A growing number of Indians are enjoying a new found ability to consume a vast number of goods and services that were previously either unavailable or unaffordable. From small electronic items, such as cell phones, to large consumer goods like refrigerators and cars, Indian consumption has been steadily increasing and shows no signs of abating anytime soon. Inevitably this has led to a rapid growth in the quantity and variety of MSW. In most cities and towns in India, MSW is disposed off in an unregulated and unscientific manner in low-lying, open dumps on the outskirts of cities. Most dump lack systems for leachate collection, landfill gas collection or monitoring, nor do they use inert materials to cover the waste. This result in ground and surface water contamination from runoff and lack of covering, air pollution caused by fires, toxic gases, and odour, and public health problems due to mosquitoes and scavenging animals.
In its 2009-10 Annual Report the Ministry of New and Renewable Energy (MNRE) estimated that approximately 55 million tonnes of MSW are generated in urban areas of India annually. It is estimated that the amount of waste generated in India will increase at a rate of approximately 1-1.33% annually.
The Ministry of Environment and Forests (MoEF) promulgated the Municipal Solid Wastes (Management and Handling) Rules in 2000 requiring municipalities across India adopt sustainable and environmentally sound ways of processing MSW, including incineration. In this regard, Waste to Energy (WtoE) provides a solution towards complying with government regulations, and achieving integrated solid waste management. The Indian Government considers WtE to be a renewable technology, and the MNRE has developed the National Master Plan for Development of WtE in India.
The MNRE lists a number of technologies for energy recovery from urban and industrial wastes that “not only reduce the quantity but also improve the quality of waste to meet the required pollution control standards, besides generating a substantial quantity of energy”. The MNRE estimates that the potential to generate power from MSW will more than double in the next ten years, while the potential from industrial waste is likely to increase by more than 50%.
While the Indian Government’s own figures would suggest that the cost of WtE is somewhat higher than other renewable sources, it should be kept in mind that WtE facilities serve a dual role of waste disposal and energy production. Although the cost per MW of capacity may be greater than other renewable sources, the benefits of waste management, energy and metals recovery, and reduction of GHG emissions need to be considered.
Considering WtE for Mumbai City
Mumbai has been facing a solid waste management crisis for years. The infrastructure has been unable to keep pace with economic development and population growth. In order to move towards a sustainable future and achieve its goal of becoming a world-class city, Mumbai needs to adopt an integrated solid waste management approach.
The agency responsible for solid waste management in Mumbai is the Solid Waste Management Department (SWMD) of the Municipal Corporation of Greater Mumbai (MCGM) and its private contractors.
The municipal corporation spends roughly `1160 per tonne ($25/tonne) on collection, transport, and disposal of MSW. Collection and transport together constitute roughly 80% of the cost. In India, the average municipal expenditure on solid waste management is `500 to `1500 per tonne ($10 to $32 per tonne).
Suitability of WtE in Mumbai
The MSW collected in Mumbai consists of wet organics (primarily food waste), dry organics (straw and wood, etc.), inert materials (sand and soil), and recyclables (plastics, metal, glass and paper). Based on the composition of MSW, processing the waste in a WtE facility would reduce its volume by 96.74%, thus freeing up land that would otherwise have been used for landfills.
The chemical characteristics of MSW in Mumbai have been measured by two different studies, one by the Central Pollution Control Board (CPCB) and the National Environmental Engineering Research Institute (NEERI) in 2005-06, and the other by MCGM around the same time.
The reported moisture content and heating value differs significantly between the two studies, however, the CPCB-NEERI study found that the heating value of MSW in Mumbai is sufficient for a WtE plant to operate without additional fuel. From an environmental standpoint, a WtE facility would be beneficial because it would prevent the formation of leachate that contaminates groundwater, reduce emissions of toxic pollutants from the burning of garbage, and prevent the production of two potent greenhouse gases, carbon dioxide and methane.
Additionally, with space in urban areas at a premium WtE provides an effective way to reduce the volume of waste by approximately 90% and thereby lower the space needed for landfills.
More research is needed to quantify various aspects of the solid waste management sector. A number of key statistics, such as the value of recyclables, the amount of environmental pollution from waste sources, and the quantity of industrial waste generated, need to be computed to gain a better understanding of this sector. In terms of research related to WtE, detailed analysis of costs and available funding is needed. In addition, investigating the suitability and quantifying the costs and benefits of combined heat and power for Mumbai would be useful. Independent researchers or consultants should carry out such research in order to prevent any biases that may otherwise occur.
Outreach to both environmental groups as well as the public at large is important in order to demonstrate the benefits of WtE technology to the community, city, and local government. This can be achieved by educating the public through campaigns, workshops, town hall meetings, university lectures, and so on. Creating an open dialogue with environmental groups is an essential first step to sharing information and collaborating to create better environmental conditions.Perinaz Bhada-Tata Source: Waste Management World