Waste-to-Energy

Adapted from A-way with Waste: A Waste Management Curriculum for Schools

2nd ed., Dept of Ecology, State of Washington

 

Back to Trash Goes to School

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GRADE LEVELS: 9-12

 

SUBJECT AREAS: social studies, civics, government

 

CONCEPT: Solid waste can be used to create energy.

 

OBJECTIVE: To learn what resource recovery plants are and basically how they operate. Students will consider the positive and negative aspects of resource recovery as a solid waste management option.

 

MATERIALS:

- telephone
- local incinerator
- handout: Solid Waste Options

 

KEYWORDS: bottom ash, waste-to-energy, refuse-derived fuel

 

BACKGROUND: We must look at all our options for safe and proper disposal. One of these options is the use of resource recovery facilities (also known as waste-to-energy plants).

Resource recovery facilities are an expensive, highly technological method of dealing with large volumes of solid waste. The basic operating principle of resource recovery plants is to burn refuse. Recyclables may be separated out by mechanical means before burning ("front-end processing") or after burning, or they may not be separated out at all. In any case, 20 to 30 percent of the original refuse is noncombustible and nonrecyclable and must be disposed of in a landfill.

 

Intense heat from burning is used to create steam, which in turn may be used to generate electricity. Solid waste managers hope that a continuing rise in the cost of electricity will help pay off the cost of energy recovery plant construction. Given the enormous volumes of solid waste produced in urban areas, some solid waste managers have come to see energy recovery facilities as necessary components of solid waste management systems, along with landfills and recycling.

 

Critics of energy recovery plants, however, raise objections. Some of these are the high cost of construction, the air pollution caused by refuse burning, and the ash which contains heavy metals and must be disposed of in landfills. Critics also point out that energy recovery plants require a steady flow of garbage. Maintaining that flow, critics say, will discourage recycling and will allow people to avoid their individual responsibility to generate less waste. This objection can be answered by taking recycling into account when sizing the incinerator.

 

PROCEDURE:

Consider the following solid waste management options:

- prevention
- reduction (selective buying to reduce waste)
- recycling
- composting
- energy recovery facilities
- landfills

Research and discuss each of these options (these are listed in order of national priority). Discuss the pros and cons of each, and list on the following table.

Remember that each community is unique and needs its own waste management plan. There are no master blueprints for waste disposal.

 

After researching and discussing the options, put together a plan for your community, taking into consideration the following:

- pounds of garbage produced

- community water supply
- population
- rural vs. urban land available
- air quality
- the environmental effects of the disposal method
- roads and bridges (adequacy for transport of wastes)
- presence of materials that don't burn or are dangerous in landfills or incinerators.

 

 

Ask:

- Which combination of options would best serve your community in the long term?

- Is any one of these options adequate on its own to handle your community's solid waste?

- If you were the city official with responsibility for dealing with solid waste, which options would you choose?

- Who in your local government makes decisions about the management of solid waste?

After this exposure, you may want to get involved in your community's planning process.

 

FOLLOW-UP:

Organize a debate around the following proposition: Our city/county should build a waste-to-energy plant to incinerate our garbage. Call solid waste managers, recyclers, leaders of environmental groups, and representatives of a burn plant construction company for various points of view on this subject.

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