The nation's municipal solid waste
(MSW) - the garbage and refuse from households, commercial buildings, and
institutions, (e.g., schools and hospitals) - is a renewable source of energy
that could provide low-carbon energy, potentially replacing fossil fuels. In
2008, Americans generated about
million tons of trash and recycled and composted 83 million tons of this
material, equivalent to a 33.2 percent recycling rate. On average, we recycled
and composted 1.5 pounds of our individual waste generation of 4.5 pounds per
person per day.
Across the country, many communities,
businesses, and individuals have found creative ways to reduce and better
manage MSW through a coordinated mix of practices that includes source
reduction, recycling (including composting), and disposal. Source reduction
involves altering the design, manufacture, or use of products and materials
to reduce the amount and toxicity of what gets thrown away. Recycling
diverts items, such as paper, glass, plastic, and metals, from the waste
stream. These materials are sorted, collected, and processed and then
manufactured, sold, and bought as new products. Composting decomposes
organic waste, such as food scraps and yard trimmings, with microorganisms
(mainly bacteria and fungi), producing a humus-like substance.
According to the Integrated Waste Services Association (IWSA), the 89
waste-to-energy plants nationwide dispose of more than 90,000 tons of trash
each day while generating enough clean energy to supply electricity to about
2.3 million homes nationwide.
In addition, the billions of tons of
wastes currently buried in municipal landfills is biologically decaying and
releasing large quantities of the greenhouse gas methane. The Argonne
National Laboratory has estimated that at least some of this methane could
be practicably recovered and converted into electricity. The U.S. EPA's
Landfill Methane Outreach Program (LMOP) is an assistance and
partnership program that promotes the use of landfill gas as a renewable,
green energy source.
To reduce waste volume, local governments
or private operators can implement a controlled burning process called
combustion or incineration. In addition to minimizing volume, combustors,
when properly equipped, can convert water into steam to fuel heating systems
or generate electricity. Burning MSW can generate energy while reducing the
amount of waste by up to 90 percent in volume and 75 percent in weight.
MSW may be also processed to yield a
higher Btu, lower ash, refuse-derived fuel (RDF) which can be used in
variety of boilers.
For other options related to waste fuels,
see the sections of the PPRG describing
Coal Mine Methane Recovery,
Landfill Methane Energy Recovery, and
Animal Waste Methane Energy
on "Add PPRG Content" above to
comments to the PPRG.