BIOGAS WHATT!!!

With rising cost of living and global warming we need a source of alternate fuel sources. Biogas offers itself one such eco-friendly and cost-effective source of fuel, especially for the rural masses.

Limbala is one such village which came to limelight for being an early adopter of biogas. It is situated in the Saurashtra region of Gujarat. More than 300 families call this village their home. Most families in this village engage in agriculture or practices related to it for their livelihoods. Akin to most of the region, cotton is the most important crop of the village.

With average rainfall of just around 500 MM and total number of rainy days few and far between, many find it difficult to take a second crop during Rabi. For those who do, sorghum and wheat are the preferred crops for the winter season.

Most villagers also own livestock like cattle and buffalo to meet their families’ daily dairy consumption. Extensive cropping and grazing by the livestock, lack of any major water bodies and an extremely hot and dry climate has resulted in very low vegetation cover.

The high dependency on fuelwood, coupled with the low vegetation cover has at times forced the people of Limbala to venture into other villages in search of wood. This has occasionally led to heated exchange of words and other unpleasant situations in the village.

THE POOP PROJECT

Some of the farmers planned a visit to NDDB to understand the nitty gritty of setting and operating a biogas unit.

Note: A biogas unit a has three main components. A pit for storing the dung and water, a balloon for holding the gas and a pipe for carrying the gas from the unit to the stove.

Women headed households with small and marginal landholding became early adopters of biogas as they were the most affected by rising prices. A cap of at least 3 cattle/ buffalo was decided for someone who wanted to setup a biogas unit as around 45 KGS of dung is required per day to run a biogas unit of 2m3.

Access to direct sunlight and proximity to house and crop field were major criteria for deciding the plots for installing the biogas units. Once the finalisation of the plots was completed, the process of establishing the units began.

The owners of the biogas units contribute labour needed to set up the units. It is seen that the earth is particularly hard and rocky in the village which makes digging of pit for setting the unit a challenging task. So, the villagers hired earthmovers to do dig the pits. Afterwards, a specialist came to set up the balloons that will hold the gas. With the pits and balloons in place, water tankers were called with contribution from the community to pump water into the units.

Cow dung and urine were added and the mixture was left to decompose for a few days inside the unit. At the end of 4 to 5 days the balloons had completely inflated with methane which was released due to the anaerobic digestion of the dung by bacteria. This gas was released for the first time as it might have non-flammable air with it which might have been present when the balloon was first set up. The process of adding water, dung and urine is repeated and left for a few days. At the end of this second cycle the gas is finally ready to be used for cooking.

THE GOOD, THE GREAT AND THE BEAUTIFUL

20 of these units were established in 2021 and 2022 in Limbala to varying degrees of success. Most households that have taken the biogas connection use it on a regular basis. Some households mentioned that they have stopped refilling the LPG cylinders altogether and have given them to their relatives.

Each biogas unit produces nearly 100 L of slurry as a biproduct. This slurry is used as a direct bio fertiliser and for enriching farm manure depending on need of the farmers. The slurry acts as a pest repellent as well due to its strong smell which the insects find unpleasant. 5 of the 20 beneficiaries have used the slurry in different crops as a bio fertiliser and have reported good results.

The use of slurry in the farmland improved the quality of the soil, making it porous and softer after repeated usage. This also saved the farmers from effort of deep ploughing the land with is a labour-intensive task

Table 1- Inputs and outputs of a biogas unit

Some beneficiaries saved up to Rs. 5000/- in a year in LPG and fertiliser expenses.

These people now spend the saved income on other activities. Some women have also mentioned how they don’t have to go through the drudgery of fuelwood collection in scorching heat of Sayla as often as they did before.

The dependency on fuelwood has dropped amongst the households using biogas. Though the use of fuelwood has not completely stopped users mentioned a significant drop in the number of rounds for fuelwood collection. This saves the women of the village from a major hardship as this is predominantly a work that is done by females of the house.

The reduction in fuelwood use at house has also resulted in other positive impacts which were earlier not thought of. Now there is almost no smoke and carbon residue discharge from the cooking process saving the women from both inhaling the smoke and cleaning the walls and floors of the black discharge.

Though originally planned as greener fuel source, it has also improved the standard of living of the women in the villages along with fulfilling its intended objective.

THE STORY CONTINUES

After the relatively successful completion of the pilot more units are also being planned in Limbala. This time the plan is to mobilise the community to prepare slurry pits for better management of the slurry.

In the long run bio input-based enterprises can be setup in the village if the slurry management initiative goes as intended. This will help generate employment in the village along with promoting an arguably healthier, cheaper and eco-friendlier means of both fuel and soil enrichment.