Government of India. Ministry of Non-Conventional Energy Sources. Biogas

Transcription

1 1 Government of India Ministry of Non-Conventional Energy Sources Biogas

2 Dr Manmohan Singh Prime Minister of India Smt. Sonia Gandhi Chairperson, National Advisory Council Energy is an important input for economic development. Since exhaustible energy sources in the country are limited, there is an urgent need to focus attention on development of renewable energy sources and use of energy efficient technologies. The exploitation and development of various forms of energy and making energy available at affordable rates is one of our major thrust areas. Today India is one of the few leading countries in the development and utilization of renewable energy. The country is blessed with various sources of non-conventional energy and I hope the efforts of Ministry of Non-Conventional Energy Sources will promote viable technologies that can reach the benefits of such sources to the poorest people in the far-flung regions of the country.

3 Renewable Energy in India Energy is a basic requirement for economic development. Every sector of Indian economy agriculture, industry, transport, commercial, and domestic needs inputs of energy. The economic development plans implemented since independence have necessarily required increasing amounts of energy. As a result, consumption of energy in all forms has been steadily rising all over the country. This growing consumption of energy has also resulted in the country becoming increasingly dependent on fossil fuels such as coal and oil and gas. Rising prices of oil and gas and potential shortages in future lead to concerns about the security of energy supply needed to sustain our economic growth. Increased use of fossil fuels also causes environmental problems both locally and globally. Against this background, the country urgently needs to develop a sustainable path of energy development. Promotion of energy conservation and increased use of renewable energy sources are the twin planks of a sustainable energy supply. Fortunately, India is blessed with a variety of renewable energy sources, the main ones being biomass, biogas, the sun, wind, and small hydro power. (Large hydro power is also renewable in nature, but has been utilized all over the world for many decades, and is generally not included in the term new and renewable sources of energy.) Municipal and industrial wastes can also be useful sources of energy, but are basically different forms of biomass.

4 R ENEWABLE ENERGY IN INDIA Advantages of renewable energy are that it is perennial available locally and does not need elaborate arrangements for transport usually modular in nature, i.e. small-scale units and systems can be almost as economical as large-scale ones environment-friendly well suited for decentralized applications and use in remote areas. The Ministry of Non-Conventional Energy Sources has been implementing comprehensive programmes for the development and utilization of various renewable energy sources in the country. As a result of efforts made during the past quarter century, a number of technologies and devices have been developed and have become commercially available. These include biogas plants, improved wood stoves, solar water heaters, solar cookers, solar lanterns, street lights, pumps, wind electric generators, water-pumping wind mills, biomass gasifiers, and small hydro-electric generators. Energy technologies for the future such as hydrogen, fuel cells, and bio-fuels are being actively developed. India is implementing one of the world s largest programmes in renewable energy. The country ranks second in the world in biogas utilization and fifth in wind power and photovoltaic production. Renewable sources already contribute to about 5% of the total power generating capacity in the country. The major renewable energy sources and devices in use in India are listed in Table 1 along with their potential and present status in terms of the number of installations or total capacity. 2

5 R ENEWABLE ENERGY IN INDIA Table 1 Renewable energy in India at a glance Cumulative Estimated installed capacity / Source/System potential number* Wind power MW 3595 MW Biomass power MW MW Bagasse cogeneration 3500 MW MW Small hydro (up to 25 MW) MW MW Waste to energy P Municipal solid waste 1700 MW 17 MW P Industrial waste 1000 MW MW Family-size biogas plants 12 million 3.71 million Improved chulhas 120 million million Solar street lighting systems Home lighting systems Solar lanterns Solar photovoltaic power plants 1566 kwp Solar water heating systems 140 million m 2 1 million m 2 of of collector area collector area Box-type solar cookers Solar photovoltaic pumps 6818 Wind pumps 1087 Biomass gasifiers MW * as on 31 March

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7 N ATIONAL ELECTRICITY POLICY 2005 National Electricity Policy 2005 The National Electricity Policy aims at achieving the following objectives. 1 Access to Electricity available for all households in the next five years. 2 Availability of Power demand to be fully met by Energy and peaking shortages to be overcome and spinning reserve to be available. 3 Supply of reliable and quality power of specified standards in an efficient manner and at reasonable rates. 4 Per capita availability of electricity to be increased to over 1000 units by Minimum lifeline consumption of 1 unit/household/day as a merit good by Financial turnaround and commercial viability of electricity sector. 7 Protection of consumers interests. The Electricity Act 2003 The Electricity Act contains the following provisions pertaining to nonconventional energy sources. Sections 3(1) and 3(2) Under Sections 3(1) and 3(2), it has been stated that the Central Government shall, from time to time, prepare and publish the National Electricity Policy and Tariff Policy, in consultation with the state governments and authority for development of the power system based on optimal utilization of resources such as coal, natural gas, nuclear substances or material, hydro and renewable sources of energy. 5

8 T HE ELECTRICITY ACT 2003 Section 4 Section 4 states that the Central Government shall, after consultation with the state governments, prepare and notify a national policy, permitting stand-alone systems (including those based on renewable sources of energy and other non-conventional sources of energy) for rural areas. Section 61 Section 61, 61(h) and 61(i) state that the appropriate commission shall, subject to the provision of this Act, specify the terms and conditions for the determination of tariff, and in doing so, shall be guided by the following, namely, the promotion of cogeneration and generation of electricity from renewable sources of energy; and the National Electricity Policy and Tariff Policy. Section 86(1) Section 86(1) and 86(1)(e) state that the state commissions shall discharge the following functions, namely, promote cogeneration and generation of electricity from renewable sources of energy by providing, suitable measures for connectivity with the grid and sale of electricity to any person, and also specify, for purchase of electricity from such sources, a percentage of the total consumption of electricity in the area of a distribution license. 6

9 Biogas Biogas represents an alternative source of energy, derived mainly from organic wastes. In India, the use of biogas derived from animal waste, primarily cow dung, has been promoted for over three decades now. According to the 1997 Livestock Census, the cattle population in the country is about 290 million. The estimated potential of household biogas plants based on animal waste in India is 12 million. Till December 2004, under the National Biogas Programme, over 3.7 million biogas plants in the capacity of 1 6 m 3 had been installed. Larger units have also been set up in many villages, farms, and cattle houses. The estimated biogas production from these plants is over 3.5 million m 3 per day, which is equivalent to a daily supply of about 2.2 million m 3 of natural gas. These plants usually provide gas for cooking and lighting, the latter through specially designed mantles. By replacing up to 75% Utility of cattle dung through biogas plant

10 B IOGAS of the diesel in dual-fuel engines with biogas, mechanical and electrical power is also generated. Efforts are now under way to introduce smallcapacity engines to efficiently generate electricity from biogas in a decentralized mode. Standardized models of biogas plants suitable for individual households and institutions/communities are thus available. Along with development of plants and related infrastructure, a large pool of skilled manpower has been trained and deployed for plant construction and maintenance. The technology involved anaerobic digestion has been successfully extended to treat industrial and urban wastes on a large scale. This holds potential as a solution to numerous environmental problems, including waste and manure handling, water pollution, and carbon dioxide emission. Biogas Technology Biogas is a clean fuel produced through anaerobic digestion of a variety of organic wastes: animal, agricultural, domestic, and industrial. Anaerobic digestion comprises three steps. Decomposition (hydrolysis) of plant or animal matter to break down complex organic materials into simple organic substances Conversion of decomposed matter into organic acids Conversion of acids into methane gas As the process temperature affects the rate of digestion, it should be maintained in the mesophilic range (30 C 40 C) with an optimum of 35 C. It is also possible to operate plants in the thermophilic range (55 C 65 C) under controlled conditions. Apart from temperature, the rate of biogas production also depends on factors such as the carbon : nitrogen ratio, hydraulic retention time, solid concentration, and types of feedstock. Biogas consists of methane, carbon dioxide, and traces of other gases such as hydrogen, carbon monoxide, nitrogen, oxygen, and hydrogen sulphide. The gas mixture is saturated with water vapour and may contain dust particles. The relative percentages of these gases depend on the quality of feed material and the process conditions. The 8

11 B IOGAS percentage of methane in the gas determines its calorific value as the other constituents do not contribute to the energy content. The methane content of biogas is appreciably high, at 60%. This provides a calorific value high enough to find use in many energy applications, including power generation. Table 1 provides a comparison of the calorific values of various fuels. Table 1 Comparison of the calorific values of various fuels Fuel Calorific value (approximate) Natural gas 8600 kcal per m 3 Liquefied petroleum gas Kerosene Diesel kcal per kg kcal per kg kcal per kg Biogas 5000 kcal per m 3 Components of Biogas Plants Mixing tank The feed material (dung) is collected in the mixing tank. Sufficient water is added and the material is thoroughly mixed till a homogeneous slurry is formed. Inlet pipe The substrate is discharged into the digester through the inlet pipe/tank. Digester The slurry is fermented inside the digester and biogas is produced through bacterial action. Gas holder or gas storage dome The biogas gets collected in the gas holder, which holds the gas until the time of consumption. Outlet pipe The digested slurry is discharged into the outlet tank either through the outlet pipe or the opening provided in the digester. Gas pipeline The gas pipeline carries the gas to the point of utilization, such as a stove or lamp. 9

12 B IOGAS Types of Biogas Plants Fixed-dome type The fixed-dome biogas plant consists of one lower segment (for the digester) and a hemisphere over it (for both digester and gas holder). The mixing tank is connected to the digester by a 15-cm asbestos cement pipe. Through the outlet hole provided in the digester, the slurry is pushed into the outlet tank and overflows through another hole provided in the outlet tank. Floating-drum type The floating-drum biogas plant consists of a deep well-shaped underground digester connected by inlet and outlet pipes. A mild-steel gas storage drum, inverted over the slurry, rises and falls around a guide pipe corresponding to the accumulation and withdrawal of gas. Bag type Made of rubberized nylon fabric, the bag-type biogas plant is a portable unit, which can conveniently be placed at any location. The appropriate model is selected on the basis of technical requirements such as location, distance between 10

13 B IOGAS kitchen and cattle shed, availability of dung and water, preferences of the beneficiaries, and so on. Table 2 lists the model household biogas plants and appliances approved for promotion under the National Biogas Programme. Table 2 Model household biogas plants/appliances approved for promotion under the National Biogas Programme Model Design guidelines Fixed-dome biogas plant 1 Deenbandhu model with brick Code of Practices (Second Revision), masonry IS 9478:1989 of the BIS, New Delhi 2 Deenbandhu ferrocement model MNES letter No.13-11/99-BG, dated with in-situ technique 5 March Pre-fabricated RCC fixed-dome MNES letter No.13-10/96-BG, dated model 10 January 2002 Floating drum biogas plant 1 KVIC floating metal drum type Code of Practices (Second Revision), IS 9478:1989 of the BIS, New Delhi 2 KVIC type plant with ferrocement Code of Practices IS-12986:1990 of digester and fibre glass reinforced BIS, New Delhi plastic gas holder 3 Pragati model Code of Practices (Second Revision), IS 9478:1989 of the BIS, New Delhi Bag-type biogas plant Flexi model MNES letter No.7-39/89-BG dated 14 July 1995 Appliances ISI marked (BIS code IS : 1988) burners with minimum 55% thermal efficiency 11

14 B IOGAS Standard Capacity For family-type biogas plants, approved models are available for 1 6 m 3 and 1 10 m 3 capacities for fixed-dome and floating-drum plants, respectively. The commonly used capacities of these models are 1 4 m 3. Applications Cooking Biogas can be used for cooking in a specially designed burner. A biogas plant of 2 m 3 capacity is sufficient for providing cooking fuel to a family of four to five. Lighting Gas lamps can be fuelled by biogas. To power a 100 candle lamp (60 W), the biogas required is 0.13 m 3 per hour. Power generation Biogas can be used to operate a dual-fuel engine and can replace up to 75% of the diesel. Biogas Digested Slurry The use of biogas digested slurry as organic manure can supplement the usage of chemical fertilizers. The effluent manure does not produce any odour and hence does not create any pollution. The biogas slurry is rich in nitrogen, the essential nutrient for plant growth. Moreover, this nitrogen is in water-soluble form and can be easily absorbed by the plants. 12

15 B IOGAS Efficiency of energy conversion from cattle dung The biogas slurry can also be mixed with biomass and composted. The slurry being full of bacteria (which can break down vegetable matter) makes excellent composting material. When a large mass of biomass waste with high carbon : nitrogen ratio is available, the slurry helps stimulate decomposition by acting as a nitrogen primer. Earthworms could either be cultured in dry sludge or in a compost pit. Benefits Provides a non-polluting and renewable source of energy Efficient way of energy conversion (saves fuelwood) Saves women and children from drudgery of collection and carrying of firewood, exposure to smoke in the kitchen, and time consumed for cooking and cleaning of utensils Produces enriched organic manure, which can supplement chemical fertilizers Leads to improvement in the environment, and sanitation and hygiene Provides a source for decentralized power generation Leads to employment generation in the rural areas 13

16 B IOGAS Table 3 The average estimated cost of the most popular Deenbandhu model Plant capacity Cost per plant 1 m 3 Rs m 3 Rs m 3 Rs m 3 Rs Cost The cost of installation varies according to the model and size of the plant. The average estimated cost of the most popular Deenbandhu model is given in Table 3. The cost of a biogas plant increases by about 30% in hilly areas and by 50% 60% in the north-eastern region of the country. Cost-effectiveness The lifespan of a biogas plant is estimated to be over 15 years. However, taking into account the utilization pattern, socio-economic aspects, and climatic factors, the practical average life of family-type biogas plants installed in the country may be estimated at about 10 years. Based on a life-cycle analysis, the cost estimated for generation of 1 m 3 biogas from a familytype biogas plant is Rs 3. A comparison of cost with diesel and kerosene based on energy value shows that biogas is cost-effective. It is estimated that the construction of 1 million biogas plants generates about 30 14

17 B IOGAS million man-days of employment for skilled and unskilled workers and 1.2 million tonnes of organic manure per year. Anaerobic digestion of cow dung and effective utilization of biogas also substantially contribute to the abatement of greenhouse gas emissions. Strategy for Promoting the Technology The MNES provides central financial assistance for construction and maintenance of biogas plants, development of skilled manpower, training for use and maintenance, awareness creation, and support to implementing agencies and technical centres for implementation of the programme. Financial Incentives Under the National Biogas Programme, central subsidy is available to users of different categories and areas for setting up biogas plants (Table 4). Provision of Loans The Reserve Bank of India and the National Bank for Agriculture and Rural Development (NABARD) support the biogas programme. Detailed guidelines are available with both commercial and cooperative banks for financing family-type biogas plants under the Agricultural Priority Area. NABARD provided automatic refinancing facility to commercial banks for loan amounts disbursed for biogas plants. Repair and Servicing Facility The government pays a job fee of Rs 800 per biogas plant constructed on turnkey basis with three years warranty for trouble-free functioning of the plant in north-eastern states, Sikkim, Jammu and Kashmir, Himachal Pradesh, Uttaranchal, hilly districts, and islands. In other regions, it is Rs 700 per plant. Financial support limited to 50% of the rate of central subsidy is also provided for repair and revival of family- 15

18 B IOGAS Table 4 National Biogas Programme: central subsidy for different categories and areas for setting up biogas plants Category/Area Central subsidy per plant North-eastern states and Sikkim Rs (except plain areas of Assam) Plain areas of Assam Rs 9000 Jammu and Kashmir, Himachal Pradesh, Rs 4500 (restricted to Uttaranchal (excluding Terai region), Nilgiris Rs 3500 for 1 m 3 fixed of Tamil Nadu, Sadar Kurseong and dome type) Kalimpong sub-divisions of Darjeeling, Sunderbans, Andaman and Nicobar Islands Scheduled Caste, Scheduled Tribe, desert Rs 3500 (restricted to districts, small and marginal farmers, landless Rs 2800 for 1 m 3 fixed labourers, Terai region of Uttaranchal, dome type) Western Ghats and other notified hilly areas All others Rs 2700 (restricted to Rs 2100 for 1 m 3 fixed dome type) type biogas plants, which are at least five years old and have developed structural defects thereafter. Programme Implementation and Training Support The programme is mainly implemented by the state governments, directly or through their designated agencies. The Khadi and Village Industries Commission is also designated as a national implementing organization. For installation of biogas plants, the block or district office or state headquarters of the concerned nodal agency may be contacted. Training is integral to the National Biogas Programme. Training programmes for construction, maintenance, and use of biogas plants are regularly organized by the implementing agencies with central 16

19 B IOGAS financial assistance. The quantum of central financial assistance provided for various training programmes is given in Table 5. Biogas development and training centres established in various parts of the country (Box 1) also provide technical training and publicity support for the programme. Table 5 Financial support for training courses Training course/ Duration Number of trainees CFA* per course Target audience (days) per course (Rs) Users Staff Refresher/constructioncum-maintenance Turnkey workers 21 days *central financial assistance Box 1 Biogas development and training centres College of Technology and Agricultural Engineering Maharana Pratap University of Agriculture and Technology Udaipur Department of Bio-Energy Agricultural Engineering College and Research Institute Tamil Nadu Agricultural University Coimbatore Department of Agricultural Engineering Himachal Pradesh Krishi Vishvavidyalaya Palampur Chemical Engineering Department Indian Institute of Technology Kharagpur Department of Agricultural Engineering University of Agricultural Sciences GKVK, Bangalore Department of Civil Engineering Punjab Agricultural University Ludhiana Centre of Energy Studies and Research Devi Ahilya Vishwavidyalaya Khandwa Road, Indore Planning Research and Action Division State Planning Institute Uttar Pradesh, Kalakankar House Lucknow College of Home Science GB Pant University of Agriculture and Technology, Pantnagar

20 B IOGAS Some basic information Cattle population in the country Availability of cowdung Availability of animal wastes Cow Calf Buffalo Pig Gas production per kg of wet dung 289 million (Livestock census:1997) 200 million tonnes 10 kg/day 5 kg/day 15 kg/day 2 kg/day 0.04 m 3 /day Biogas requirement for various applications For cooking m 3 per day per person For lighting 0.12 m 3 per hour per 100 candle power light For electricity generation through 0.6 m 3 per kwh dual-fuel engine For electricity generation through 0.75 m 3 per kwh 100% biogas engine 18

21 B IOGAS Rajiv Gandhi Akshay Urja Diwas On 20 August 2004 the 60th Birth Anniversary of our Late Prime Minister Mr Rajiv Gandhi the Ministry organized the Rajiv Gandhi Akshay Urja Diwas. Initiated by the Hon ble Minister of State (Non- Conventional Energy Sources), Mr V Muttemwar, the occasion saw the release of a commemorative stamp by the Hon ble Prime Minister, Dr Manmohan Singh, at a function attended by Smt. Sonia Gandhi, Chairperson, United Progressive Alliance (UPA), Members of the Union Cabinet, Members of Parliament, Chief Ministers, Foreign Dignitaries, Administrators, Scientists, and students among others. The day was also appropriate to advocate renewable energy, since Mr Rajiv Gandhi was a keen enthusiast of scientific advances that would enable India to leap into the 21st century. Thus, a human chain of nearly school children was formed in the National Capital to promote a renewable future. In the rest of the country too, functions such as rallies and human chains were organized. In addition, competitions such as essay writing, painting, quizzes, and debates were held, all of which covered different aspects of renewable energy from biogas to biomass to solar, hydro, and wind power. The essence of these public activities was to generate mass awareness and disseminate information about the advances made in renewable energy technologies, and with the ultimate objective of achieving Akshay urja se desh vikas Gaon gaon bijlee, ghar ghar prakash. The success of the Rajiv Gandhi Akshay Urja Diwas has encouraged the Ministry to make it an annual affair, to be celebrated on 20 August every year. 19

22 B IOGAS For more information, please contact Ministry of Non-Conventional Energy Sources Block No. 14, CGO Complex Lodi Road, New Delhi Tel Fax Disclaimer Every effort has been made to provide correct information in this booklet. However, the Ministry of Non-Conventional Energy Sources (MNES) does not assume any responsibility for the accuracy of the facts and figures mentioned here, nor for any consequences arising out of use of any information contained in this publication. 20

23 Shri Vilas Muttemwar Minister of State (Independent Charge) Non-Conventional Energy Sources, Government of India New Delhi The promotion of renewable energy sources in the country requires widespread publicity and greater awareness of the potential of these energy sources and the products available. The Ministry of Non- Conventional Energy Sources is expanding several of its programmes so that these sources can contribute to sustainable development of the nation. The Ministry will work towards reducing the costs of renewable energy products and making them easily available to the people. The motto of the Ministry is Akshay urja se desh vikas and the ultimate goal is Gaon gaon bijli, ghar ghar prakash.

24 1 Biogas Booklets in this Series 1 Biogas 2 Biomass 3 Solar Heat 4 Solar Electricity 5 Energy Recovery from Wastes 6 Wind Energy 7 Small Hydro Power 8 Hydrogen Energy 9 Solar Energy Centre 10 Centre for Wind Energy Technology 11 Indian Renewable Energy Development Agency Ltd 12 Information and Public Awareness Ministry of Non-Conventional Energy Sources, Government of India Block No. 14, CGO Complex, Lodi Road, New Delhi Web site: