Should we continue using nuclear, coal, hydel, or turn to some cleaner source such as solar, wind, and bio-gas: much has been debated about this issue, with many saying the best option would be turning to renewable energy source. Chennai seems to have already caught the alternative energy fever, with many putting up solar panels in their houses and doing every bit to conserve energy.
The students of Shasun Jain College for Women, T. Nagar, and memebrs of Students in Free Enterprise have gone a step further and installed a bio-gas plant in the college campus. Inspired by the work of Exnora Pammal Green project, the students launched this pilot project to supply gas to the college canteen.
The vegetable waste generated from the college canteen, bio-degradable waste from the nearby Ranganathan Street and cow dung is used to feed the anaerobic digester. Akshaya, one of the seven students who worked on the project, says, “It takes one week for the plant to produce gas.”
The plant produced two cubic metre of bio-gas, which is equal to 0.90 kg of LPG.
The gas can only be used for 45 minutes a day for light cooking such as heating water and making tea and coffee.
“First, cow dung is placed in the digester which produces bacteria. Following this, 25 kg of vegetable waste is grinded and converted into semi-solid waste and fed into the digester along with 25 litres of water. After a week, bio-gas is produced. To get continuous supply of gas, three to four kg of waste should be added everyday,” she adds.
The plant’s outlet is connected to a stove, specially designed for using bio-gas. Sludge, which is a by-product of bio-gas, can be used as manure for plants. Apart from being economically cheap and an environmentally clean technology, no smell emanates from the digester and cooking time is also reduced considerably.
Bio-gas can also be used for illuminating the street lights by installing a larger plant. However, it cannot be stored for long as it is highly combustible and must be used regularly.
“One drawback of the bio-gas plant is the initial cost of installation. An anaerobic digester costs more than Rs. 25,000, which is not affordable for all. This problem can be addressed by making use of old sintex tanks. We are still researching on this,” says Akshaya.
Next, the students want to install a bigger plant in their college and depending on its success take the project to rural areas as part of their community welfare initiative.