This article was posted in the kuensel issue of May 2, 2011.
Waste generation is a growing issue, which had been highlighted in the past by Thimphu City Corporation (TCC). It is a consequence of urbanization and economic development which we cannot avoid. We should have tools in our hand to handle it. The Landfill in Memelakha which was built in 1994 is overused by now. It has been accommodating the waste generated by the residents of Thimphu for the last 16 years – it has done its duty. The waste generation of 22 MT/day in 2004 increased to 50 MT/day in 2010 giving a compound annual growth rate (CAGR) of 14.66%.
With the concern of rising Municipal Solid Waste (MSW), TCC contemplates proposals such as: getting second landfill site and privatizing waste disposal system. The second landfill will be filled up at a faster rate which could be taken as a medium term measure. Privatizing waste disposal system may just take care of the administrative burden hitherto been faced by the TCC. Something additional to these measures may be required. Something that can turn it into resource. The UNEP (2001) states that MSW won’t be a problem if we view it as a resource and manage properly. So probably we could also look at our MSW also as a resource and increase our capacity in recycling it or converting it to energy. By recycling we can reduce resource depletion and by direct combustion in incinerators, we can generate heat and electricity. There is a private agent which segregates the MSW and sends them to India for recycling. There is also a small scale waste decomposing plant in Serbithang. They are yet to show an impact on the waste reduction in the landfill site. Either these two activities have to leap one step further or else we promote ‘waste to energy’ concept. MSW can be problematic to discard because of its large volume. MSW power plants are in operation in many countries and Bhutan cannot be an exception. The Renewable Energy policy (draft version) allows project developers to venture into the business of waste to energy generation. The only thing we require is a comprehensive feed-in tariff policy such that construction, operation and maintenance of such Renewable energy technology (RET) become commercially viable to compete with the cheap hydroelectricity in Bhutan. Installation of MSW plants could lead to reduction in the piling up of waste in the land fill site and also feed in electricity to the grid.
Irrespective of winter or summer season, waste generation will always be there, therefore it can supplement the low hydro generation during winter season, though to a small quantum. The Bhutan Energy Data Directory (2007) estimates that MSW quantity of 222,244 kg/day can produce 61,406 kWh/day. Based on this estimation, the daily MSW generation of 50 metric tons in Thimphu will have the potential to produce 13,815 kWh/day. So considering the annual electricity consumption level in Thimphu in 2010, which is around 5600kWh per customer, the MSW plant will have the capacity to suffice the electricity need of around 890 customers. Unlike the seasonal variation of water in-flow, waste generation is throughout the year which gives higher plant capacity factor.
Converting waste to energy will play important role in reducing the social issue of MSW disposals arising from rapid urbanization. There will be emissions of pollutants from MSW plant which may go against our carbon neutrality dogma. However deploying MSW plant will reduce piling of waste in the land fill which could outweigh other environmental issue since piling of waste itself is an environmental issue and as a matter of fact there is always emission of methane gas from the land fill site. The emission from the MSW plant could be very insignificant given our vast carbon sequestration capacity provided by our forest cover. We reduce our MSW stockpiles and generate energy (heat and power) from waste, what else is there to look for!!