Waste-to-Energy: Renewable Energy Instead of Greenhouse Gas Emissions

Global generation of post-recycling municipal solid wastes (MSW) in populated centers amounts to about 1.2 billion tons. Most of this is landfilled, thereby adding to the atmosphere emissions estimated at about 45 million tons of methane, the second most important greenhouse gas. Projected population growth and economic development are expected to double the rate of MSW landfilled by the year 2030. The only proven alternative to the landfilling of post-recycling MSW is controlled combustion or gasification to recover energy and metals. Worldwide, there are over 600 thermal treatment plants, most of them in E.U., Japan, the U.S., and more recently in China. The most efficient waste-to-energy (WTE) facilities recover as much as 1000 kWh of electricity and district heating per ton of MSW processed. However, in total less than 200 million tons of MSW are subjected to thermal treatment. At the current rate of growth of the global WTE industry, estimated at only four million tons of new capacity per year, methane emissions from landfills will continue to be a significant source of greenhouse gases (GHG) as far out as 2030. Despite the several advantages of WTE over landfilling (energy and metal recovery, GHG reduction, and, most importantly from the viewpoint of sustainable development, land conservation), its wider application has been impeded by a) well meaning environmental groups that are not aware that modern WTE facilities bear no resemblance to the polluting incinerators of the past, and b) short term economics that do not take into account the environmental and land conservation advantages of WTE. Nevertheless, as major urban centers, like New York City, have run out of landfill space, the combined costs of long distance transport and landfilling municipal solid wastes have increased to the point that waste-to-energy is much preferable to landfilling, both economically and environmentally