- A recent study estimates the potential of crop residue availability, as a bioenergy resource in India.
- The study provides district and month-wise information as well as crop-specific surplus residue data which could assist in addressing bottlenecks in use of residue as biomass.
- Despite its ill effects on the environment and human health and efforts to counter it by the government of India and the Indian, burning of crop residue continues to be a prevalent practice, leading to pollutant emissions.
India’s potential to produce bioenergy from surplus crop residue is lower than previously estimated, claims a study. It suggests a potential of 1313 petajoules (PJ) (1 PJ= 277778 MWh) of bioenergy annually, lower than earlier estimates ranging from 1738 to 4150 PJ. However, the study provides valuable insights into the district and crop-specific bioenergy potential, which can help the country better plan and utilise the available resource.
The study conducted across India and supported by the Ministry of Environment, Forest and Climate Change (MoEFCC), noted prevalant burning of crop residue, which is the material left behind after harvest, of crops such as rice, wheat, sugarcane, maize, millets, groundnut, oilseed, cotton and banana. Crop residue burning is an easy, low-cost way to dispose residue. However, crop residue burning, leads to pollutant emissions and can instead be targetted as a bioenergy resource, indicates the study.
Sixteen institutes, including the Indian Institute of Technology (IIT) and Indian Institute of Science Education and Research (IISER) and others, collaborated on this study where researchers used the bottom-up approach (starting with a ground survey) of country-wide surveys to estimate the quantity of surplus crop residue being burned on the field. They used primary survey data from over 43 representative districts and secondary data related to cattle numbers, socio-economic variables, and satellite-derived information. Based on the finding, researchers created a model to extrapolate it to all 735 districts of India, reflecting both location-specific variability and seasonal availability.
The paper claims that the research findings are important for effectively utilising surplus biomass towards producing bio-energy while also controlling stubble burning to prevent air pollution.
The study estimates large bioenergy potentials from surplus residues in the districts of Punjab, Haryana, western Uttar Pradesh, central/western regions of Madhya Pradesh, Maharashtra and Gujarat. As per the study, rice (28%) and wheat (29%) are the largest contributors to surplus energy potential, followed by sugarcane (13%). The study indicates the months when bioenergy becomes available in each state. Most of the residue availability coincides with the rabi (March-May) and kharif (October–November) harvest periods. Some residues (such as sugarcane and banana) are available between December and February. Bioenergy availability is low in the country’s monsoon months (June–September).
Information on location, season and crop-specific biomass availability, provided by the study, could help overcome bottlenecks in the use of crop residue as a bioenergy resource in India.
Unlocking the potential
Biomass, a renewable energy source, is carbon neutral and has the potential to provide significant employment in rural areas, notes the study. The use of crop residue as a bio-energy resource helps achieve emission reduction targets which in turn improves air quality. Bioenergy can be harnessed in various forms, such as cofiring in coal power plants, independent thermal power plants (TPPs), combustion in cogeneration in sugar industries, biogas and bioethanol.
Despite the multiple benefits of biomass utilisation and the multitude of policy interventions, incidents of stubble burning have not been reduced significantly. Although the government reported around 30% decline in stubble-burning incidents during the kharif season, experts questioned the use of satellite data alone to give a clear picture of the change on the ground compared to last year.
Speaking to Mongabay India, Taveen S. Kapoor from IIT-Bombay, one of the lead authors of the study, said that farmers burn crop residue due to lack of utilisation, high expenses in removing the residue and transportation. There is presently no monetary value attached to the residues, which makes residue collection and transportation for using crop residue as a bioenergy resource, expensive.
A separate study conducted by the New Delhi-based non-profit Centre for Science and Environment (CSE) underlines the low usage of agro-residue (crop residue) and finds that not even 1% of the coal consumed yearly has been replaced with agro-residue in the eleven coal-based thermal power plants in the National Capital Region (NCR). The Ministry of Power (MoP) mandates thermal power plants to use 7% biomass pellets (densified form of farm stubble) along with coal.
This is when surplus residue is sufficient to meet the present mandate. “Our study shows that the present surplus can provide approximately 8% of the energy needs in the power plants. This will compel the system to find innovative solutions for the collection and transportation problems to reduce costs,” says Kapoor.
The research also suggests that the surplus use of biomass for cofiring in TPPs is presently limited because of high transportation costs, highlighting the importance of setting up plants for other technologies, such as biogas and bioethanol, closer to crop residue sources.
Kapoor believes that using the surplus crop residue in situ or near the generation of biogas/biofuel production plants is likely the best bet. Biogas/biofuel production plants can be set up to take residues from a cluster of villages. The produced fuels can be consumed within the villages, especially the biogas that can replace biomass-based cooking. Both ethanol and biogas can be blended with petrol and CNG, respectively.
To ensure that TPPs use the mandatory blending of biomass pellets, the MoEFCC, on July 14, issued a notification to enforce penalties on power plants that do not adhere to the mandatory blending rule.
Addressing the gap
In the last decade, union government has developed several policies to effectively utilise surplus biomass, especially to control stubble burning.
In November 2014, the Ministry of Agriculture came up with the National Policy for Management for Crop Residue (NPMCR). In January 2019, the MoEFCC launched the National Clean Air Programme (NCAP) as a long-term, time-bound, national-level strategy to tackle the air pollution problem nationwide. The NCAP identified agriculture crop residue burning in the Indo-Gangetic Plains as one major reason for air pollution. On October 8, 2021, the MoP issued the revised biomass policy mandating all TPPs in the country to use 5-7% of biomass pellets to cofire with coal. Apart from the MoP, the Commission on Air Quality Management (CAQM) has also directed TPPs located within 300 km of Delhi to initiate cofiring biomass-based pellets to curb air pollution from burning paddy straw. However, these efforts have not been able to push the usage of biomass.
Responding to the slow progress, Aggarwal further explains that the supply chain of agri-biomass is extremely tricky and difficult to scale up. All stakeholders (MOP, CAAQM, MoEFCC) are working together and came up with the SAMARTH (Sustainable Agrarian Mission on Use of Agri-Residue in Thermal Power Plants) portal in 2021. But there is a lack of coordination among authorities. TPPs and pellet manufacturers have their own stories to tell and blame each other.
Kapoor agrees that supply chain models for efficient utilisation of crop residues have been identified as essential information by previous research. While attaching a monetary value to the residue will enable farmers to cover costs for the mechanical collection of the residues from their fields.
Several factors affect the utilisation of surplus crop residue – seasonal availability, quality issues, logistics, a gap in demand and supply of biomass pellets, and the price of biomass pellets almost double domestic coal.
Recognising the multiple issues stakeholders face, MoP revised the Biomass Cofiring Policy in June 2023 to enable the purchase of biomass pellets by Power Plants at benchmark prices. The decision would encourage farmers, entrepreneurs, and thermal power utilities to strive to establish a sustainable biomass supply chain. The Ministry of New and Renewable Energy (MNRE), in its notification dated June 28, also introduced biomass-based production of green hydrogen target of 40,000 MT/annum under the incentive scheme of the National Green Hydrogen Mission.
Anubha Aggarwal, Programme Officer at the Industrial Pollution Unit at CSE, says it makes sense to use surplus biomass instead of coal, as the calorific value of biomass pellets is comparable to coal (when used in TPPs). It can also replace coal in other states, like the Delhi-NCR region, where a lot of industry has shifted to biomass fuel in different forms.
Aggarwal sees biomass not being quantified for multiple uses, such as TPPs, bio-CNG, bioethanol, and hydrogen, as one major bottleneck. “We are rampantly increasing our capacity for manufacturing pellets, bio-CNG, and bioethanol, without a clear idea of demand and surplus biomass availability in a region,” she says.
Regarding the latest research from IIT and other institutes, Kapoor further informs that better planning of crop residue management will also generate employment for the village residents and organic fertilisers as a by-product for local farms. Biogas plants can also use other materials such as cow dung, municipal solid waste, and food processing waste, which ensures a steady supply of raw material.
Banner image: A farmer checks the drip irrigation system system at his rice field in Govindapuram,Tamil Nadu, India. Rice and wheat are the largest contributors to surplus energy potential in India. Photo by by Hamish John Appleby for IWMI/Flickr.