Biomass energy is energy obtained from organic matter of recent plant or animal origin, such as wood, crop residues, bagasse, animal dung and the organic part of municipal waste. It is stored solar energy: plants capture sunlight by photosynthesis, and that chemical energy is released as heat, electricity or fuel when the biomass is burned, gasified, digested or fermented. In India, bagasse and biomass cogeneration plants had a combined installed capacity of about 10,870 MW as of 31 August 2026, according to the Ministry of New and Renewable Energy (MNRE).
What is biomass energy?
Biomass is any organic material that was alive recently, as opposed to coal and oil, which are fossilised organic matter millions of years old. Biomass energy is the useful energy we get from it. The chain is simple:
- A plant uses sunlight to combine CO2 from the air with water, storing energy in carbohydrates such as cellulose, starch and sugar.
- The plant, or an animal that ate it, leaves residues: straw, husk, stalks, bagasse, dung.
- Conversion releases the stored energy, returning the carbon to the air as CO2.
Is biomass renewable and carbon-neutral?
Biomass is renewable because a new crop or forest can be grown to replace what was used, within months for crops and within years to decades for trees. It is often called carbon-neutral because the CO2 released on burning was absorbed from the air during growth, and would be released anyway if the residue rotted or was burned in the field.
That claim needs care. Biomass is only close to carbon-neutral when it is a genuine residue or is regrown at the rate it is used. Cutting forests faster than they regrow, clearing land for energy crops, and the diesel and fertiliser used in harvesting, transport and processing all add emissions. So it is more accurate to call well-managed biomass low-carbon rather than zero-carbon. For the broader distinction, see renewable vs non-renewable resources.
Sources of biomass
| Source | Examples | Typical use |
|---|---|---|
| Agricultural residues | Rice straw, wheat straw, rice husk, cotton stalks, maize cobs, coconut shells | Boiler fuel, briquettes and pellets, gasifiers |
| Agro-industrial residues | Bagasse from sugar mills, press mud, distillery waste | Cogeneration in sugar mills, biogas, compressed biogas (CBG) |
| Forestry and wood waste | Firewood, sawdust, wood chips, bark | Cooking, industrial heat, pellets |
| Animal waste | Cattle dung, poultry litter | Biogas for cooking, CBG |
| Municipal solid waste and sewage | Food and garden waste, sewage sludge | Waste-to-energy plants, biogas |
| Energy crops | Sugarcane and grains for ethanol, oilseeds such as jatropha for biodiesel, fast-growing grasses | Liquid biofuels |
How biomass energy works: from biomass to electricity, heat and fuel
There are three families of conversion route: thermochemical (heat), biochemical (microbes and enzymes) and chemical.
| Route | What happens | Main product |
|---|---|---|
| Direct combustion | Biomass is burned in a furnace or boiler | Heat and steam, then electricity via a steam turbine |
| Gasification | Partial burning with limited air at high temperature | Producer gas (CO, H2, CH4) for engines or heat |
| Pyrolysis | Heating without oxygen | Bio-oil, charcoal (biochar) and gas |
| Anaerobic digestion | Bacteria break down wet waste without air | Biogas (mainly methane and CO2); upgraded to CBG |
| Fermentation | Yeast converts sugars and starch | Ethanol, blended into petrol |
| Transesterification | Vegetable oils or fats react with methanol and a catalyst | Biodiesel |
Each route is covered in detail on our page on biomass conversion technologies, and small-scale digesters on biogas generation plants.
A typical biomass power plant works like a small coal plant. Fuel such as rice husk or straw is fed to a boiler, the steam drives a turbine and generator, and the exhaust steam is condensed and pumped back. In a cogeneration plant, such as a sugar mill, the same steam also supplies process heat, so the overall use of the fuel’s energy is much higher than for electricity alone.
Worked example: electricity from rice straw
Rice straw has a higher heating value of about 14 to 15 MJ/kg on a dry basis in published analyses. Take 14 MJ/kg to allow for some moisture, and a small steam power plant with an overall efficiency of 25% (fuel energy to electricity).
- Energy in 1 tonne of straw = 1,000 kg × 14 MJ/kg = 14,000 MJ.
- Convert to kWh: 14,000 MJ ÷ 3.6 MJ/kWh = 3,889 kWh of heat.
- Electricity = 3,889 × 0.25 = about 972 kWh, just under 1 MWh per tonne.
How much straw does a 10 MW plant need? Running at full load for 24 hours it produces 10 × 24 = 240 MWh, so it needs 240 ÷ 0.972 = about 247 tonnes of straw a day. Over a year at an 80% capacity factor it generates 10 × 8,760 × 0.8 = 70,080 MWh and burns about 72,100 tonnes. Collecting, baling and storing that much straw in the few weeks after harvest is the real engineering challenge, which is why fuel supply decides whether straw power plants succeed.
Biomass energy in India
- Power capacity: MNRE’s physical progress figures as on 31 August 2026 list 9,821 MW of bagasse cogeneration and 1,048 MW of non-bagasse biomass cogeneration, a total of about 10,870 MW. Grid-connected waste-to-energy adds another 324 MW. Bagasse cogeneration in sugar mills is by far the largest share.
- Ethanol blending: under the Ethanol Blended Petrol Programme, blending rose from about 1.5% in 2014 to 19.2% in ethanol supply year 2024-25, and to 20% (E20) in ESY 2025-26 (November 2025 to June 2026), according to the Ministry of Petroleum and Natural Gas. The original E20 target of 2030 was brought forward to 2025. Ethanol comes from sugarcane molasses and juice, and from grains.
- SATAT: the Sustainable Alternative Towards Affordable Transportation scheme, launched in October 2018, promotes compressed biogas (CBG) plants that turn agricultural residue, cattle dung, press mud and municipal waste into a methane-rich fuel sold through oil marketing companies.
- Co-firing in coal plants: the Ministry of Power’s biomass policy requires coal-based thermal power plants to co-fire 5% biomass pellets from FY 2024-25, rising to 7% from FY 2025-26. Pellets are largely made from agro-residues such as paddy straw.
Stubble burning: a fuel problem in disguise
Every October and November, farmers in Punjab and Haryana burn paddy straw in the fields to clear them quickly for the wheat crop, and the smoke adds to the winter air pollution in Delhi-NCR. The same straw is a biomass fuel. Turning it into pellets for co-firing, CBG, or fuel for straw-fired boilers gives it a value and removes the reason to burn it, provided collection is quick and cheap enough to fit the short gap between harvest and sowing.
Advantages of biomass energy
- Renewable and, when managed well, low-carbon.
- Uses waste that would otherwise rot, pollute or be burned in the open.
- Available on demand: unlike solar and wind, a biomass plant can run day and night and follow load.
- Creates rural income for farmers and jobs in collection and processing.
- Reduces imports of crude oil and gas through ethanol and CBG.
- Uses familiar technology: boilers, steam turbines and engines.
Disadvantages of biomass energy
- Low energy density: loose straw and husk are bulky and hold much less energy per cubic metre than coal, so collection, transport and storage are costly.
- Seasonal, scattered supply that must be collected and stored for the whole year.
- High ash and silica in rice straw and husk cause slagging and fouling in boilers.
- Burning biomass in open fires or poor stoves causes smoke and indoor air pollution.
- Energy crops compete with food crops for land and water.
- Not carbon-neutral if forests are cleared or regrowth does not keep pace.
Uses of biomass energy
- Electricity: biomass and bagasse power plants, and co-firing in coal plants.
- Industrial heat and steam: sugar mills, rice mills, paper mills, textile and food processing.
- Cooking and heating: firewood, dung cakes and household biogas, still common in rural India.
- Transport fuel: ethanol blended into petrol, biodiesel, and CBG for vehicles.
- Organic fertiliser: digestate from biogas plants is returned to fields.
References
- Ministry of New & Renewable Energy (MNRE), Government of India, physical progress of renewable energy programmes.
- IRENA – Bioenergy
- IEA – Bioenergy
FAQs
What is the definition of biomass energy?
Biomass energy is renewable energy obtained from organic material of recent plant or animal origin, such as wood, crop residues, animal dung and organic waste, by burning it or converting it into gas or liquid fuels.
How is biomass converted into electricity?
Most often by burning it in a boiler to raise steam that drives a turbine and generator. It can also be gasified to run a gas engine, or digested to make biogas for an engine generator.
Is biomass energy renewable?
Yes. Plants can be regrown and residues are produced every season. It is close to carbon-neutral only when the biomass is a true residue or is regrown as fast as it is used, and emissions from harvesting and transport are small.
What are the main uses of biomass energy?
Electricity generation, industrial heat and steam, household cooking and heating, and transport fuels such as ethanol, biodiesel and compressed biogas.
What are the disadvantages of biomass energy?
Low energy density, seasonal and scattered supply, high collection and transport costs, ash problems in boilers, smoke from poor combustion, and competition with food crops for land.
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