The Hindu             22.11.2013

Students tap energy from scrap

What happens to tonnes of vegetable oil that are reused in Puducherry’s many hotels, restaurants and roadside eateries? What about the old gears and metal rusting away in scrap shops? Or shavings and bones that are piled up when the fish market closes for the day?

Little thought goes into what happens to everyday residue and leftovers. But students from Puducherry schools clearly have their eyes and ears open. The selected projects that have made it from the Union Territory to the National Children’s Science Congress (NCSC) in Bhopal this year have all capitalised on discarded material, turning waste into energy and resource.

The NCSC is an annual affair that cultivates scientific temperament in school children by prompting them to apply scientific concepts to problems and issues around them over a period of three months. This year a total of 178 projects were presented from Karaikal, Mahe, Yanam and Puducherry at the district level.

From a total of 29 projects selected for State level, six have made it to the national finals, of which the top two will also get to present at the Indian Science Congress in Jammu and Kashmir.

Mira Arabinth and his team of Class XI boys from Petit Seminaire, believe every tiny amount of energy counts. The boys have come up with a proposal to convert mechanical energy into electrical energy, from the pressure exerted by vehicles when crossing the speed breakers. “This idea works better at toll gates, where there are eight lanes and multiple speed breakers, with one vehicle crossing at one time,” says Arabinth.

A contraption designed on the rack and pinion model captures, converts and stores the energy. The boys fashioned it from gear in scrap shops. “The challenge for us now is to convert this variable current into steady flow of electricity before the national-level presentation,” says Arabinth.

Around 15 watts of energy can be generated, depending on the mass of the vehicle. “Even if it burns a lamp, it is energy and can help tide power crisis,” says S. Midhune.

The youngest members among the selected teams, who finished second, are girls of Class VII from St. Patrick Matriculation School, who have tried extracting biodiesel from used vegetable oil.

“We have read biodiesel can be extracted using castor oil. We thought why not go for a more economical option by using residue vegetable oil,” says V. Nivetha.

“Some big hotels told us they sell the reused oil to petty shops for frying purposes,” says S. Subitshaa, adding that an average restaurant used up at least 40 litres per month.

The students confirmed biodiesel by testing it in a lab and used it successfully as a stain remover, says D. Beulah, guide teacher. “Now we are trying to use it in a second-hand vehicle”.

In putting scientific concepts into practice, students came across new experiences. For girls from St. Joseph School of Cluny, the project was the first time they used wood stoves, says Mahalakshmi. The team compared four variations like charcoal, pellets, firewood, sawdust of both the casuarina and blueberry wood to conclude on the most efficient source of energy. “There are a lot of villages where wood stoves are used, causing breathing and other problems,” says O. Anjana, her teammate. “Our study shows blueberry pellets are a greener, cheaper and more efficient alternative,” says Francita.

N. Narendiran and team, also from Petit Seminaire, have tried to compare the most productive resource for biogas production — prawn and fish waste or vegetable waste. “We visited the market and found that much of the waste is left as litter on road corners. By producing biogas from them, we can channel them for cooking meals in governemt hostels for mid-day meals in schools,” says Narendiran. While there was marginal difference in burning time, the team found prawn and fish waste produces gas in three days, while it takes double the time for vegetable waste.

Disadvantage government schools

The number of participating schools this year has gone down. Except for two schools in Mahe, who make up the selected six, only private institutions from Puducherry have made it to the national level. Government, rural and Tamil-medium schools figure nowhere in the top. There is need to level the playing field, feel members of the Puducherry Science Forum, the local organising body.

The question is who will spend for the projects in government schools, says K. Vijayamurthy, Liasion Officer, Puducherry Science Forum. The Education Department must motivate teachers, who in turn can motivate students, he adds.