Waste-to-Energy: A Better Solution for America’s Energy Needs

by Diane, M.P.H, M.S.

“Waste is better utilised through incineration than through landfills, but recy­cling is an even better option. Of course, the best option is prevention of waste production altogether, which often requires direct reuse. The less waste, the better – it’s as simple as that.”

Copenhagen Waste Solution, City of Copenhagen (2008)

Waste-to-Energy Plant by BIG

Danish architects Bjarke Ingels Group have won a competition to design a power plant for Copenhagen with their design that will blow smoke rings and double up as a ski slope. The Waste-to-Energy Plant will replace the neighbouring Amagerforbraending plant and will function as a treatment facility that transforms waste into energy.

Municipal solid waste (MSW), otherwise known as garbage, is a ubiquitous byproduct of industrialized societies. In the United States, sanitary landfills are used most often to dispose of MSW, but the limited availability of land in some places can make it difficult to find suitable locations for new landfills. In some cases, leachate produced from landfills can contaminate ground water. Landfills are also a source of substantial greenhouse gas (GHG) emissions. The Environmental Protection Agency (EPA) estimates that 22.3% of U.S. methane emissions in 2008 came from landfills (7). Furthermore, landfills contain much unused energy in the form of MSW. Even when landfill-gas-to-energy (LFGTE) systems are used, they do not recover all of the methane produced by decomposition of MSW (1).

One alternative to LFGTE is the combustion of MSW to generate electricity or heat in a process known as waste-to-energy (WTE). WtE refers to any waste treatment that creates energy in the form of electricity or heat from a waste source that would have been disposed of in a landfill. WtE is a renewable energy because its fuel source, garbage, is sustainable and not depleted. According to the U.S. Environmental Protection Agency, WtE is a clean, reliable, renewable source of energy. Today, the U.S. burns 14 % of its solid waste by means of 89 WtE plants in 27 states.

Garbage is a wonderful mixture of energy-rich fuels:

The average American throws away about 5 pounds of trash every day. More and more waste is produced each year in the United States, and populated areas are running out of space for new landfills. From 100 pounds of typical garbage, 80 or more pounds can be burned as fuel to generate electricity at a power plant. A ton of garbage generates about 525 kilowatt-hours (kWh) of electricity, enough to heat a typical office building for one day. Urban areas could benefit greatly from this form of energy, since the fuel source is readily available in large quantities, pollution and the need for landfills would decrease, and ultimately the dilemma of waste management would be reduced.

Waste-to-Energy (WtE)= Energy-from-Waste (EfW):

Residual waste that cannot be recycled in an economic or environmentally beneficial way offers a valuable local source of climate-friendly energy for the benefit of both people and the environment.

WtE is the process of creating or recovering energy in the form of electricity or heat from the incineration of this non-recyclable garbage. Combustible fuel in the form of methane, methanol, ethanol, or synthetic fuels can also be produced this way. Modern waste-to-energy plants actually outperform alternative forms of waste treatment such as landfills and ocean dumping (Yes-this still occurs!), in terms of their carbon footprint and other impacts on the environment.

Europe has greatly surpassed the United States in developing technology to convert residential and industrial trash into heat and electricity, without the release of harmful emissions or other environmental pollution. Modern plants use highly effective filters and scrubbers to capture chemicals such as hydrochloric acid, sulfur dioxide, nitrogen oxides, dioxins, furans and heavy metals, as well as, small particulates.

Already 400 such plants have been built and are operating in Austria, Belgium, Denmark, Germany, the Netherlands, Sweden, and Switzerland. These countries also have the highest rates of recycling in the world and burn only non-recyclable material in their energy-generating incinerators.

 

There are more than 600 modern WTE facilities, including 89 in the United States, operating worldwide without any significant pollution. They produce much-needed clean, renewable energy, replacing the need to extract and burn coal, oil, and natural gas.

 
One famous example of a waste-to-energy plant is “Spittelau,” in the centre of Vienna, Austria. The Spittelau plant provides the nearby hospital with heating and cooling and is one of several plants that provide such services for the city. The plant resembles a work of art and is so well known as a city landmark that it attracts tourists from around the world. 
 

What goes on at a Waste-to-Energy plant?

WtE plants are somewhat like coal-fired power plants. The difference is the fuel. WtE plants use garbage, not coal, to fire an industrial boiler. Similar steps are used to make electricity in a waste-to-energy plant as in a coal-fired power plant:

  1. The fuel is burned with high temperature combustion that completely destroys viruses, bacteria, rotting food, and other organic compounds found in household garbage that could potentially impact human health.
  2. The heat generated turns water into steam which can be used in a heating system or a factory.
  3. Typically the high-pressure steam turns the blades of a turbine generator to produce electricity.
  4. After any incombustible residue (ash) cools, magnets and other mechanical devices pull metals from the ash for recycling. This is an important step, since a WtE plant can recycle thousands of tons of metals from its ash.
  5. The really advanced technology in burning trash is the air quality (emission) control system. America’s waste-to-energy facilities today meet some of the strictest environmental standards in the world and employ the most advanced emissions control equipment available including scrubbers to control acid gas, fabric filters to control particulate, selective non-catalytic reduction (SNCR) to control nitrogen oxides, and carbon injection to control mercury and organic emissions.
  6. Another challenge is the disposal of the ash after combustion. Ash can contain high concentrations of various metals and harmful chemicals that were in the original waste. The ash is tested for harmful substances and can then be reused for many applications. Most of the ash is used to build roads and make cement.
  7. Finally a utility company sends the electricity that was generated along power lines to homes, schools, and businesses.

A waste-to-energy facility can generate a range of outputs:

  • Electricity
  • District heating
  • District cooling
  • Steam for industrial processes
  • Desalinated seawater

Vestforbrænding, courtesy of Vestforbrænding

In 2004, the amount of heat and power generated from waste in Copenhagen was enough for the needs of 70,000 households, producing 210,000 MWH of electical energy and 720,000 MWH of heat. All of this energy was obtained from the city’s three municipal waste incinerators: I/S Amagerforbrænding, I/S Vestforbrænding, and Rensningsanlæg Lynetten.

Modern waste-to-energy plants offer many benefits because they:

  1. Produce electricity with less environmental impact than almost any other source of electricity, including coal mining, oil drilling, hydraulic fracturing for natural gas, and nuclear power (7).
  2. Are cleaner than sanitary landfills in terms of overall environmental pollution when properly equipped with pollution control devices for flue gases (1).
  3. Offer a more efficient energy recovery system than LFGTE.
  4. Promote the concept of ‘zero waste,’ i.e., reduce, reuse, recycle.
  5. Do not require foreign oil or fossil fuels for their operation: Dependence on foreign oil is reduced. Oil prices fluctuate, and many of the remaining reserves are in Middle East countries which do not feel friendly towards westerners.
  6. Produce energy domestically: American homes and landfills provide plenty of trash each day, enough so that materials for this process would never have to be transported very far or run out. Many landfills are already overflowing with this alternative energy source.
  7. Promote stability in availability and pricing of electricity, since there are no wide fluctuations in the availability of trash.
  8. Can operate 24 hours a day, every day of the year, providing more than enough electricity to meet local community needs.
  9. Benefit the local community and economy: Since municipal waste-to-energy plants are built to provide for the local area, instead of being situated far away, they offer many advantages to a community. Jobs are created, taxes are paid, supplies are purchased at local businesses and stores, and energy is provided for a reasonable cost that does not pollute or harm the environment.
  10. Provide additional economic benefit in recovering up to 90% of ferrous materials from both waste-stream inflow and bottom-ash outflow: 77% of WtE facilities in the USA already have this capacity.
  11. Reduce the need for landfills and reduce environmental pollution: By using municipal WtE facilities space is preserved in landfills. Trash that is incinerated would otherwise take up space in a landfill and contribute to environmental degredation. Many landfills around the world have closed, since they have reached full capacity. The world is running out of places to dump the trash being created daily.
  12. There is an unlimited supply of municipal waste: With all the garbage generated globally each day, plus the refuse in many landfills, there is enough trash to generate all the electricity needed. Our oceans are also littered with waste, offering another source of energy.
  13. Significantly reduce greenhouse gas emissions: WtE plants release a minute fraction of the emissions produced by fossil fuel power plants. This means far fewer emissions to damage the ozone layer and contribute to global warming.
  14. Do not pose a risk to environmental or public health: There are no dangerous chemicals or toxins either used or released to poison wildlife and contaminate land and water in the area. Pollution and greenhouse gas emissions are far less than using coal or other resources.
  15. Promote recycling: Less waste occurs because of items being sorted and recycled. Note that for each item recycled there is about 20% more energy conserved than what is needed to manufacture the item. Recycling minimizes both the need for natural resources and environmental damage.
  16. Are strictly monitored: These power plants undergo very strict emissions testing. Every step of the process is monitored closely. In fact, these facilities must meet stricter operating standards than any other type of power plant, and if these are not met, the plant is immediately shut down.

Waste Management Method Comparison Between Sweden and the United States:

                                                                              United States                                                        Sweden

Recycling/composting:                                     34%                                                                       48%

Waste-to-energy:                                                  12%                                                                       49%

Landfill:                                                                    54%                                                                         3%

 

Some words of wisdom:
  • As Nickolas J. Themelis, Professor of Engineering at Columbia University and a WtE proponent, has stated, America’s dependance on the use of landfills and resistance to constructing new WtE plants is economically and environmentally irresponsible (4).
  • Our dependance on numerous landfills, oil drilling, hydraulic fracturing for natural gas, and nuclear power with it’s production of radioactive waste, raise the risk of significant harm to public and environmental health through contamination of air, soil, water used for agriculture and drinking, underground aquifers, the marine environment and seafood that we eat.
  • Radioactive tritium has leaked from three-quarters of U.S. commercial nuclear power sites, often into groundwater from corroded, buried piping, an Associated Press investigation shows. Tritium is a radioactive form of hydrogen. It has leaked from at least 48 of 65 sites. Nuclear power plants in Vermont and  Oyster Creek, Lacey Township, NJ have been leaking radioactive tritium for years which is posing a risk of contamination for aquifers.
  • What happened at Fuchushima Daiichi, Japan could happen here in the United States. A number of our own nuclear power plants are aging, lacking proper safe guards, situated on or near major earthquake fault lines, or at risk of flooding during a severe storm or terror attacks.
  • Hydraulic fracturing for natural gas has been associated with water pollution in Wyoming and Pennsylvania, as well as seismic activity in 5 states: Arkansas, Colorado, Oklahoma, Texas, and Kansas, and may have contributed to the August 25, 2011, 5.6 Richter scale, earthquake that affected the northeastern U.S.
  • ModernWtE plants cost far less to build, maintain, and repair when things go wrong, than natural gas hydraulic fracturing and oil drilling apparatus and nuclear power plants, and pose far less risk to air, water, and soil quality, environmental and public health.

 

References:

  1. Chandel, Munish K.; Kwok, Gabriel; Jackson, Robert B.; Pratson, Lincoln F. ” The potential of waste-to-energy in reducing GHG emissions.”  Carbon Management: 3(2). pp. 133-144. 2012 (Source: [PDF] The potential of waste-to-energy in reducing greenhouse gas (GHG) emissions. biology.duke.edu/jackson/cm2012.pdf).
  2. “Copenhagen: Waste-to-Energy Plants.” Danish Architecture Center. 10/03/12. (Source: www.dac.dk/en/city-projects/…/copenhagen-waste-to-energy-plants).
  3. “Municipal Waste-to-Energy Process: Top 10 benefits we can share.” 09/15/13. (Source: bionomicfuel.com).
  4. Rosenthal, Elisabeth. “Europe Finds Clean Energy in Trash, but U.S. Lags.” The New York Times. April, 12, 2010. ( Also posted at: “Europe Finds Cleaner Energy Source by Burning Trash.” www.nytimes.com/2010/04/13/science/…/13trash.html).
  5. Thorneloe S.A., Weitz K., Jambeck J. “Application of the U.S.Decision Support Tool for Materials and Waste Management.” Waste Management Journal. August, 2006.
  6.  “UK ESW Review of research into health effects of Energy from Waste facilities.” Environmental Services Association (ESA), UK, commissioned AEA Technology Plc to undertake an independent scientific review of published research on the health effects and environmental issues of Waste-to-Energy (WtE) facilities01/03/12. (Source: http://www.esauk.org/energy recovery/EfW Health Review January 3, 2012 FINAL.pdf)UK – ESA Review of research into health effects of Energy from Waste facilities).
  7. “US EPA: Methane Sources and Emissions.” Environmental Protection Agency. (Source: www.epa.gov/methane/sources.html [Accessed 2 December 2010]).
  8. “Waste-to-Energy.” Energy Aware Organization. 2006-2012. (Source: www.getenergyaware.org/energy-waste-energy.asp).
  9. “Waste-to-Energy and Health Risk Assessments.” Wheelabrator Technologies Inc.: A Waste Management Company. (Source: opalapower.com/env/wte-Health.pdf).
  10. “Waste-to-Energy: Hand in Hand with Recycling.” Confederation of European Waste-to-Energy Plants (CEWEP). (Source: www.cewep.eu/whatiswastetoenergy/wtefag/index.html).
  11. “Waste-to-Energy Reduces Greenhouse Gas Emissions.” (Source: energyrecoverycouncil.org/waste-energy-reduces-greenhouse-gas-emissions).

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