Fuel from Forests

Using pine needles and other biomass to generate electricity in Uttarakhand

By Anita Khuller

With an area spanning about 7.62 million hectares, the Himalayan subtropical pine forests are the largest in the Indo-Pacific region. In India, these pine forests are widely found in the state of Uttarakhand. As per the Uttarakhand Renewable Energy Development Agency (UREDA), the Chir Pine Forest in the state covers a total area of about 399,329 hectares (16.36 per cent of the total forest area in the state). Forest fires are quite common in these areas as pine needles, which are highly inflammable, keep falling off trees from the middle of March till the onset of the monsoon in July. This has a serious impact on the environment, leading to the loss of flora and fauna.

As per estimates, over 1.5 million metric tonnes (mmt) of pine litter is generated annually in the Reserve and Van Panchayat forests (excluding wildlife areas) in the state. Therefore, even if about 40 per cent of the estimated quantity is taken as collectible quantity, after making sufficient provisions for traditional uses, about 600,000 mmt is available for industrial use. Apart from pine litter, about 800,000 mmt of other biomass (agricultural crop residues, lantana, etc.) is also available in Uttarakhand for industrial purposes.

As per a GIZ study in 2014, a proximate analysis of seven different location samples concluded that pine needles contain 12-19 per cent fixed carbon, 1.5-3 per cent ash and 8-30 per cent moisture, which gives them an edge over rice husk and wood biomass. Meanwhile, the ultimate analysis highlighted its advantages as a fuel with carbon content of 50-55 per cent. The other parameters were within acceptable limits, barring sulphur, which exceeded the norm marginally. Despite high sulphur content, 17.8-20.8 megajoules (MJ) per kg of energy can be obtained from the feedstock of pine needles. An analysis of the producer gas composition shows that it is fit to be used in an internal combustion engine, and has a calorific value of 4-4.5 MJ per Nm3. The efficiency of the demonstration gasifier was nearly 75 per cent, and 20-22 per cent of char was produced with a heating value of 19.5 MJ per kg.

Based on these resources, the state has the potential of producing over 150 MW of energy annually from biomass-based projects of up to 250 kW and briquetting/bio-oil units of up to 2,000 mtpa. They can not only help meet the local energy needs, but can also be an effective means for livelihood/revenue generation.

The Uttarakhand Policy for Energy Generation from Pine Litter and Other Biomass – 2018 is applicable to pine litter and other biomass-based power generation and briquetting/bio-oil projects in the state. Its aim is to harness renewable energy resources in the state, enhance private sector and community participation in energy generation, mitigate forest fires caused by pine litter, create avenues for rural employment to prevent migration, and provide decentralised energy supply to the agricultural, commercial and household sectors as well as small-scale industries. The Forest Department and UREDA will act as nodal agencies for the implementation of this policy in the state.

Under the policy, 10 kVA and 25 kVA power generating units will be set up in Uttarakhand through state-based voluntary organisations, firms, industrial units, cooperative societies and community-based organisations. The 25 kVA power plants based on dry pine leaves will generate 140,000 units of electricity per annum and around 21,000 kg charcoal. Their sale will generate an income of Rs 930,000. As per Madan Kaushik, state urban development minister, around 6,000 such units can be established under the policy, which can give direct and indirect employment to around 60,000 people.

A 25 kVA dry pine needles power generating unit is set up at an estimated cost of Rs 2.5 million. It is mandatory for the beneficiaries to submit project proposals for setting up such plants by the end of 2019 to avail of a subsidy of Rs 18,000 per person. Those interested in setting up such plants will be entitled to an additional 30-60 per cent subsidy under the government’s Micro, Small and Medium Enterprises Policy. Subsidies will also be provided for setting up plants that use pine needles to produce bio-oil and briquettes. The state government will purchase the electricity generated by such plants at a minimum support price of Rs 5.36 per unit.

The maximum land allowed for power projects up to 100 kW will be around 1,000 square metres, and for projects of more than 100 kW and up to 250 kW the maximum land allowed will be 2,000 square metres. The minimum capacity allocated to each developer will be 10 kW and the maximum capacity will be 250 kW. However, there will not be any maximum capacity cap for project allocation to central and state government agencies/corporations.

For pine litter and other biomass-based energy generation capacity, the targets are 1 MW by 2019, 5 MW by 2021, and 100 MW by 2030. In addition, 50 biomass briquetting/bio-oil plants with a maximum capacity of 2,000 mtpa are targeted to be set up by 2030.

Since there is a need to remove pine litter from the forest floor on a regular basis in order to prevent fires, the government will pay Re 1 per kg to those who collect what is locally known as pirul from the jungles, and supply it to the plants. This could provide an additional source of income to women, who can do this part-time along with their regular household and agricultural duties.

In view of the tendency of pine needles to catch fire, it will be necessary to ensure that the stored raw material is transported from the storage area to the project location as soon as possible.

Other benefits

Apart from electricity generation, the high-energy-content residue of the biomass gasification process is briquetted into cooking charcoal using a locally available binder. The availability of charcoal at their doorstep has reduced the fuel gathering time of the villagers by 70 per cent. It has also provided a smoke-free environment to them. The residue from a 120 kW gasifier system will be sufficient to meet the cooking fuel needs of 100 households. People who are employed to collect pine needles are remunerated both in cash and cooking charcoal, thereby generating income for local people and saving the forests from being cut down. Avani Bio Energy, an NGO in Uttarakhand, has developed an efficient, inexpensive charcoal cookstove made entirely from locally available materials. Local people are trained to manufacture and repair the stoves, thus generating livelihoods.

Key challenges

To implement such projects, there is a need to address both collection and transportation challenges. The collection of pine needles involves carrying heavy loads over distances, typically up steep slopes. Further, the moisture content of pine needles reduces the efficiency and increases the maintenance requirement of the gasification system. Thus, there is a need to reduce the moisture content from 29-30 per cent to 15 per cent before feeding the pine needles into the gasifier.

The biggest challenge in handling and monitoring the performance of the gasifier is its bulk density of 187 kg per m3. Preprocessing helps increase the density to over 500 kg per m3, which increases the heating value considerably due to the increase in carbon monoxide content. Another recommendation is to slightly modify the gasifier vis-à-vis the hopper design, screw design, grate design, ash removal technique, etc.

Progress so far

As of date, the government has issued letters of award to 21 companies to set up such plants with a total production capacity of 675 kW, and has signed 12 agreements so far. Uttarakhand Power Corporation Limited (UPCL), the state power distribution company, will sign separate power purchase agreements (PPAs) with these companies to buy electricity at Rs 7.54 per unit. Chander Singh Bisht’s company, the Bhagirathi Chidh Vidyut Producer, is setting up the biggest pirul plant of 125 kW in Dunda block of Uttarkashi district.

In another development, the Uttarakhand Forest Department, in association with the Indian Institute of Technology Roorkee, is working on a project to produce coal from pine needles, which will help supplement the coal shortfall in the state.

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