Bio-energy, biogas and biofuels

Detail

Where bio-energy sits in India's power mix

• Non-fossil capacity is electricity capacity that does not burn coal, oil or gas. It covers renewable energy plus nuclear power.
• India's target is 500 GW of non-fossil capacity by 2030. This was announced at COP26 (Glasgow, 2021) [7].
• On 31 October 2025, India's total installed capacity was 5,05,023 MW [7].
• Non-fossil sources made up 2,59,423 MW (51.37%) of this [7].

• Fossil sources made up 2,45,600 MW (48.6%) [7].

• India passed 50% non-fossil capacity in June 2025. This was more than five years ahead of its NDC target under the Paris Agreement (NDC, Nationally Determined Contribution: the climate pledge each country makes) [7].

• Bio-power is small inside this total (31 October 2025):
• Biomass power and cogeneration: 10,757 MW [7]. Cogeneration means one plant makes both heat and electricity. In sugar mills it burns bagasse, the crushed cane fibre left after the juice is taken out.
• Waste-to-energy: 856 MW [7].
• Solar was 1,29,924 MW and wind was 53,600 MW in the same table [7].

Bio-energy

• Bio-energy is energy taken from biological matter. This includes crop residue (stalks, straw and husk left after harvest) and municipal, industrial and other wastes.
• It can be turned into three forms:
• Electricity, by burning the material or burning gas made from it.
• Heat, for industry and homes.

• Cooking gas, made by letting waste rot.

• Benefits:

• It disposes of waste that would otherwise pile up in landfills.
• It raises rural incomes, because crop residue becomes something farmers can sell.
• It cuts pollution, for example by replacing open burning of stubble.

• It reduces pressure on fuelwood, so fewer trees are cut for cooking.

• Example: the Okhla waste-to-energy plant, Delhi.

• It burns city garbage to make electricity.
• Nearby residents have complained about smoke and emissions.

• Lesson: bio-energy is renewable, but burning mixed city waste can still pollute the air. Where the plant is sited matters.

• The policy umbrella is the National Bioenergy Programme (NBP). It supports bioenergy and waste-to-energy technology for clean energy and energy security [6]. Its Waste to Energy programme funds CBG/Bio-CNG projects that use urban, industrial and farm waste [4].

Biogas: how it forms

• Biogas is a fuel gas made when organic matter rots without air. Its main component is methane.
• Process, step by step:
• Inputs: shrubs, farm waste, and animal and human waste go into a closed tank called a digester.
• Process: with no oxygen inside, bacteria break the matter down. This is called anaerobic decomposition, meaning rotting without air.
• Result 1: a methane-rich gas collects at the top of the tank.

• Result 2: the leftover wet sludge, called slurry, is a rich manure.

• Thermal efficiency means how much useful heat a fuel gives. Biogas has higher thermal efficiency than kerosene, dung cake and charcoal.

• Scale: plants work at municipal, cooperative and individual (household) levels.

Gobar gas plants

• A gobar gas plant is a biogas plant that runs on cattle dung ("gobar").
• Why it is the most efficient use of cattle dung:
• Burnt as dung cake, dung gives only heat and smoke, and its nutrients are lost.

• Put through a gobar gas plant, the same dung gives fuel (gas) plus better manure (slurry).

• The table below compares the two uses.

Use of cattle dung	Fuel	Manure	Indoor smoke
Dung cake (burnt)	Low heat	None (nutrients burnt off)	High
Gobar gas plant	Methane-rich gas, higher heat	Nutrient-rich slurry	Very low

• These plants suit India because India has a very large cattle population and many rural homes still depend on biomass for cooking.

Compressed biogas (CBG), SATAT and GOBARdhan

• Compressed biogas (CBG) is biogas that has been cleaned and then packed under pressure.
• Cleaning removes carbon dioxide, hydrogen sulphide and moisture, which leaves mostly methane.
• CBG is chemically equivalent to natural gas, so it can go straight into existing gas pipelines and CNG networks [3].

• It is sold as vehicle fuel and industrial fuel.

• SATAT stands for Sustainable Alternative Towards Affordable Transportation.

• It was launched on 1 October 2018 [8].
• Under it, oil and gas marketing companies invite entrepreneurs to set up CBG plants and promise to buy their gas [8].

• The target is 5,000 CBG plants, with an investment of about ₹2 lakh crore [9].

• GOBARdhan stands for Galvanizing Organic Bio-Agro Resources Dhan.

• It was launched in 2018 under Swachh Bharat Mission (Grameen) as part of village solid and liquid waste management [3].

• It turns animal waste, kitchen leftovers, crop residue and market waste into biogas and bio-slurry [3].

• 2026 upgrade. On 6 August 2026, the Union Cabinet approved GOBARdhan as the National Circular Bioenergy Scheme, India's single national scheme for CBG [3].

• Outlay: ₹23,731 crore [3].
• Nodal ministry: MoPNG (Ministry of Petroleum and Natural Gas). The CBG work was earlier split across four ministries [3].
• Period: FY 2026-27 to FY 2035-36 [3].
• Aim: about ten-fold growth in domestic CBG production [3].
• CBG Obligation (CBO): city gas companies must mix CBG into their CNG (transport) and PNG (piped household gas) [3]:
  • 3% in FY 2026-27
  • 4% in FY 2027-28
  • 5% from FY 2028-29 onwards
• Fixed price: ₹2,110 per MMBTU (million British thermal units, a unit of heat energy), which equals ₹105 per kg of CBG [3].
• Capital help: up to ₹2 crore per tonne per day of plant capacity, plus credit guarantees covering up to 85% of loans to MSME projects [3].

• Expected gains over ten years: over ₹40,000 crore saved in foreign exchange, 10 MMT (million metric tonnes) of fossil fuel replaced, more than 40 MT of CO₂ cut, 250 MMT of organic fertiliser and over 1.5 lakh jobs [3].

• Progress on 6 August 2026 [3]:

• 1,908 CBG/Bio-CNG plants registered.
• 217 plants commissioned, producing 0.4 MMSCMD (million standard cubic metres per day).
• 339 plants under construction.

• (Target under SATAT: 5,000 plants.)

• Why it matters: India imports nearly 50% of its natural gas. About 55–60% of its LNG imports pass through the Strait of Hormuz (between Iran and Oman, linking the Persian Gulf to the Gulf of Oman and the Arabian Sea), so gas made at home adds security [3].

• Manure support: under the Market Development Assistance scheme, the Department of Fertilizers paid ₹1,500 per tonne for Fermented Organic Manure (FOM) made from CBG and GOBARdhan plants [3].

Ethanol blending

• Ethanol is an alcohol fuel made by fermenting sugar or starch with yeast.
• Ethanol blending means mixing ethanol into petrol. E20 means petrol with 20% ethanol.
• Policy base: the National Policy on Biofuels, 2018, amended in 2022.
• The 2018 policy allowed raw materials beyond sugarcane, such as maize and surplus grain [2].
• The 2022 amendment also allows [4]:
  • damaged food grains (broken rice, grain unfit for people to eat)
  • surplus grain, when the National Biofuel Coordination Committee declares a surplus
  • crop residue (rice straw, cotton stalk, corn cobs, sawdust, bagasse)
  • corn, cassava, rotten potatoes, maize, cane juice and molasses
• Molasses is the thick syrup left after sugar is taken out of cane juice.

Timeline

• 2001: pilot programme started [2].
• 2006: E5 (5% blending) introduced in several states [2].
• Up to 2014: blending stayed near 1.5%, because sugarcane alone could not supply enough ethanol [2].
• June 2022: E10 reached, five months early [2].
• 2025: E20 reached, five years before the original 2030 target. Year-wise blending by ethanol supply year [2]:

Ethanol supply year	Blending
2020-21	~8.1%
2021-22	10.0%
2022-23	12.1%
2023-24	14.6%
2024-25	19.2%
2025-26 (Nov–June)	20%

Scale and gains

• Ethanol production grew from about 40 crore litres around 2014 to about 400 crore litres by 2022 [5].
• Yearly ethanol availability later neared 1,200 crore litres [2].
• Results since ethanol supply year 2014-15, as reported in July 2026 [2]:
• over ₹1.97 lakh crore saved in foreign exchange
• about 316 lakh tonnes of crude oil replaced
• about 952 lakh tonnes of CO₂ cut

• over ₹1.66 lakh crore paid to farmers

• Octane: the Research Octane Number (RON) of ethanol is about 108.5, against 84.4 for petrol. E20 lifts the effective octane of Indian petrol to about 95 [2]. Octane measures how well a fuel resists "knocking" (burning too early inside the engine).

• E20 can cut lifecycle carbon emissions by nearly 40% [2].

Second- and third-generation ethanol

• First-generation (1G) ethanol is made from food crops such as cane, grain and maize.
• Second-generation (2G) ethanol is made from non-food lignocellulosic biomass: the tough, woody plant material in straw, stalks and bamboo.
• IOCL Panipat (Haryana): India's first commercial 2G ethanol plant. It runs on paddy straw and was dedicated to the nation on 10 August 2022 (World Biofuel Day) [4][5].
• Haryana and Punjab grow a lot of rice. Farmers burn the leftover stubble (parali), which adds to winter smog in Delhi-NCR.

• The plant gives that straw a buyer, which cuts stubble burning [5].

• Numaligarh (Assam): a bamboo-based 2G biorefinery, built by Numaligarh Refinery Ltd. through Assam Bio-Ethanol Pvt. Ltd. [4].

• Third-generation (3G) ethanol, IOCL Panipat: a plant that makes ethanol from refinery off-gas, the waste gas from oil refining [4].
• PM JI-VAN Yojana (2019, amended 2024) gives money for 2G projects [4][6].
• JI-VAN stands for Jaiv Indhan–Vatavaran Anukool fasal awashesh Nivaran.
• Over ₹908 crore was approved for six commercial and four demonstration 2G projects (as of December 2024) [6].

Trade-offs

• Water stress from sugarcane:
• Sugarcane needs a lot of water.
• It is grown mostly in Uttar Pradesh, Maharashtra and Karnataka. Parts of Maharashtra and Karnataka are drought-prone.

• The government is pushing farmers to move from rice and sugarcane to maize. It also promotes drip irrigation under "Per Drop More Crop" [4].

• Sugar diverted to ethanol: in sugar season 2024-25, 34 LMT (lakh metric tonnes) of sugar went to ethanol. Even so, sugar availability of 340 LMT was above domestic demand of 281 LMT [4].

• Maize diverted from animal feed:
• Maize output rose from 337.30 LMT (2021-22) to 443 LMT (2024-25) [4].

• More maize going into ethanol can raise the cost of poultry and cattle feed.

• Food versus fuel debate: grain and cane used for fuel could have fed people or animals. 2G ethanol from crop waste avoids this conflict.

• Older vehicles:
• Some vehicles may lose 3–5% of mileage on E20 [2].
• Owners have worried about rubber parts and fuel lines.

• The government reports no E20-related damage in 1.5 crore older vehicles serviced by Maruti Suzuki in FY 2025-26 [2].

• Cost: maize-based ethanol is bought at about ₹71.86 per litre. At crude prices near USD 70 a barrel, E20 can cost as much as plain petrol or more [2].

Prelims Hooks

• Biogas is mainly methane. It forms by anaerobic decomposition, meaning rotting without oxygen.
• Biogas has higher thermal efficiency than kerosene, dung cake and charcoal.
• A gobar gas plant gives two products: fuel gas and manure (slurry). That is why it is called the most efficient use of cattle dung.
• SATAT was launched on 1 October 2018 by MoPNG to promote CBG. Its target is 5,000 plants.
• GOBARdhan (2018) began under Swachh Bharat Mission (Grameen). In August 2026 it became the National Circular Bioenergy Scheme (₹23,731 crore, FY 2026-27 to 2035-36) under MoPNG.
• CBG Obligation in CNG and PNG: 3% (2026-27) → 4% (2027-28) → 5% (from 2028-29).
• Plant–place–feedstock pairs:
• Panipat (Haryana): 2G ethanol from paddy straw
• Numaligarh (Assam): 2G ethanol from bamboo

• Panipat: 3G ethanol from refinery off-gas

• Blending milestones: E5 (2006) → E10 (June 2022) → E20 (2025).

• Okhla waste-to-energy plant is in Delhi. It is an example of bio-energy that has faced local complaints about emissions.
• Trap: in installed capacity (October 2025), bagasse cogeneration (10,757 MW) is far larger than waste-to-energy (856 MW). Both are tiny next to solar.

Mains Points

• Bio-energy as circular economy (GS-III): CBG and 2G ethanol turn three problems into three gains.
• Stubble burning (Punjab, Haryana), dung and city waste become fuel and organic manure.
• Gas and crude imports fall, which matters given India's dependence on the Strait of Hormuz route.

• Farmers move from "Annadata" (food giver) to "Urjadata" (energy giver).

• Regional trade-offs:

• Water-hungry sugarcane in drought-prone Maharashtra and Karnataka.
• Maize diverted from poultry feed.
• The food-versus-fuel debate.

• Responses: shift to maize and 2G feedstock, drip irrigation, and zero liquid discharge (ZLD) distilleries.

• Implementation gap: only 217 of the 5,000 targeted CBG plants were commissioned by August 2026. Weak links were feedstock collection, prices, pipeline connections and loans. The 2026 GOBARdhan scheme answers these with assured purchase, a fixed price, capital help and credit guarantees.

• Decentralised energy for rural India: household and cooperative gobar gas plants cut indoor smoke, save women's time spent collecting fuelwood, protect forests and improve soil.
• Limit: city waste-to-energy plants such as Okhla show that location and emission control decide whether people accept them.