Techno Economic Aspects of Power Generation From Agriwaste in India
Authors: Lonia B. , Nayar N. K. , Singh S. B. , Bali P. L. 
Published: January 2009

The agricultural operations in India are suffering from a serious problem of shortage of electrical power on one side and economic and effective disposal of agriwaste stuff on the other. India being agriculture based country, 70% of its main income (share in GDP) comes from agriculture sector. Any enhancement of income from this sector is based upon adequate supply of basic inputs in this sector. Regular and adequate power supply is one such input. But, the position of power supply in our country defies both these characteristics. With a major portion of power produced being sent to the industrial and urban consumers, there is a perennial shortage of power in the agriculture sector. Consequently, there is an emergent need to produce more power in order to fulfil the needs of this sector effectively. One way of accomplishing this is setting up captive, preferably rural based, small power generation plants. In these power plants, instead of water-head, diesel oil or coal, we can use agri-residue to produce electricity. One such power plant (1–2 MW capacity) can satisfy the power need of 25 to 40 nearby villages. The agriwaste like rice straw, sugarcane-trash, coir-pith, peanut shells, wheat stalks & straw, cottonseed, stalks and husk, soyabean stalks, maize stalks & cobs, sorghum. Bagasse, wallnut shells, sunflower seeds, shells, hulls and kernels and coconut husk, wastewood and saw dust can be fruitfully utilized in power generation. This stuff is otherwise a waste and liability and consumes a lot of effort on its disposal; in addition to being a fire and health hazard. Agriwaste stuff which at present is available in abundance and prospects of its utilization in producing energy are enormous. This material can be procured at reasonably low rates from the farmers who will thus be benefited economically, apart from being relieved of the responsibility of its disposal. Agri-residue has traditionally been a major source of heat energy in rural areas in India. It is a valuable fuel even in the sub-urban areas. Inspite of rapid increase in the supply of, access lo and use of fossil fuels, agri-residue is likely to continue to play an important role, in the foreseeable future. Therefore, developing and promoting techno-economically-viable technologies to utilize agri-residue efficiently should be a persuit of high priority. Though there is no authentic data available with regard to the exact quantity of agricultural and agro-industrial residues, its rough estimate has been put at about 350 mt per annum. It is also estimated that the total cattle refuse generated is nearly 250 mt per year. Further, nearly 20% of the total land is under forest cover, which produces approximately 50 mt of fuel wood and with associated forest waste of about 5 mt.(1). Taking into account the utilization of even a portion (say 30%) of this agri-residue & agro-industrial waste as well as energy plantation on one million hectare (mha) of wastelands for power generation through bioenergy technologies, a potential of some 18000 MW of power has been estimated. From the foregoing, it is clear that there is an enormous untapped potential for energy generation from agri-residue. What is required is an immediate and urgent intensification of dedicated efforts in this field, with a view to bringing down the unit energy cost and improving efficiency and reliability of agri-waste production, conversion and utilisation, leading to subsequent saving of fossil fuels for other pressing applications. The new initiatives in national energy policy are most urgently needed to accelerate the social and economic development of the rural areas. It demands a substantial increase in production and consumption of energy for productive purposes. Such initiatives are vital for promoting the goals of sustainability. cleaner production and reduction of long-term risks of environmental pollution and consequent adverse climatic changes in future. A much needed significant social, economic and industrial development has yet to take place in large parts of rural India; be it North, West, East or South. It can be well appreciated that a conscious management of agri-residue, which is otherwise a serious liability of the farmer, through its economic conversion into electric power can offer a reasonably viable solution to our developmental needs. This vision will have to be converted into a reality within a decade or so through dedicated and planned R&D work in this area. There is a shimmering promise that the whole process of harvesting, collection, transport and economic processing and utilisation of agri-waste can be made technically and economically more viable in future. Thus, the foregoing paras amply highlight the value of agri-residue as a prospective source of electric power, particularly for supplementing the main grid during the lean supply periods or peak load hours and also for serving the remote areas in the form of stand-alone units giving a boost to decentralised power supply. This approach and option seems to be positive in view of its potential contribution to our economic and social development. No doubt, this initiative needs to be backed and perused rigorously for removing regional imbalances as well as strengthening National economy. This paper reviews the current situation with regards to generation of agriwaste and its prospects of economic conversion into electrical power, technologies presently available for this purpose, and the problems faced in such efforts. It emphasizes the need for an integrated approach to devise ways and means for generating electrical power from agriwaste; keeping in mind the requirements of cleaner production and environmental protection so that the initiative leads to a total solution.