Electricity Generation From Pine Needles

Dr. S. S. Verma, Department of Physics, S.L.I.E.T., Longowal, Distt.-Sangrur (Punjab)-148106

2018-04-27 07:45:21

Credit: pexels.com

Credit: pexels.com

There was a time in hills when governments put all round efforts in taking forestation activities to new heights in general and in hills in particular.  In the hills of Utrakhand and Himachal, whose climatic and geographical conditions are more suitable to the growth of pine trees were planted in large numbers.  Uttarakhand is home to more than 340,000 hectares of pine forests. Clubbed with stretches in western Nepal and Himachal Pradesh, pine forests cover about 1.5 million hectares. Pine trees grew to full-fledged forest 

areas in a very short time span.  The air coming from pine tree leaves is said to be very helpful to people suffering from Asthmas and tuberculosis.  The controlled wood from these pine trees were a great resource to local people for cooking, building materials and garniture and household wooden tools. 

Power of pine

However, the heaps of pine leaves were of no use except small amounts used for making brooms, cushion in animal homes as well as some amount as covers for particular crops in agriculture. At one hand, the large quantity of dry pine leaves are generally a great danger towards large forest fires which is very frequent scenes in pine tree forests. On the other hand, green pine leaves create a great inconvenience to human and animals to move safely through these highly slippery leaves as well as the thick cover of these leaves do not allow the grass and other vegetation to grow beneath.  With the changing times of civilization, there is always less importance given to hard work sensitive, innovative and sustainable methods of agriculture, drastic reduction in the practice of rearing animals, reduced use of cooking wood, and origin of highly resistant wood insects (e.g., termites) particularly in case of pine wood, use of pine tree wood, leaves and air is drastically getting very low. Moreover, pine tree forests as a cover to wild animals have become a great source of nuisance value and discomfort to the social system. It will be a welcome step if pine tree leaves can be used to generating electricity which will not only relieve the local people from this menace but also provide employment to local people. Thus a waste will become a source of wealth. The needle shaped leaves which keep falling off trees from the middle of March till the onset of the rains in July, are highly inflammable. It is considered by scientists and engineers to be experimented if pine needles could be used as biomass to generate electricity.

Pine as a resource

Using pine leaves as a biomass is difficult as pine needles make for such a loose biomass that they cannot be run through gasifiers, which convert biomass into combustible gases such as carbon monoxide, hydrogen and methane. In a small town about 100 km from Pithoragarh in hill state Uttarakhand, a company (Avani Bio Energy) is changing lives of locals with a unique project - generating power from pine needles. Company went with the idea of increasing the density of pine needles by converting them into wood like briquettes. That process was highly energy-intensive and so not viable. But he did not give up, and finally succeeded in setting up a plant that generates nine kilowatt of electricity. Company set up a gasifier and employs villagers to collect pine needles and bring them to the plant for which villagers get Rs 1,000 for every tonne of needles collected. The needles are chopped into fine pieces to increase density, before being fed into the plant. The material is then burnt with limited oxygen supply. This generates producer gas (a mixture of carbon monoxide, hydrogen and methane) which, after cleaning and cooling, is fed into a generator to produce electricity. One-tenth of the pine needles used as biomass comes out as charcoal - a by-product which can be used in place of wood and kerosene as cooking fuel.

Development status

Biological waste is being used to generate power for local people and the process even gives them employment. It was a small start but enough to attract the attention of some investors. Avani Bio Energy received $250,000 in funding from Acumen Fund, a non-profit venture fund. The money will help to set up 20 power plants with a capacity of 100 to 150 kilowatt each in the next five years. The company has also received a grant of Rs 24 lakh from automotive giant Mahindra & Mahindra. Company is already busy setting up a 120 kilowatt power plant in Chachret, a small village in Pithoragarh, home to 108 families. The power generated will be enough to light up 10 other villages, apart from Chachret, assuming each family consumes 100 watts of power, mainly for lighting and watching television. The plant will also generate enough cooking fuel for all the families in Chachret for the whole year. The company has signed an agreement to sell 750,000 units of electricity every year from the Chachret plant to Uttarakhand Power Corporation Ltd. The state utility benefits too, as the agreement will help it meet its target of procuring 10 per cent of its electricity from renewable energy sources.

The Uttarakhand Cabinet approved a policy for harnessing forest pine needles an alternative source of energy for generating power and it also approved the allocation of a piece of land. The Department of Power and Department of Forest will be the nodal agencies for the implementation of the policy. Pine needles are spread in an area of around 4 lakh hectare, which is around 16.36 per cent of the forest land. As per Uttarakhand government spokesperson and Minister for Urban Development, upon the implementation of the policy, we would be able to produce around 100 mega watt of electricity per year and also set up units for producing Pine Needle Briquettes (PNB) and bio fuel oil. The government intended to steadily increase the production of pine needle biomass beginning with 1 mega watt in 2019 and scaling it to 100 mega watt in the coming years. Further, the policy proposes to fix a base price (maximum) of Rs 5.36 paise for buying electricity generated through the pine needle biomass from individuals. The individuals setting up units through self help groups, registered firms, etc, would also be eligible for a subsidy as mandated in the state’s MSME policy.

Other benefits from the plant

Generating electricity from renewable sources also aligns well with local government policy and contributes to reduction in carbon emissions on a global scale. Apart from electricity generation, the high energy content residue of biomass gasification process is briquetted into cooking charcoal using a locally available binder. The availability of charcoal at door step has reduced the fuel gathering time of the villagers by 70% and provides a smoke - free environment to the villagers. 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, there by generating income for local people and saving the forests from being cut down. Company has also developed an efficient, inexpensive charcoal cook stove made entirely from locally available materials. Local people are trained to manufacture and repair the stoves, thus generating more livelihoods.

Major challenges faced

Addressing both collection and transportation challenges is key to the implementation of projects. Collection of pine needles involves carrying heavy loads over distances usually over steep slopes. Secondly, the moisture content of the pine needles causes lower efficiency and high maintenance for the gasification system. Company team is working towards better collection transportation and application of pine needles so that the resource can be best used for power generation.