Sourcing Renewable Energy from Stubble

Context

• The beginnings of a renewable energy revolution rooted in agriculture is taking shape in India with the first bio-energy plant of a private company in Sangrur district of Punjab having commenced commercial operations recently.
• It will produce Compressed Bio Gas (CBG) from paddy straw, thus converting agricultural waste into wealth.

Problem of Stubble

• It has become a common practice among farmers in Punjab, Haryana and western Uttar Pradesh to dispose of paddy stubble and biomass by setting it on fire to prepare fields for the next crop, which has to be sown in a window of three to four weeks. 
• The resultant clouds of smoke engulf the entire National Capital Territory of Delhi and neighbouring States for several weeks between October to December. This plays havoc with the environment and affects human and livestock health.

About Stubble burning

• Stubble burning:
  • It has become a common practice among farmers in Punjab, Haryana and western Uttar Pradesh to dispose of paddy stubble and biomass by setting it on fire.
    • It is spread over millions of hectares. 
  • Why?
    • This is done to prepare fields for the next crop, which has to be sown in a window of three to four weeks.
• Issues:
  • Pollution:
    • This stubble burning results in the formation of clouds of smoke engulfing the entire National Capital Territory of Delhi and neighbouring States for several weeks between October to December. 
  • Health hazards:
    • This plays havoc with the environment and affects human and livestock health.
    • The pollution makes people more vulnerable to infection and slows their recovery post-infection.
  • Affects soil:
    • Burning husk on the ground destroys the nutrients in the soil, making it less fertile.
    • Heat generated by stubble burning penetrates into the soil, leading to the loss of moisture and valuable microbes.

• Government measures:
  • The Government of India has put in place several measures and spent a lot of money in tackling the problem. 
    • The Commission for Air Quality Management in National Capital Region and Adjoining Areas (CAQM) had developed a framework and action plan to prevent and control stubble burning effectively. 
    • In-situ management:
      • The framework/action plan includes in-situ management, i.e., incorporation of paddy straw and stubble in the soil using heavily subsidised machinery (supported by the crop residue management (CRM) Scheme of the Ministry of Agriculture and Farmers Welfare). 
    • Ex-situ CRM efforts include:
      • The use of paddy straw for biomass power projects and co-firing in thermal power plants, and as feedstock for 2G ethanol plants, feedstock in CBG plants, fuel in industrial boilers, waste-to-energy (WTE) plants, and in packaging materials, etc.
    • Prohibition on stubble burning:
      • Additionally, measures are in place to ban stubble burning, to monitor and enforce this and initiate awareness generation. 
  • Despite these efforts, farm fires continued unabated.
• Challenges:
  • Though paddy stubble burning in northwest India has received a lot of attention because of its severity of pollution.
  • Although the reality is that crop residue burning is spreading even to rabi crops and the rest of the country. 
  • Unless these practices are stopped, the problem will assume catastrophic proportions.

Using stubble for energy generation

• Producing CBG and pellets:
  • A techno-economic assessment of energy technologies suggested that rice straw can be cost-effective for producing CBG and pellets. 
    • Pelletisation: 
      • Pelletisation means converting paddy straw into pellets which can be used in thermal power plants and industries as fuel.
      • Pellets can be used in thermal power plants as a substitute of coal 
    • Compressed Bio-Gas (CBG): 
      • CBG can be generated from the stubble which in turn will be used as a transport fuel. 
• Significance:
  • Wealth from waste:
    • Paddy straw from one acre of crop can yield energy output (CBG) worth more than ?17,000 — an addition of more than 30% to the main output of grain. 
    • This initiative is an ideal example of a ‘wealth from waste’ approach and circular economy.
  • Meeting STAT targets:
    • With 30% of the rice straw produced in Punjab, a 5% CBG production target set by the Government of India scheme, “Sustainable Alternative Towards Affordable Transportation (SATAT)” can be met. 
  • Producing compost:
    • The slurry or fermented organic manure from the plant (CBG) will be useful as compost to replenish soils heavily depleted of organic matter, and reduce dependence on chemical fertilizers. 
  • Boost to the local economy:
    • The plant will also provide employment opportunities to rural youth in the large value chain, from paddy harvest, collection, baling, transport and handling of biomass and in the CBG plant. 
    • This will boost the economy of Punjab. It is pertinent to mention that straw from many other crops contains higher energy than paddy straw.

Other Alternatives to Stubble Burning

• Using stubble as a mulch:
  • One such method is using a Turbo Happy Seeder (THS) machine, which can uproot the stubble and also sow seeds in the area cleared. The stubble can then be used as mulch for the field.
• Bio- decomposition:
  • Another possible alternative is the Pusa bio-decomposer, developed by scientists at the Indian Agricultural Research Institute, which turns crop residue to manure in 15-20 days by accelerating the decomposition process.
• Changing cropping pattern: 
  • It is the deeper and more fundamental solution.