Biomass: Turning Agricultural Waste to Green Power in India

India’s past reliance on coal based thermal power is a serious environment concern with the increasing awareness about global warming so the Government is actively encouraging green power. It has been estimated that if all of India’s agricultural wastes were used for power generation it could potentially generate over 50,000 MW of power while simultaneously giving very valuable extra income to farmers. Special report on biomass from Murad Baig in India

BIOMASS – FAST TRACK TO CLEAN AND GREEN POWER

Although the Indian government is taking urgent action to accelerate its power production, power demand continues to grow at an exponential rate to keep outpacing the available sources. Faster economic growth rates not only encourages industrial and housing growth but also increases consumer spending on computers, refrigerators, TV’s, air-conditioners, washing machines and other energy demanding appliances both in urban and rural areas.

India’s past reliance on coal based thermal power is also a serious environment concern with the increasing global awareness about global warming so the Government is actively encouraging green power. Hydro power projects are slow but a number of wind power projects are moving rapidly and several nuclear power projects in the public and private sector are being developed after the international sanctions were removed.

Biomass potential

The most widely available and also the most wasted energy source are a wide variety of agricultural wastes. While some of it is used for cattle fodder huge amounts of paddy straw, cane trash and other farm wastes are simply burned in the fields unlike wheat straw that is completely utilised as fodder. After China, India is the world’s largest producer of paddy. India now produces 98 million tonnes of paddy with roughly 130 million tonnes of straw of which only about half is used for fodder. India also produces about 350,000 tonnes of cane that will yield about 50 million tonnes of cane trash that is also an excellent biomass fuel. With high silica content it has no commercial use and is therefore almost entirely burned. Other agro wastes are maize, cotton, millets, pulse, sunflower and other stalks, bull rushes (sirkanda), groundnut shells, coconut trash, etc., all make good biofuels. The farmers with time constraints to their crop cycles have to burn huge quantities of biomass that contributes to great haze and global warming.

It has been estimated that if all these agro wastes were collected and used for power generation it could potentially generate over 50,000 MW of power while simultaneously giving very valuable extra income to farmers. 120,000 tonnes of paddy straw that each 12 MW plant typically needs will be collected from roughly 15,000 farmers who stand to earn an incremental income of about Rs. 500 an acre or Rs, 2,500 for an average Punjab farmer with about 5 acres. So each project can give the local farmers extra income of roughly Rs. 4 Crores.

It is only quite recently that biomass power has been taken seriously world-wide as there were problems in biomass collection in short seasons and a few technical modifications necessary in the boiler technology. Recognizing the huge potential of biomass the Indian government has enacted several new initiatives to accelerate biomass power production offering higher tariffs than for thermal projects. As biomass projects are also carbon neutral they are eligible to earning valuable carbon credits.

Another big advantage of biomass power projects is that they are relatively small, in the 10 – 25 MW range, and have to be located in widely scattered rural areas. Thus the power they generate can be fully consumed in nearby areas resulting in much lower transmission losses. With modest investments in the Rs. 50 – 100 Crore range, a number of biomass power plants therefore can be set up in as little as 12 months from first brick to first unit of generated power. (The first project, like all pioneering projects, however faced numerous delays owing to many new clearances and was affected by several changes in the local government).  

Considerable quantities of paddy and other agro products are harvested by India’s existing fleet of about 30,000 combine harvesters. While these efficiently collect the grain it throws out broken straw that is mostly considered useless. The fleet of balers attached to each plant can efficiently collect this and make compact bales suitable for efficient storage and handling.

Fuel collection is however a serious issue and a fleet of 100 tractor towed balers costing nearly Rs. 7 Crores are needed to collect the broken straw dropped by the combine harvesters in a short period of 6 – 8 weeks between the Kharif (paddy) harvest and the Rabi (wheat) sowing.

Each plant requires about 120,000 tonnes of biomass per year (Roughly 350 tonnes per day). The collected straw has to be stored in a number of stockyards rented from farmers in a 15 Km radius around the plants. Each fuel centre has a weighbridge and fire management systems. A fleet of 30 tractors and trailers are also needed to transport about 100 loads of straw daily from the fuel depots to the plants. These increase the fuel costs but they are still quite attractive as viable sources of green energy.

Bermaco Group biomass power projects

Bermaco Energy Systems has been in the power sector for over three decades first as a supplier of boilers and other power plant equipment. It had completely built a 165 MW power plant as well as installed nearly thirty units of 10 – 25 MW gas turbine power plants. In the biomass area it had earlier leased an existing 10 MW biomass plant in Punjab for several years. Although this old plant had several technological deficiencies, it proved the viability of a project based on paddy straw.

Punjab Biomass Power Ltd., a 50:50 joint venture between Bermaco Group and Gammon Infrastructure Projects Limited, has just completed a 12 MW plant near village Ghanaur in the Patiala district of Punjab. The financial closure was facilitated by the Power Finance Corporation. This project mainly uses paddy straw (not paddy husk that is already widely used as an expensive commercial fuel).

The Plant configuration is as follows; – 67 Bar, 60 TPH, 430 Deg C traveling grate boiler, 12 MW bleed-cum-condensing steam turbine.

The furnace and boiler has had to be especially modified to be able to generate steam at the high temperatures necessary for good plant efficiencies.

The feeding of fuel is by a long belt conveyor after a set of small machines cut open the bales and shred the straw into small pieces to ensure uniform combustion. The turbine is conventional as also the water treatment, evacuation and other plant elements. An electrostatic precipitator ensures minimal atmospheric pollution.

Bermaco Group has also initiated several projects in developing green fuel with fast growing varieties of trees and high yielding bamboos to create energy farms that can augment biomass sources.

Although there will be some emissions from the burning process itself the project will earn substantial carbon credits as the complete carbon cycle is calculated from the oxygen generated by the rice, or other plants, while it is growing until it is finally burned. 

This will be the first of 9 similar projects in Punjab. Bermaco–Gammon Consortium plans to also set up 6 similar projects in the Haryana.

The Bermaco Group plans to set up 26 similar projects in Bihar to be followed by a number of projects in other states in a number of joint ventures with Power Trading Corporation, IL&FS and other corporate entities.      

Bermaco is planning to set up about 20 biomass power plants generating about 300 MW during the next three years and about 1,000 MW during the next six years. Bermaco believes that biomass power plants can be set up easily in most districts of India and that as they are all located in rural areas will directly benefit the rural communities. Bermaco believes that biomass power is the best way to quickly generate power that is clean and green.

Thermal power from coal, gas and oil currently accounts for about 70 % of India’s power generation of nearly 150,000 MW. Hydro power projects provide about 20% of India’s power and nuclear power accounts for 3% of India’s power. Wind energy currently accounts for about 5% of India’s power but is mainly confined to south India. Solar power projects despite high capital costs are being implemented. 

As compared to these, biomass power plants have modest capital costs and are much quicker to commission. Their fuel costs are manageable but huge human management effort is needed to collect, store, transport the fuel from farms to the depots and then to the plants. As India has huge agro wastes these medium sized projects can most quickly augment India’s power generating capacity in most rural areas of the country.

Murad Baig is a veteran New Delhi-based Journalist who regularly writes for Times of India. He has devoted years of his life to writing about cars and the automobile industry. He is following developments in India’s move to clean energy.

Source: www.abccarbon.com