Energy Techonologies - Biomass-based Power Generation

Introduction

India produces a huge quantity of biomass material in its agricultural, ago-industrial, and forestry operations. According to some estimates, over 500 million tonnes of agricultural and agro-industrial residue alone is generated every year. This quantity, in terms of heat content, is equivalent to about 175 million tonnes of oil. A portion of these materials is used for fodder and fuel in the rural economy. However, studies have indicated that at least 150-200 million tones of this biomass material does not find much productive use, and can be made available for alternative uses at an economical cost. These materials include a variety of husks and straws. This quantity of biomass is sufficient to generate 15000-25000 MW of electrical power at typically prevalent plant load factors. In addition, electricity can also be generated from biomass grown on wastelands, road and rail trackside plantations, etc. The quantum of electricity that can be produced from such biomass has been estimated to be in excess of 70, 000 MW. Thus, the total electricity generation potential from biomass could reach a figure of about 100, 000 MW.

The technology for generation of electricity from these biomass materials is similar to the conventional coal-based thermal power generation. The biomass is burnt in boilers to generate steam, which drives a turbo alternator for generation of electricity.

Advantages

• These projects can be designed to match the electric loads as biomass can be stored and used according to demand.
• Equipment for these projects is similar to that for coal-based thermal power projects and hence, no new technological developments are required.
• Due to their proximity to the rural areas, these projects are likely to improve quality of electricity supply there.
• A variety of biomass materials can be used in the same plant, providing flexibility of operations.

Technology and equipment

The technology for use of biomass for power generation is fairly well established in the country. The equipment required for these projects comprises mainly of boilers, turbines, and grid inter-phasing systems. Recent innovations include the use of air-cooled condensers to reduce consumptive use of water. All these items of equipment are available indigenously.

Achievements

A power-generation capacity of about 302 MW has been commissioned through 54 projects, as on March 2005. A further capacity addition of about 270 MW through 39 projects is reported to be under implementation. The biomass materials that have been used for power generation in these projects include rice husk, cotton stalk, mustard stalk, Prosopis juliflora (Vilayati babul), poultry litter, bagasse, cane trash, etc. State-wise distribution of the commissioned and 'under implementation' capacity is given in Table

State-wise list of commissioned and 'under implementation' biomass power capacity, as on 31 March 2005

Costs

Typical capital costs for biomass power projects range from Rs 3 crores/MW to Rs 4 crores/MW. Costs of generation depend upon the cost of biomass, the plant load factor, and the efficiencies of conversion.

Financial incentives

During 2003-04, the MNES offered financial support for biomass-based power projects, as detailed in Table5. These incentives have been continued for 2004-05 too, although they are subjects to change without prior notice. Information on the latest scheme of incentives can be obtained from the MNES website.

Financial support by the MNES for biomass-based power projects

Financing

Apart from the Indian Renewable Energy Development Agency (IREDA), many financial institutions now provide term loans for biomass-based power projects based on the merits of the projects. Among these financial institutions are the Power Finance Corporation (PFC), many nationalized banks, the IDBI, the ICICI, etc.

Main Application: Energy

Contact:

Ministry of Non-Conventonal Energy Sources,
Govt. of India
Block-14, CGO Complex, Lodi Road
New Delhi – 110 003
Tel: 91 11 2436 0707/ 2436 0404
Fax: 91 11 2436 1298

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