Sep 30, 2008

World - Amsterdam uses garbage to light up the city (G.Read)

Anil Sasi
Recently in Amsterdam The success of a waste-to-energy project in far-away Amsterdam could solve the most pressing problem of Indian cities and towns, which are grappling both with growing garbage pile-ups and power shortages.
Using solid garbage as fuel, the Amsterdam’s Waste and Energy Company, or AEB, generates 1 million MWh of electricity yearly, which is used to run the city’s trams and the metro network, its street lighting, and designated public buildings.
Besides, heat generated by waste incineration at the plant, estimated at around 300 giga joules a year, is piped directly to over 15,000 homes.
The utility — owned by the City of Amsterdam — handles close to 1.6 million tonnes of industrial and domestic waste annually. Besides power and heat, the AEB has been turning virtually all of the city’s waste into recycled-grade metal, gypsum, limestone and salts using processes that utilise some 30 in-house innovations.
While power from the plant, routed through local power utilities for distribution, costs higher than generation at a regular coal-fired power plant, a subsidy element plugs the difference. The AEB, as a utility, however, has been clocking profits on account of its comprehensive waste handling skills.
“We’re able to take 99 per cent of the city’s waste and incinerate it with virtually zero discharge,” Dr N.R. Pattavina of AEB told a group of visiting journalists invited by the City of Amsterdam.
How does it work? Hundreds of rubbish trucks converge on the AEB site, bringing in garbage collected from industry and households. After weighing, the garbage goes to the Waste-to-Energy Plant.
Here it’s discharged into a huge bunker, and then incinerated over grates round-the-clock. The heat released by the combustion converts the water in the connected boiler walls into steam, which drives turbines that generate electricity. Much of the resultant heat is piped directly to local homes and businesses.
The majority of the substances that do not burn are transformed into so-called bottom ash that find use in processes such as road construction, besides metal scrap recovery.
In the Netherlands, there are 11 waste-to-energy plants in operation currently; AEB sets the efficiency benchmark as it uses an extra turbine to recycle the spent steam.
With India’s urban population slated to rise from the current 330 million to about 600 million by 2030, and per capita income continuing to rise, the challenge is to manage municipal solid waste (MSW) in an environmentally and economically sustainable manner.
According to a recent Assocham study, about 40,000 million tonnes of solid waste and 5000 million cubic metres of liquid waste is generated every year in the urban areas which can be suitably recycled for power generation. About 1,500 MW of power could be generated from urban and municipal wastes and an additional 1,000 MW from industrial waste in the country by 2010, the study estimated.

No comments: