Non-conventional sources of energy

Also called: Renewable energy · Topic: Environment and Sustainable Development · NCERT: Class 11, Ch 7 "Environment and Sustainable Development"

Meaning

Non-conventional sources of energy are energy sources that renew themselves naturally, are spread out across many places, and cause very little pollution. Examples are wind, the sun, small mountain streams (mini-hydel) and biogas.

• Why it matters: India gets much of its power from thermal plants and large dams. Both harm the environment. Non-conventional sources cut these harms and can also bring power to remote villages that the grid does not reach.
• This makes the concept central to sustainable development. Sustainable development, in the Brundtland idea, means meeting today's needs without harming the ability of future generations to meet theirs.

Explanation

Why India needs them: the problem with conventional sources

Conventional sources are coal, oil, gas and large hydro. Two of them cause serious harm.

• Thermal power plants burn coal, which causes two problems:
• They release carbon dioxide (CO2), a greenhouse gas that warms the planet.

• They leave fly ash, the fine powder left after coal burns. When it is dumped near plants, it pollutes land and water.

• Large hydroelectric projects need big dams, which cause two problems:

• The reservoir floods forests and forces the people living there to move.

• The dam changes the natural flow of the river, which harms fish, the movement of silt and farmers downstream.

• Non-conventional sources avoid most of this harm. They are renewable, spread out and low-polluting.

• NCERT error: the Class 11 chapter calls wind and solar "conventional". In the exam, treat them as non-conventional.

The main types

1. Wind power

• Wind turbines, placed where the wind is strong and steady, turn the energy of moving air into electricity.
• Costs:
• The initial (capital) cost is high, because turbines, towers and grid links are expensive.
• Running costs are low, because wind is free and needs no fuel.

• NCERT says the long-run benefits recover ("absorb") the high starting cost.

• Drawbacks:

• Wind farms need large areas of land.
• The blades make noise, and birds and bats are killed when they hit them.
• Wind is intermittent (it does not blow all the time), so the grid needs back-up power or storage.

2. Solar photovoltaic (PV) power

• Photovoltaic cells (thin layers of a semiconductor, usually silicon) turn sunlight directly into electricity.
• Advantages:
• No pollution while running.
• No moving parts, so little maintenance.
• Ideal for remote areas such as hill villages, islands, deserts and border posts, where building grid lines is impossible or too costly.

• Panels can sit on rooftops, so no new land is needed.

• Limits:

• No power at night and less on cloudy days, so batteries or back-up are needed.
• Large solar parks need land.

3. Mini-hydel plants (small hydro)

• Small turbines are placed on perennial mountain streams (streams that flow all year). The falling water turns the turbines.
• Advantages:
• No change in land use, because no big dam or reservoir is needed.
• Forests and villages stay where they are.

• They meet local demand, for example in hill villages.

• Power is used close to where it is made, so:

• no large transmission lines are needed;
• there is no transmission loss (electricity lost as heat when power travels long distances through wires).

4. Biogas (gobar gas)

• Biogas is made by anaerobic digestion: cattle dung and other organic waste break down without air inside a closed tank.
• One input gives two outputs:
• a methane-rich gas (about 55-65% methane), used for cooking and lighting without smoke;

• leftover slurry, a very good organic fertiliser and soil conditioner (it improves soil structure).

• Burning dung cakes throws away this fertiliser value.

Worked example: why local generation saves energy

• A hill town needs 1,000 units of power.
• Distant plant: if 15% of the power is lost in the wires, the plant must produce 1,000 ÷ 0.85 ≈ 1,176 units.
• Mini-hydel plant next to the town: it needs to produce only about 1,000 units.
• Saving: about 176 units, which means less fuel and less money spent.

What limits their growth

• Intermittency: wind and solar are not always available, so storage and grid balancing are needed.
• Land need: wind farms and solar parks take up large areas.
• High upfront cost: this is why schemes give subsidies (for example, CFA for rooftop solar and solar pumps).

In India

• Ministry: MNRE (Ministry of New and Renewable Energy) manages the sector.
• MNRE counts hydro projects up to 25 MW as small hydro. Anything above 25 MW is large hydro.

• Since 2019, large hydro has also been counted as renewable energy in official figures.

• Milestone: India reached 50% of its installed electricity capacity from non-fossil sources in June 2025. This was five years ahead of its 2030 target, which is part of its NDC (Nationally Determined Contribution) pledge under the Paris Agreement [3].

• Target: 500 GW of non-fossil capacity by 2030 [3].
• Latest capacity (31 March 2026):
• Non-fossil capacity was 283.46 GW: 274.68 GW renewable energy (RE) plus 8.78 GW nuclear [2].
• Within RE: solar 150.26 GW, wind 56.09 GW, large hydro 51.41 GW, bio-energy 11.75 GW and small hydro 5.17 GW [2].

• India ranks third in the world in installed RE capacity (2026) [2].

• Solar growth: from 2.8 GW (2014) to 150.26 GW (31 March 2026) [2][3]. Solar makes up about 48% of India's RE capacity (2026) [3].

• Wind growth: India added 6.05 GW in FY 2025-26. This was the highest-ever yearly wind addition and 46% more than in FY 2024-25 [3].
• Small hydro: a later MNRE update puts it at 5.10 GW commissioned, with 0.44 GW more under implementation (2026) [3].
• International Solar Alliance (ISA):
• Launched by India and France at COP21, Paris, on 30 November 2015.
• Its Framework Agreement came into force in December 2017, which made it a treaty-based intergovernmental organisation.
• Headquarters: Gurugram (Haryana). It is the first international intergovernmental body with its headquarters in India.

• Vision: "One Sun One World One Grid" (OSOWOG), which means linking solar grids across countries so that solar power made in one time zone can be used in another.

• Key schemes:

• PM-KUSUM (2019): solar power for farmers. It aims to de-dieselise farming (replace diesel pumps with solar pumps) [8].
  • Component A: small solar plants up to 2 MW on farmers' land.
  • Component B: standalone solar pumps (not connected to the grid).
  • Component C: solarising existing grid-connected pumps. Farmers can sell extra power to the DISCOM (electricity distribution company) [8].
  • Target: 34.8 GW, with central support of ₹34,422 crore. The scheme was extended to 31 March 2026 [8].
  • More than 9 lakh standalone pumps were installed under Component B by October 2025 [8][9].
• PM Surya Ghar: Muft Bijli Yojana (February 2024): rooftop solar for 1 crore households, giving up to 300 free units a month. Outlay: ₹75,021 crore [5].
  • CFA (Central Financial Assistance, the Centre's share of the cost) is ₹30,000 per kW for the first 2 kW and ₹18,000 for the third kW. The maximum is ₹78,000 [5].
  • There were 26,19,879 rooftop systems by 19 March 2026, with ₹17,967.53 crore of CFA disbursed [4].
• GOBARdhan: in 2026, the Cabinet approved it as India's National Unified Scheme for Compressed Biogas, with an outlay of ₹23,731 crore. It aims to raise domestic CBG output nearly ten-fold [7].

Don't confuse with

• Conventional sources of energy: coal, oil, gas and large hydro. They are centralised and cause more harm (CO2, fly ash, displacement). Wind and solar are non-conventional, even though NCERT wrongly calls them "conventional".
• Non-fossil capacity: this is wider than renewable energy. It also includes nuclear. For example, 283.46 GW non-fossil = 274.68 GW RE + 8.78 GW nuclear (31 March 2026) [2].
• Small hydro vs large hydro: small hydro (up to 25 MW, MNRE) needs no big dam and no change in land use. Large hydro needs dams that displace people, even though it has been counted as RE since 2019.
• Compressed Biogas (CBG) vs CNG: CBG is renewable, made from purified biogas taken from dung or organic waste. CNG is fossil natural gas. Both can run vehicles.

Prelims Hooks

• Trap: NCERT Class 11 calls wind and solar "conventional". The correct answer is non-conventional.
• Small hydro under MNRE = projects up to 25 MW. Mini-hydel plants need no change in land use and have no transmission loss.
• ISA: launched by India and France at COP21, Paris (30 November 2015). Framework Agreement in force in December 2017. HQ in Gurugram. Vision: One Sun One World One Grid.
• 50% non-fossil installed capacity was reached in June 2025, five years ahead of the 2030 NDC goal. The 2030 target is 500 GW non-fossil [3].
• PM-KUSUM components: A = small solar plants up to 2 MW; B = standalone solar pumps; C = solarising grid-connected pumps [8].
• Biogas is made by anaerobic digestion (without air). It gives methane-rich gas plus slurry that is used as organic manure.

Mains Points

• Decentralised energy for inclusive growth:
• Rooftop solar, mini-hydel, solar pumps and biogas produce power where it is used. This cuts transmission losses and reaches villages the grid cannot.
• Farmers and households become "prosumers" (people who both produce and use power), which raises rural incomes.

• Links: PM-KUSUM [8], PM Surya Ghar [5], and SDG 7 (affordable, reliable, sustainable and modern energy for all).

• Clean energy has trade-offs:

• Wind and solar are intermittent, so India needs storage and grid balancing.
• Solar parks and wind farms need land.
• Wind has a high capital cost, although running costs are low.

• A balanced mix (RE plus storage plus small hydro plus gas as a bridge fuel [10]) supports the 500 GW by 2030 target [3] and intergenerational equity.

• Waste to wealth:

• Biogas and CBG (GOBARdhan [7], SATAT [6]) turn cattle dung and farm waste into fuel and manure. This cuts smoke from dung cakes, methane from dumped waste and the need for chemical fertiliser.
• Plants stay viable only with:
  • assured purchase prices;
  • steady supply chains for raw material.

Related concepts

• Wind power
• Solar photovoltaic power
• Mini-hydel plants
• LPG as clean fuel
• Biogas
• Compressed Natural Gas
• Road space rationing
• Energy poverty

Read more

• Strategies I: clean energy for villages, cities and remote areas