Compressed Biogas — Balancing Energy Security, Food Security, and Waste Management

India is the world's third-largest oil consumer but produces barely 15% of what it needs. Nearly 85% of crude oil is imported. About 90% of India's LPG imports transit through the Strait of Hormuz — a single narrow waterway between Iran and Oman. Any instability in West Asia doesn't just raise prices; it threatens physical supply. This is not a theoretical risk. The Israel-U.S.-Iran war disrupted supplies through this very route.

Energy security, at its core, means three things: availability (can you get the fuel?), affordability (can you pay for it?), and sustainability (can you keep using it without destroying the environment?). India's biofuel push addresses all three — at least in theory.

India's first ethanol blending mandate came in 2003. For over a decade, progress was negligible. By 2014, only 1.5% of petrol was blended with ethanol. Then came aggressive policy intervention: better pricing for sugar mills and grain-based ethanol producers, infrastructure investment, and clear targets. By December 2025, India hit 20% blending — five full years ahead of the original 2030 deadline. This is a genuine, globally recognised success story.

The government now wants to replicate this success with Compressed Biogas (CBG). The logic is compelling. Unlike ethanol (which needs sugarcane, maize, or grain), biogas can be made from materials that are currently waste — cattle dung (India has over 300 million cattle), crop residue (which farmers burn every winter, choking northern India's air), food waste from cities, and sewage. You don't need new farmland. You don't need new water. You just need to collect and process what already exists.

Think of it as nature's own recycling, done in a sealed tank. Organic waste — dung, crop stalks, food scraps — goes into an airtight chamber. Bacteria that thrive without oxygen begin breaking it down. First, one set of bacteria converts complex organic molecules into simpler acids. Then another set — called methanogens — converts those acids into methane and carbon dioxide. The gas rises to the top. The leftover slurry at the bottom is a nutrient-rich organic fertiliser called digestate. Purify the gas (remove the CO₂ and trace hydrogen sulphide), compress it, and you have CBG — chemically identical to the CNG that runs auto-rickshaws and city buses. It can go straight into the existing gas pipeline network. No new engines, no new burners, no new infrastructure at the consumer end.

And because the carbon in this methane came from plants that absorbed CO₂ while growing, burning CBG releases that same carbon back — no net addition to the atmosphere. This is what "carbon-neutral" means. It is not zero-emission (combustion still produces CO₂), but the carbon cycle is closed, unlike fossil CNG which brings ancient underground carbon into the atmosphere for the first time.

There is a second climate benefit most people miss. If cattle dung and crop residue decompose in the open — which is what happens now — they release methane directly into the air. Methane is roughly 80 times more potent than CO₂ as a greenhouse gas over a 20-year period. Capturing that methane in a biogas plant and burning it as fuel converts it to CO₂, which is far less harmful. So biogas doesn't just avoid fossil fuel emissions — it actively prevents worse emissions from open waste.

SATAT (Sustainable Alternative Towards Affordable Transportation): Launched in October 2018 by the Ministry of Petroleum and Natural Gas. The design is a market mechanism: entrepreneurs set up CBG plants, and oil marketing companies (IOC, BPCL, HPCL) guarantee to buy the CBG at an assured price. Target: 5,000 plants by 2023. Reality: 132 completed by June 2026. The gap is staggering.

GOBARdhan (Galvanising Organic Bio-Agro Resources Dhan): Launched in 2018 under the Swachh Bharat Mission (Grameen), this provides the financial support that SATAT doesn't. Grants of up to ₹50 lakh per district for community biogas plants. ₹564 crore earmarked for biomass collection machinery. ₹994 crore for pipelines connecting biogas plants to the gas grid.

Mandatory blending obligation: In 2023, the National Biofuels Coordination Committee approved mandatory CBG blending into city gas supply — starting at 1% in FY26, rising to 5% by FY29. The Finance Minister confirmed this mandate in the 2024 Budget speech.

National Bioenergy Programme: Under MNRE (Ministry of New and Renewable Energy), this supports biogas, biomass power, and biomass cogeneration projects.

Why have these programmes fallen short? The challenges are structural, not just financial.

• High upfront capital costs. A commercial CBG plant costs ₹15–25 crore. Rural entrepreneurs and farmer producer organisations don't have that kind of money.
• Credit access. Banks treat biogas as high-risk. Most rural operators cannot access formal project finance. The government's credit guarantee schemes exist on paper but haven't percolated.
• Feedstock supply chain. Dung and crop residue are dispersed across millions of small farms. Collecting, transporting, and storing them year-round is logistically hard. Crop residue is seasonal — paddy straw is available only in October-November. A plant that runs only part of the year cannot recover its costs.
• Technology gaps. India's biogas sector is still largely based on small-scale traditional gobar gas plants. Scaling up to compressed, pipeline-quality CBG requires purification technology, compression equipment, and quality testing infrastructure that India doesn't yet manufacture at scale.
• Water consumption — the hidden cost. Anaerobic digestion requires significant amounts of water to maintain the slurry. A commercial CBG plant processing 100 tonnes of feedstock per day may need 200–300 kilolitres of water daily. In water-stressed regions — which is where much of India's cattle population lives — this is a real constraint. Denmark manages this because its plants use manure, which already has high moisture content. If India's plants use dry crop residue, the water requirement goes up.
• Fragmented institutional ownership. SATAT sits with MoPNG. GOBARdhan sits with the Department of Drinking Water and Sanitation. The National Bioenergy Programme sits with MNRE. Agricultural waste policy sits with MoA. Stubble burning control sits with MoEFCC and CAQM. No single ministry owns the end-to-end biogas value chain.

It is important not to lose these in the discussion of challenges. The benefits are genuinely transformative if the programme scales.

• Energy security. Every tonne of CBG produced replaces imported CNG. At scale (the 5,000-plant target), this could replace ~15 million tonnes of CNG imports annually.
• Waste management. India generates over 62 million tonnes of municipal solid waste annually (CPCB data). Only 28% is processed. Biogas can absorb the organic fraction — roughly 50% of urban waste. For rural India, it processes cattle dung (which currently lies in open pits) and crop residue (which is currently burned).
• Stubble burning reduction. Punjab and Haryana alone generate about 35 million tonnes of paddy straw annually. Farmers burn most of it because they have only 15–20 days between the rice harvest and wheat sowing. If biogas plants offer a price for this straw, burning becomes economically irrational. This directly addresses northern India's annual air pollution emergency.
• Rural employment and income. Each CBG plant employs 30–50 people directly — in collection, transport, plant operation, and digestate marketing. For rural India, this is non-farm employment generated from existing agricultural waste.
• Organic fertiliser byproduct. The digestate left after biogas extraction is rich in nitrogen, phosphorus, and potassium. It can substitute chemical fertilisers, reducing India's fertiliser import bill (India imports almost all its potash and a significant share of phosphatic fertilisers). The Paramparagat Krishi Vikas Yojana and the biogas push could be natural complements — but this linkage is barely operationalised.
• Women's drudgery reduction. In rural India, women spend hours collecting firewood and dung cakes for cooking fuel. Household-level biogas plants — simpler and cheaper than commercial CBG plants — can eliminate this entirely. The National Biogas and Manure Management Programme (NBMMP) has been promoting these since the 1980s, but coverage remains limited.

This is where the development-conservation tension — the frame through which UPSC will test this topic — becomes sharpest.

When a government badly wants a biofuel programme to succeed, it starts offering better prices for the feedstock that produces that fuel most efficiently. For ethanol, that feedstock turned out to be maize. The government fixes per-litre ethanol prices by feedstock type. Between FY22 and FY25, the administered price of maize-based ethanol grew at a compound annual growth rate (CAGR) of 11.7% — making maize significantly more profitable than pulses, oilseeds, or millets.

The result is visible in the data. National maize yield rose from roughly 2.56 tonnes per hectare in FY16 to 3.78 tonnes per hectare in FY25. Meanwhile, yields for soybeans, sunflower, rapeseed, peanuts, and millets either stagnated or declined. Pulse production fell. The Economic Survey 2026 flagged this explicitly: maize cultivation has increased sharply, potentially affecting crop diversity and food security.

India already imports large quantities of pulses and edible oils to meet domestic demand. A policy designed to reduce import dependence on crude oil may be quietly deepening import dependence on food. And food import dependence carries its own vulnerability to global price shocks, supply disruptions, and currency fluctuations.

Germany's cautionary tale. After introducing its Renewable Energy Sources Act in 2000, Germany incentivised biogas production with guaranteed incomes, bonuses for operators, and encouragement for small-scale plants. The result was "corn mania" — maize cultivation surged because it was the most efficient and profitable feedstock. Food crop diversity collapsed. Over a decade later, the government was forced to introduce a cap on maize use in biogas plants.

Denmark's smarter path. Denmark is targeting 100% biomethane in its gas system by 2030. But it deliberately prohibited the use of food crops as feedstock. The primary inputs are livestock manure and agricultural waste — materials that would otherwise be pollutants, not food. This design achieves both energy transition and food security simultaneously.

India's challenge is to pursue energy security through biogas without repeating Germany's mistake. The trade-off is real but manageable — IF feedstock policy is designed with discipline.

The government's reasoning is sound on the demand side: mandatory blending creates a guaranteed market, which attracts investment. The ethanol success proves this model works.

The critics' worry is equally valid: if crop-based feedstock gets preferential pricing, rational farmers will shift acreage away from pulses and oilseeds toward the more lucrative energy crop. This doesn't need to be a conscious policy choice — it happens automatically through price signals.

The workable middle path has four elements. First, restrict CBG feedstock eligibility to waste streams (dung, crop residue, municipal waste, food waste, sewage) and prohibit or cap the use of dedicated food crops — the Denmark model. Second, delink ethanol pricing from feedstock type so that no single crop gets an artificial advantage. Third, strengthen MSP and procurement for pulses and oilseeds so that these crops remain competitive. Fourth, integrate the biogas push with the stubble burning policy — make paddy straw the primary feedstock in Punjab and Haryana, and cattle dung in Gujarat, Rajasthan, and UP, rather than creating new demand for maize or sugarcane.