pumped storage potential has been identified for grid balancing.
• Only around 27–28% of large-hydro potential has been developed so far.
• Reasons for slow development: erratic, monsoon-dependent river flow; lack of natural waterfalls on many rivers requiring costly dam construction; remote project locations; geological and environmental clearance challenges; inter-state disputes.

Transmission Losses

• About 8% loss of energy over 160 km of transmission, and 21% loss over 800 km.
• Example: Bhakhra Nangal to Delhi involves roughly 15% loss.

Historical Development

• NHPC has completed 8 hydel projects with a combined capacity of 2,193 MW.
• CEA has cleared 24 new hydro/pumped-storage schemes totalling 15,569 MW over the past decade.

Rivers and Suitability

Himalayan (Northern) Rivers

• Perennial — fed by both monsoon rain and glacial snowmelt, giving year-round flow.
• High water velocity due to steep gradients and dissected terrain.
• Low competition with other water uses; water can also serve irrigation.
• Hold roughly three-fourths of India's total hydel potential (Indus, Ganga, Brahmaputra basins).

Peninsular Rivers

• Entirely rain-fed, so flow is erratic — high in the monsoon, very low in the dry season.
• Not perennial; require storage dams to regulate flow.
• Potential concentrated mainly in hilly regions: Western Ghats, north-western Karnataka, Nilgiri and Anamalai Hills, upper Narmada basin.
• Upper reaches are often unsuited to irrigation, so hydel projects there don't compete with other water uses.
• The southern and western peninsula is far from coal deposits, increasing reliance on hydel power.

Generation Trend

• Hydropower generation is highly rainfall-dependent. In FY 2023-24, output fell by 16.3% — the sharpest decline in 38 years — due to poor monsoon, pushing hydro's share of total electricity generation to a historic low of 8.3%.
• The Koyna Hydroelectric Project (Maharashtra, on a tributary of the Krishna river) is India's largest completed hydro plant, at 1,960 MW.
• India ranks 5th globally in installed hydroelectric capacity.

States and Hydroelectricity

• Wholly dependent on hydroelectricity: Himachal Pradesh, Meghalaya, Nagaland, Sikkim, Uttarakhand — all hilly/mountainous states.
• Strongly dependent: Jammu & Kashmir, Kerala, Mizoram, Odisha.
• Leading states by installed capacity: Andhra Pradesh (with Telangana), Karnataka, Kerala, Maharashtra, Odisha, Punjab, Rajasthan, Tamil Nadu.

Major Projects by State

2. Solar Energy

Potential

• India receives about 3,000 hours of sunshine annually, equivalent to over 5,000 trillion kWh — far exceeding total national energy consumption.
• Daily average solar radiation ranges from 4 to 7 kWh/m², depending on location.
• The Thar Desert (Rajasthan) has the potential to become one of the world's largest solar hubs, with capacity estimated between 700 and 2,100 GW; part of it has been declared a Solar Energy Enterprise Zone.
• Other high-potential regions: Kathiawar Peninsula, Maharashtra, Karnataka, Andhra Pradesh, Telangana, Madhya Pradesh, West Bengal, Jharkhand, Bihar, Uttar Pradesh, Haryana, Punjab.

Applications

Cooking, water heating, drying farm produce, water pumping, home and street lighting, decentralised power for villages, schools, and hospitals.

Current Standing

• Solar is now India's largest renewable energy source, making up roughly 55–56% of total renewable capacity, with installed capacity around 150–162 GW.
• India added close to 29 GW of new solar and wind capacity in the first half of 2026, with utility-scale solar additions up 32% year-on-year.
• Rooftop solar is the fastest-growing segment, adding 6.4 GW in H1 2026 — a 104% increase over the previous year — driven mainly by the PM Surya Ghar: Muft Bijli Yojana, a scheme providing free electricity through household rooftop solar installations.
• PM-KUSUM supports solar adoption in agriculture through solar pumps and decentralised solar plants on farmland.
• Rajasthan is India's largest solar state (~41.7 GW cumulative); Gujarat leads in overall renewable capacity (~49 GW) and led fresh solar additions in H1 2026 (7.6 GW), followed by Rajasthan (6.6 GW) and Tamil Nadu (2.4 GW).

Major Solar Projects by State

Solar Thermal Applications

Solar Water Heaters

• Flat plate collectors heat water up to 80°C for use in homes, hotels, hospitals, and industries.
• Typical payback period: 3–6 years.
• Technical potential estimated at 140 million sq metres of collector area.
• 1,000 domestic units (100 litres each) can shave about 1 MW off peak electricity demand.

Solar Cookers

• Box cooker: serves a family of 4–5; saves 3–4 LPG cylinders per year.
• Dish (concentrating) cooker: serves 10–15 people; saves up to 10 LPG cylinders per year.
• Community cooker (Scheffler type): serves around 40 people; saves 35 LPG cylinders per year.
• Solar steam cooking systems serve thousands and are used at temples, ashrams, and gurudwaras — for instance, a system at Shirdi serves 3,000 devotees daily, and the Tirumala Tirupati Devasthanam operates the world's largest such system, with capacity for 15,000 pilgrims.

Solar Photovoltaic (SPV)

• Converts sunlight directly into electricity with no moving parts and no pollution.
• Used for lighting, water pumping, and telecommunications in remote, hilly, desert, and island regions.
• Solar greenhouses support off-season vegetable growing in Leh and Kargil; solarised huts help retain warmth in cold regions of Jammu & Kashmir and Himachal Pradesh.

3. Wind Energy

Advantages

• Costs are concentrated at the initial stage; generation begins immediately after commissioning.
• Roughly 20 years of near cost-free generation follow, since there is no recurring fuel cost.

Potential and Resource Mapping

• The Centre for Wind Energy Technology (C-WET) has assessed India's wind potential at 1,02,778 MW at 80 metres hub height, assuming 2% land availability.
• Gujarat has the highest wind potential, followed by Andhra Pradesh, Tamil Nadu, and Karnataka.
• Best wind resource zones: coastal Gujarat, Tamil Nadu, Andhra Pradesh, Odisha, West Bengal, and inland areas of Maharashtra, Madhya Pradesh, and Rajasthan.

Current Standing

• Installed wind capacity stands at roughly 56–57 GW.
• Growth has been uneven — wind additions dipped in early 2026 even as solar surged, before rebounding sharply mid-year.
• Gujarat and Tamil Nadu remain India's leading wind states; Gujarat led fresh wind additions in H1 2026 (1.2 GW), followed by Maharashtra and Karnataka.
• India is the world's 4th-largest wind energy market.

Major Wind Projects by State

Offshore wind (emerging): India's first offshore wind auction (1 GW) was launched in 2024, with identified zones at the Gulf of Khambhat (Gujarat) and the Thoothukudi–Kanyakumari coast (Tamil Nadu). A target of 37 GW of offshore wind by 2030 has been set, backed by a Viability Gap Funding scheme.

4. National Renewable Energy Targets and Schemes

• Target: 500 GW of non-fossil electricity capacity by 2030.
• The National Electricity Plan projects total installed capacity (all sources) of about 900 GW by 2031-32.
• India ranks 3rd globally in renewable energy installed capacity, having overtaken Brazil.
• Renewables met a record 51.5% of India's electricity demand on a peak day in July 2025.
• Non-fossil capacity addition in FY 2025-26 stood at 55.3 GW, the highest ever annual increase.
• Flagship schemes: PM Surya Ghar: Muft Bijli Yojana (rooftop solar), PM-KUSUM (solarising agriculture).

5. Other Renewable Sources

Biogas / Bioenergy

• Biogas is produced through anaerobic digestion of cattle dung, agricultural residue, and organic waste, yielding methane-rich gas usable for cooking, lighting, and power generation.
• India's biogas programme has evolved into the National Bioenergy Programme, run by MNRE, covering small household/community biogas plants as well as industrial-scale bio-methanation.
• Compressed Biogas (CBG): Biogas purified to ~98% methane content, compressed for use as a transport fuel or piped gas substitute.
  • The SATAT scheme originally targeted 5,000 CBG plants by 2023–25; only around 200–220 plants had been commissioned by mid-2026, well short of target.
  • GOBARdhan (Galvanising Organic Bio-Agro Resources Dhan), launched in 2018, supports conversion of cattle dung and organic waste into biogas and bio-slurry (organic manure) through Gram Panchayats and rural entrepreneurs.
  • In 2026, the Union Cabinet approved an upgraded GOBARdhan National Circular Bioenergy Scheme, with an outlay of ₹23,731 crore, to be implemented from FY 2026-27 to FY 2035-36 — aiming for roughly a ten-fold increase in domestic CBG production.
  • A Compressed Biogas Obligation now mandates blending of CBG into CNG/PNG networks, starting at 1% for FY 2025-26 and rising in subsequent years.
• India has an extensive network of several million small-scale household/community biogas plants, alongside a growing number of large CBG facilities.

Geothermal Energy

• Geothermal energy taps heat stored within the Earth's crust, brought to the surface via hot springs, geysers, or drilled wells.
• Key resource areas: Puga Valley and Chumathang (Ladakh, J&K), Manikaran (Himachal Pradesh), Tattapani (Chhattisgarh), Jalgaon (Maharashtra), Tapovan (Uttarakhand), and the Cambay Basin between the Narmada and Tapi rivers (Gujarat).
• Puga Valley hot springs range from 30°C to boiling point (~84°C), with total estimated geothermal potential across India of about 10,600 MW, Puga and Chumathang being the most promising sites.
• India's first demonstration-scale geothermal power project is under development at Puga, led by ONGC's Energy Centre — a 1 MW pilot (binary cycle) plant.
• A National Policy on Geothermal Energy (2025) aims to establish geothermal as a major pillar of the renewable mix, with a target of around 1 GW by 2030.
• Applications extend beyond electricity generation to direct-use heating — greenhouses, aquaculture, and space heating in cold regions like Ladakh.

Tidal Energy

• Tidal power harnesses the rise and fall of sea levels (and associated water flow) to generate electricity, typically using barrages or tidal-stream turbines.
• India's most promising tidal sites are the Gulf of Khambhat (Cambay) and the Gulf of Kutch in Gujarat, and the Sundarbans in West Bengal, owing to their large tidal ranges.
• India's first mini tidal power project (3.75 MW), approved in 2011, was planned for Durgaduani Creek in the Sundarbans, West Bengal.
• Tidal energy remains at a nascent/pilot stage in India, with a policy target of roughly 1 GW by 2030, constrained by high project costs (estimated ₹25–30 crore per MW) and environmental concerns around barrages affecting coastal ecosystems.

Wave Energy

• Wave energy captures power from surface ocean waves or sub-surface pressure fluctuations.
• India's National Institute of Ocean Technology (NIOT) leads research and pilot deployment, including small-scale wave energy pilots (e.g., in the Andaman & Nicobar Islands).
• Still at the research and pilot-project stage in India, with commercial deployment limited by technology costs and the need for coastal infrastructure.

Ocean Thermal Energy Conversion (OTEC)

• OTEC exploits the temperature difference between warm surface seawater and cold deep water to drive a modified Rankine-cycle engine and generate electricity.
• In 2003, NIOT attempted to build and deploy a 1 MW demonstration OTEC plant in collaboration with Saga University, Japan.
• India's long coastline and tropical waters offer a natural thermal gradient suited to OTEC, but the technology remains experimental and costly, with no significant commercial-scale project operational yet.

Common Challenges Across These Sources

• High per-MW capital costs compared to solar and wind (geothermal: ~₹15–20 crore/MW; tidal: ~₹25–30 crore/MW).
• Limited domestic technology base — reliance on imported/foreign technology, particularly for geothermal and tidal systems.
• Underdeveloped infrastructure: biomass supply chains, geothermal drilling capacity, and coastal grid connectivity all need expansion.
• Environmental concerns: land use for biomass cultivation, and ecological impact of tidal barrages on coastal habitats.
• Low public awareness and adoption, especially for household/community biogas in rural areas.