Sustainable technologies for city infrastructure
Waste-to-energy plants, RWH, and solar power can obviate the need for dependence on municipal services for waste collection, water supply boards and centralised power grids. By M.A. Siraj
Curtailing our dependence on fossil fuels for energy, conserving water and bringing down emission of hazardous gases into the atmosphere, hold the key to sustainable living in our cities. Although much awareness has been aroused, the only way it could be achieved is to take the technology to the doorsteps of the people. Sizeable sections of people are keen to join the sustainability bandwagon, but capital cost and hassles of installation of biogas plants — whether big or small — often dissuade them from going for renewable technologies.
The Centre for Renewable Energy and Sustainable Technologies at the National Institute of Engineering (NIE-CREST) in Mysuru has been making a sustained effort to take these technologies to individuals as well as institutions in their simplest form. Last month the CREST inaugurated its 50-kg biogas plant on the NIE campus that takes kitchen waste as the basic feed.
NIE is the oldest engineering institute under a private management with government aid. It hosts nearly 4,000 inmates within the 10-acre campus at any point of time. Several messes and canteens generate around 1.5 tonnes of waste every day. Under the new rules framed by the Ministry of Environment, bulk generators such as institutions, hotels, hostels and hospitals, are supposed to hand over their wet waste to the municipal authorities in plastic bags and pay the transport charges to carry them to the dumping yard.
Waste-to-energy
The biogas plant with 50-kg daily intake of kitchen waste as feed is the fifth and the largest in a series of plants the CREST has come up within the campus in recent years. Earlier it had established four plants with capacity to take 10, 5, 15 and 2 kg of waste (in that order) a day in various sections of the campus. According to S. Shamsundar, who heads the CREST, the new plant obviates the need to send out 18 tonnes of waste annually to the landfill and produces 432 kg of biogas which is used in cooking stoves at the canteen.
Following extraction of gas, 90% of the waste gets degraded into manure which is sold to farms and orchards. Waste is thus used as a resource for extracting gas, thereby saving cost of transporting the same to landfills. A portion of the gas is also used for powering engines in the Mechanical Department of the NIE.
Many locations
The NIE has installed biogas plants at the Administrative Training Institute, Mysuru; Hindustan Unilever factory at Hebbal Industrial estate in outskirts of the city; Oxygen Acres farm on the road to T. Narsipur; New ISRO Layout at Yelahanka in Bengaluru; Parmathi School, Mysuru, and Bapuji Institute of Davangere.
Its largest plant so far was installed in Mysore zoo which takes 1,500 kg of waste a day. It has developed and installed smaller plants for nearly 150 homes in Bengaluru and Mysuru which together can fill 1,500 cylinders of 12 kg each. Recently, Mr. Shamsundar visited Vanuatu islands in the South Pacific Ocean where NIE will be taking up the installation of a biogas plant at the largest residential school.
Ideal climate
Says Mr. Shamsundar, once people realise the worth of the waste, they begin to respect it for the value it yields and may perhaps compete to claim its ownership.
According to him, an individual household generating 5 kg of waste a day could have a biogas plant for ₹ 26,000 based on a plastic drum. However, if one opts for a steel drum, the cost would go up to ₹ 35,000. He says the biogas plants operate on the principle of anaerobic digestion of the waste, producing methane which is a gaseous fuel. “The climate in countries like India where temperature does not dip beyond 8 degree Celsius, is ideal for the process. Besides, the slurry that comes out of these plants serves an excellent organic manure. It is a sustainable concept as it leaves no carbon footprints behind,” he remarks.
RWH at Mysuru palace
The NIE has also been promoting rainwater harvesting in Mysuru. The centre supplied the technology and the wherewithal to the Amba Vilas Palace to harvest the entire water pouring down on its 70-acre premises during the monsoons. The centre constructed 10 storage tanks within the Palace compound in 2011 which cumulatively collect 10 million litres of rainwater annually. At any point of time during the year, the Palace has 10 lakh litres of clean water under its sumps.
The Administrative Training Institute too availed of the CREST consultancy in 2010 to pool 31 lakh litres of rainwater annually from the 4,900 sq. metre harvestable area.
The Institute authorities say most of the water is allowed to percolate to recharge groundwater aquifers. However three underground tanks can together store 700,000 litres of clean water at any point of team. The KSIC followed suit and built three sumps to collect a total of 7.20 lakh litres from a 9,000 sq. metre area on ther premises. Similar installations are under progress at MUDA and CPWD premises.
The CREST is currently guiding the installation of solar panels all over the roofed space of the NIE. The panels being mounted on the top will be able to capture enough sunrays to be converted into 30,000 units of power a month, which will cut down its dependence on Chescom grid by 42%.
‘Aranyaka’
The CREST sponsors 50 composters for government schools annually under the Waste Management Programme. Each batch of students at the Mechanical Engineering Department produces 50 kg of biofuel through a variety of seeds under the guidance of the CREST.
The centre has recently set up an eco-friendly anti-poaching unit named ‘Aranyaka’ in Bandipur forest using mud-blocks and solar power.
Source: thehindu
