WTE - Waste-to-Energy   

Humans generate over 2.1 billion tons of municipal waste annually. Most of this waste is transported to landfills, where it sits, decays, and releases a suite of environmental pollutants.  But an alternative solution is converting it into energy. Locked inside the 2.1 billion tons of municipal waste that we generate each year is approximately 24.5 quadrillion Btu of energy, enough heat to meet about 10% of global annual electricity consumption.    In the USA  we throw away about 245 million tons of waste annually, 62% more than we did in 1960. This is termed MSW - Municipal Solid Waste. While Zero Waste remains the prime objective, waste must be currently either landfilled or burned in waste-to-energy incinerators. Particularly in Europe and Asia, WTE is the accepted preference when it comes to reducing the greenhouse emissions resulting from our consumption habits.

March 9 2011: Newer WTE technologies forecast to grow rapidly. According to the most recent data available from the International Energy Agency, from 2000 to 2006, global waste to energy power production from municipal and industrial wastes increased from 283 terawatt hours to 383 terawatt hours, a 35% increase over that period. SBI Energy recently evaluated waste to energy technologies, including incineration, gasification, plasma gasification, pyrolysis, and anaerobic digestion.  SBI Energy’s in-depth analyses of the global market forecasts the market will increase from approximately $9 billion in 2011 to $27 billion by 2021, equivalent to a CAGR of 11%. Historically speaking, 95% of the global waste to energy market was dominated by two technologies: incineration and anaerobic digestion. But with new advances, other technologies, specifically pyrolysis, plasma gasification, and gasification, will gain market share and together will comprise over 30% of the total waste to energy market by 2015. link

AD - anaerobic digestion. The most common waste-to-energy applications in the U.S. include the combustion of municipal solid waste (MSW), landfill gas-to-energy, and the digestion of farm waste or waste water. An often overlooked waste-to-energy resource, however, is mixed organic waste (for example, food and yard waste) anaerobic digestion (AD). AD technologies comes in a variety of shapes and sizes, so for now, we've used assumptions provided by a dry fermentation (that is a digester that accepts higher-solids waste) technology provider. The EPA estimates that in 2008, 250 million tons of municipal solid waste (including organic and non-organic) was generated in the U.S. While 22 million tons of organic waste was diverted for composting, an estimated 43 million tons of organic waste was sent to landfills. The total electric and thermal power (assuming a combined heat and power application) associated with this organic waste is approximately 1 GWe, equivalent to serving close to 1 million homes. While composting may appear to be a direct competitor to AD for organic waste, the two are mutually beneficial because remaining digestate from the AD process can be composted and sold. link

         Below:  

• Landfill problems
• Waste-to-energy incineration
• Europe & Asia
  
• Zero-waste
• 
  

This Energy Recovery Council web page answers some frequently asked questions: Are wte facilities safe for the environment? How do wte facilities affect greenhouse gases? What about other toxins and ash? Is wte a renewable energy source? Do wte plants pose dangers for people living nearby? Does wte compete with recycling?

March 2011: Garbage: to burn or bury? Europe burns heaps of garbage, getting lots of electricity and some heat. The United States does not. This Renewable Energy World article looks at some of the conflicting issues, but asserts that,  " . . . landfills produce 1.6 to 5.7 times more greenhouse-warming as waste-to-energy to make the same amount of electricity."  link

Landfill problems

According to the Environmental Protection Agency, the average American produces about 4.4 pounds of garbage a day, or a total of 1,600 pounds a year. (The US total is therefore close to 250 million tons per year.) This only takes into consideration the average household member and does not count industrial waste or commercial trash. If this sounds like a staggering number, you would be surprised to know that Americans are not the number one producers of garbage in the world. In Mexico, the average household produces 30% more garbage than in America. link   (EPA: There are about 87 waste-to-energy plants in the United States that generate electricity. In 2008, these plants generated 14.5 million kilowatt hours of electricity, about the same amount used by 1.3 million U.S. households.link)

Landfilling is one of the most common ways of municipal solid waste (MSW) disposal in developing countries. Air pollutants emitted from landfills contributes to the emission in the atmosphere of greenhouse gases and cause serious problems to human health. Methane emissions from landfills is a serious environmental global concern as it accounts for approximately 15% of current greenhouse gas emissions. Landfilling is a significant contributor to greenhouse gas emissions accountable for approximately 5% of total ghg releases which consists of methane from anaerobic decomposition of solid waste and carbon dioxide from wastewater decomposition. Landfills are among the nation's largest emitters of methane. link

According to a directive from the European Union, landfilling of combustible materials must be phased out within the decade. However, it is not clear that the capital investments required will be made by all of the member countries. Some of them have little WTE capacity and some - for example, Greece - none at all. The use of WTE amounts to 142 lbs per capita in Japan, 115 lbs in Singapore, and 48 lbs in the US. One of the newcomers to WTE is China, with seven plants in operation and an estimated annual capacity of 1.6 million metric tonnes per year.  link

Landfill recovery. The EPA says " . .even the best liner and leachate collection system will ultimately fail due to natural deterioration, and recent improvements in containment technologies suggest that releases may be delayed by many decades at some landfills. For this reason, the EPA is concerned that while corrective action may already have been triggered at many facilities, 30 years may be insufficient to detect releases at other landfills."   link     All landfills will eventually fail and leak leachate into ground and surface water. Plastics are not inert. State-of-the-art plastic (HDPE) landfill liners (1/10 inch or 100 mils thick) and plastic pipes allow chemicals and gases to pass through their membranes, become brittle, swell, and break down. The U.S. has 3,091 active landfills and over 10,000 old municipal landfills, according to the Environmental Protection Agency.  link 

Waste-to-energy incineration

Overview of WTE. While some people still confuse modern waste-to-energy plants with incinerators of the past, the environmental performance of the industry is beyond reproach. Studies have shown that communities that employ waste-to-energy technology have higher recycling rates than communities that do not utilize waste-to-energy. The recovery of ferrous and non-ferrous metals from waste-to-energy plants for recycling is strong and growing each year. In addition, numerous studies have determined that waste-to-energy plants actually reduce the amount of greenhouse gases that enter the atmosphere. Nowadays, waste-to-energy plants based on combustion technologies are highly efficient power plants that utilize municipal solid waste as their fuel rather than coal, oil or natural gas. Waste-to-energy plants recover the thermal energy contained in the trash in highly efficient boilers that generate steam that can then be sold directly to industrial customers, or used on-site to drive turbines for electricity production. WTE plants are highly efficient in harnessing the untapped energy potential of organic waste by converting the biodegradable fraction of the waste into high calorific value gases like methane. The digested portion of the waste is highly rich in nutrients and is widely used as biofertilizer in many parts of the world.    link   (EPA: There are about 87 waste-to-energy plants in the United States that generate electricity. In 2008, these plants generated 14.5 million kilowatt hours of electricity, about the same amount used by 1.3 million U.S. households. link)    

What the EPA says on emissions:  Waste-to-energy facilities are subject to standards that are among the most stringent in the world. Under the Clean Air Act of 1970, more than $1 billion was invested in upgrades to air quality control systems at America’s waste-to-energy facilities. The results were so dramatic that the U.S. Environmental Protection Agency wrote that the “upgrading of the emissions control systems of large combustors to exceed the requirements of the Clean Air Act Section 129 standards is an impressive accomplishment.” In addition to combustion controls, waste-to-energy facilities employ sophisticated air quality control equipment.  link  

The EPA has stated that waste-to-energy plants produce electricity with "less environmental impact than almost any other source of electricity." Studies have determined that we can avoid nearly one ton of CO2 emissions for every ton of trash processed by a waste-to-energy plant rather than discarded conventionally. link

Worldwide, about 130 million tonnes of municipal solid waste (MSW) are combusted annually in over 600 waste-to-energy (WTE) facilities that produce electricity and steam for district heating and recovered metals for recycling. Since 1995, the global WTE industry increased by more than 16 million tonnes of MSW. Currently, there are WTE facilities in 35 nations, including large countries such as China and small ones such as Bermuda. Some of the newest plants are located in Asia. link    (A 'tonne' is used outside the US and is equivalent to 1,000 kg - about 2,204 lbs. A 'ton' is almost exclusively used in the US and
is 2,000 lbs.)        

WTE Emissions: In the late 1980s, WTE plants were listed by the US Environmental Protection Agency (EPA) as major sources of mercury and dioxin/furan emissions. However, in response to the Maximum Available Technology (MACT) regulations promulgated in 1995 by the US EPA, the US WTE industry spent more than one billion dollars in retrofitting pollution control systems and becoming one of the lowest emitters of high temperature processes. The US EPA recently affirmed that WTE plants in the US produce 2800 MW of electricity with less environmental impact that almost any other source of electricity. Columbia University researchers have estimated the WTE content equivalent to theoretically generating 82,000MW of electricity. link

When the greenhouse gas footprint of a waste-to-energy plant is compared to the greenhouse gas releases avoided, you discover that nearly one ton of carbon dioxide equivalents are avoided for every ton of trash handled by a waste-to-energy plant. As you can see, waste-to-energy plants are tremendously valuable contributors in the fight against global warming.  link

Environmental Benefits. Despite the great reduction in emissions attained by WTE facilities in the last 15 years, some environmental groups in the US continue to oppose new WTE facilities on principle, unaware that the only alternative for MSW disposal - landfills - have much larger environmental impacts. For every ton of waste landfilled, greenhouse gas emissions in the form of carbon dioxide increase by at least 1.3 tons. During the life of a modern landfill and for a mandated period after closure, aqueous effluents are collected and treated chemically; however, chemical reactions and volume decrease of the landfilled MSW can continue for decades and centuries. Thus, there is potential for future contamination of adjacent waters. It is for this reason that communities built on sandy soil, such as those in Long Island in New York State and the state of Florida have opted for WTE disposal of their MSW. link  (The Sierra Club opposes both landfill and incineration - link)  

Is dioxin a problem? In Europe, waste-to-energy plants are strictly controlled. They comply with the most stringent emission limit values applied to any single industry, set out in the Waste Incineration Directive 2000/76/EC. While dioxins exist naturally in the environment the manmade ones come from a variety of combustion processes including steel mills, power plants, cement kilns, diesel vehicles, buses, open fires in the home, bonfires, barbeques, jet engines, forest fires. Emissions from Waste-to-Energy plants present just a tiny fraction of such emissions. Whereas in 1990 one third of all dioxin emissions in Germany came from Waste-to-Energy Plants, for the year 2000 the figure was less than 1%. link

Europe & Asia

August 2009:  Europe leads the way on WTE. 
More evidence emerges that Europe is advancing more rapidly than other regions on the environmental front. It is the largest waste-to-energy plants market in the world, with well-developed infrastructure and more than 429 such incinerator facilities, A new analysis finds that this market earned revenue of $4.4 billion last year. The European Union's push to shift away from landfills through its Landfill Directive "has indirectly helped the waste-to-energy business" the report says. (above -  Brescia WTE facility in Italy)   link    

Denmark. According to EPA and Eurostat figures, Denmark recycles 42% of its waste and burns 54% in heat and power stations. The US, by comparison, recycles 33% while only 13% is used in waste-to-energy incinerators. The majority of US trash – 54% – ends up in landfills, compared to only 4% in Denmark.   link     More on Denmark's incinerator story here.

During 2006, 14.3% of Netherland's renewables came from WTE plants, as did 13.3% for Belgium and 12.5% in Denmark. link

To an even greater extent than in the United States, waste-to-energy has thrived in Europe and Asia as the preeminent method of waste disposal. Lauding waste-to-energy for its ability to reduce the volume of waste in an environmentally-friendly manner, generate valuable energy, and reduce greenhouse gas emissions, European nations rely on waste-to-energy as the preferred method of waste disposal. In fact, the European Union has issued a legally binding requirement for its member States to limit the landfilling of biodegradable waste. According to the Confederation of European Waste-to-Energy Plants (CEWEP), Europe currently treats 50 million ton of wastes at waste-to-energy plants each year, generating an amount of energy that can supply electricity for 27 million people or heat for 13 million people. Upcoming changes to EU legislation will have a profound impact on how much further the technology will help achieve environmental protection goals. link

Waste-to-energy in Europe - 2007 map

Zero-Waste

From ZeroWasteAmerica.org comes this definition of zero-waste:

Zero waste is a philosophy and a design principle for the 21st Century; it is not simply about putting an end to landfilling. Aiming for zero waste is not an end-of-pipe solution. That is why it heralds fundamental change. Aiming for zero waste means designing products and packaging with reuse and recycling in mind. It means ending subsidies for wasting. It means closing the gap between landfill prices and their true costs. It means making manufacturers take responsibility for the entire lifecycle of their products and packaging. Zero waste efforts, just like recycling efforts before, will change the face of solid waste management in the future. Instead of managing wastes, we will manage resources and strive to eliminate waste.     - Institute for Local Self Reliance   
 More at ecocycle.org

The Zero Waste Alliance has been formed to promote the use of Zero Waste strategies.
See ZWA

Scotland has an ambitious zero-waste program funded by the Scottish Government which aims to recycle 70% of waste by 2025. link

Pay-as-you-throw - PAYT - is one solution to reducing the amount of waste. According to EPA surveys there are now more than 7,000 communities in the United States using some form of PAYT. More here

70% of US municipal waste is buried in landfills - 108,234 tons each day are incinerated - More statistics on our waste from the Clean Air Council: see here

Recommended reading is William McDonough's book, "Cradle to Cradle, written with his colleague, the German chemist Michael Braungart, the book is a manifesto calling for the transformation of human industry through ecologically intelligent design - more

Suggested sites for WTE cewep.com  seas.columbia.edu

Also see Waste-to-Energy Research and Technology Council -   link