By Dr A.R. Shukla, President, Indian Biogas Association, and Former Adviser, Bioenergy, MNRE
Stubble burning is one of the main causes of the severe pollution in the National Capital Region in the months of October and November every year. In the summer months as well, wheat straw burning in fields causes air pollution. The problem of air pollution is becoming unmanageable, not only in Delhi, but also in all other major cities in the country. The Supreme Court has issued directions to handle the situation as the air quality index has become unbearable. The grave situation of air pollution was also discussed in Parliament and serious efforts are being made to find solutions to fight this menace. A long-term solution for stubble burning will be to promote the bioenergy segment by floating appropriate policies for the collection and disposal of waste, and setting up a separate grid for compressed biogas (CBG) and piped natural gas (PNG) to integrate bioenergy.
Reasons for stubble burning
Agricultural practices today have changed drastically. Traditionally, all agricultural produce was utilised to meet various needs. The wood produced on farmlands and adjoining forests was used for making agricultural implements like carts and houses. The woody agro-waste was used as a fuel for cooking and heating. The crop waste was used as fodder for rearing different types of cattle, which were in turn used for transportation, pumping water, and production of milk and milk products required by humans. The cattle dung produced in the process was sent to farms as organic fertiliser. This way the woody and agro biomass waste was consumed and removed from the fields immediately after harvesting and well before sowing the next crop. Thus, a natural cycle was in place in entire agricultural operations. In the current scenario, cattle have been replaced by diesel- petrol- and electricity-operated agricultural appliances. As a result, a huge quantity of agricultural waste is left unutilised. This surplus also cannot be used as better and subsidised cooking fuels such as LPG and grid electricity are available.
Solutions
The situation created due to modern agricultural operations calls for a policy on the handling, disposal and utilisation of agro-biomass and cattle waste and its conversion to bio-CNG and organic fertilisers. A well-crafted policy is required as there are many challenges in waste collection and storage. While the cattle and biomass waste from agro-food processing industries and sugar mills is available on a continuous basis, the availability of all other types of biomass waste such as rice and wheat straw is seasonal. This increases the cost of agro-biomass waste collection, bailing, handling, transportation and storage. These costs have to be incurred to ensure the continuous availability of raw material throughout the entire year.
As the raw material costs of biomass plants are higher than those of solar and wind power plants, the policy should also define a price for purchasing biomass waste. The Supreme Court suggested a purchase price of Re 1 per kg, which can incentivise farmers to not burn the agricultural waste. Moreover, there has to be a definite guideline in the policy for the use of different types of biomass waste in different technology options. The lowest-cost bioenergy technology option capable of producing both organic fertilisers and bioenergy should be selected.
It is to be kept in mind that biomass waste will always have limited availability on account of production constraints due to land availability issues and seasonal dependence in different parts of the country. Therefore, policy initiatives alone will not help. There is a need to set up decentralised biogas, biomethane and bio-CNG plants in villages, and an integrated CBG and PNG grid across the country to ensure the evacuation and integration of the energy produced.
The establishment of an integrated CBG and PNG grid is technically feasible, and it can be made economically viable if the central government can arrange finances through the National Clean Energy and Environment Fund. The government can also aggregate various funds that have been set up by different ministries.
Conclusion
The issue of stubble burning is talked about every year but not much is done to eliminate the fundamental reasons that cause it. In my view, a long-term solution will be to incentivise farmers and developers to use agricultural waste to produce bioenergy. To achieve this, favourable policy and investments in grid infrastructure in rural areas will be necessary, along with the adequate availability of funds. If these suggestions are implemented, the government can not only solve the issue of stubble burning, but can also reduce the import bill on crude oils and create a robust rural agricultural economy.