Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments
3.0 Renewable Energy Technology
Options
3.4.1 Municipal Solid Waste Mass Burn
There are currently 65 WTE plants in the United States using mass burn
technology to generate electricity. These plants burn MSW in “as-discarded” form, with
minimal or no pre-processing of the waste. Waste to energy facilities employing mass
burning of MSW were seen in the 1980s as an environmentally sound and cost effective
method of handling the problem of diminishing available landfill space in the United
States. However, as concerns about environmental pollutants (particularly dioxin) from
the plants have risen, opposition to new projects has become increasingly effective. In
addition, costs for MSW facilities have often exceeded initial estimates, and communities
are left paying for the plants for years. To its credit, the industry has drastically
decreased dioxin emissions over the past decade. Nevertheless, since 1996 only one new
MSW facility has come online in the United States. That project retrofitted an existing
incinerator to generate steam for a turbine generator. The plant is located in Michigan
and is shown in Figure 3-7.
Figure 3-7. Central Wayne Waste to Energy Plant.
Converting refuse or MSW to energy can be accomplished by a variety of
technologies. The degree of refuse processing determines the method used to convert
municipal solid waste to energy. Unprocessed refuse is typically combusted in a water
wall furnace (mass burning). After only limited processing to remove non-combustible
and oversized items, the MSW is fed on to a reciprocating grate in the boiler. The
combustion generates steam in the walls of the furnace, which is converted to electrical
21 March 2005 3-33 Black & Veatch