JULY 2010

Waste-to-energy ignorance slows growth Click to Enlarge - Covanta’s Alexandria/Arlington Resource Recovery Facility began commercial operation in February 1988 and serves about 300,000 residents of the County of Arlington and the City of Alexandria, which jointly own the site.
E-mail the author

The main barrier holding back the building of waste-to-energy (WTE) plants in the United States is a misunderstanding of facts among the general population. Mention burning garbage to generate energy and the reaction is usually negative because people envision stinking, billowing black smoke and ash falling on their heads – unenlightened heads. They are thinking of old fashioned, dirty incineration where burning only serves to reduce mass with no energy harvest.

Incineration has come a long way. Today, municipal waste combustion units (MWC) are in compliance with the Clean Air Act for Maximum Achievable Control Technology (MACT). A United States Environmental Protection Agency (EPA) memorandum issued in 2007 actually called MWC-MACT performance “outstanding.”

Disposal of waste by burning dates back to man’s first use of fire, but it was not until 1975 that burning solid waste to generate energy became commercially viable in the United States. That’s when the first commercial plant opened. It still operates in Saugus, Massachusetts.

Over the intervening 35 years, the industry has advanced its technology considerably and developed pollution controls that make it one of the cleanest forms of energy generation. We asked Paul Gilman, chief sustainability officer at Covanta Energy about pollution: “We produce electricity with fewer emissions than coal and oil, and most of our plants emit less than natural gas facilities. In some plants we tie natural gas.” 

Covanta is the largest WTE company in North America with 41 plants in 16 states and one in Canada. In North America they annually process more than 20 million tons of municipal solid waste to generate over 10 billion pounds of steam and approximately 9 million megawatt-hours of electricity.

If Americans knew the facts about using WTE plants as compared to landfilling, or burning coal, oil or natural gas, public attitude could be changed. The EPA actually stated that our nation’s 86 waste-to-energy plants produce electricity with less environmental impact than almost any other source of electricity.

Unlike coal, oil, natural gas or nuclear, WTE is classified as renewable energy under the Energy Policy Act of 2005 and by the Department of Energy (DOE). Twenty-five states plus the District of Columbia have laws that define WTE as renewable energy and 15 states include WTE in renewable energy portfolios (state policies mandating electricity providers get a percentage of their power from renewable resources by a certain date). Five states have set nonbinding renewable energy targets.

DOE says turning garbage into energy makes “important contributions to the overall effort to achieve increased renewable energy use and the many associated positive environmental benefits.”

Generally speaking, however, people do not understand the benefits of converting solid waste into power, nor the state of the American industry.

The New York Times published a story in April entitled, “Europe Finds Clean Energy in Trash, but U.S. Lags.” The article told how Europe has embraced WTE, has about 400 plants, is expanding existing facilities and building new ones. The article covered positive aspects of WTE, but erred in one important statement: “By contrast, no new waste-to-energy plants are being planned or built in the United States…”

Ted Michaels, president of the Energy Recovery Council, the trade organization representing the United States waste-to-energy industry, wrote a letter to the Times editor (as yet unpublished) that said in part: “…I would take issue with the assertion that there are no new waste-to-energy facilities being planned or constructed in the United States. On the contrary, the United States has seen a resurgence of interest in waste-to-energy and new capacity has been planned and constructed.”

Michaels cited expansions within the past three years of two facilities, each of which added over 50 percent capacity to meet new demand. Other expansions are currently underway in Hawaii and New York, two in Minnesota and several more are being considered at other locations. New facilities have been proposed and are underway in Florida and Maryland. Other facilities are being actively considered in many parts of the country, including plants in Los Angeles and Chester County, South Carolina. Michaels concluded his letter with: “While these facilities will take time to wind their way through the necessary processes, it is clear that waste-to-energy is on the rise in the United States and we will begin to close the gap with our European counterparts.”

“Europe tends to focus less on generating electricity and more on district heating and cooling. In Europe, community-based plants primarily feed hot water into buildings, whereas in the United States it is used to generate electricity to feed into the grid,” Michaels explained.

Nonetheless, both the EPA and the European Commission’s Eurostat estimate that the European Union (EU) annually sends 50 million metric tons to WTE plants while the United States sends about 26 million metric tons. The disparity is less considering that the EU-27 have a population of nearly 500 million and the United States about 300 million. The EU also aggressively discourages landfills through taxation while in the United States landfills are still relatively cheap, but getting more expensive. “When we construct a facility we are in effect competing with landfills. So we have to have a fee that is competitive as well as utilize revenues we get from recycling metals and the energy sales,” said Gilman of Covanta’s business model.

Covanta broke ground in December for a 40 percent expansion of the plant it operates for the city and county of Honolulu to process an additional 900 tons a day and recently completed a 600 ton per day expansion at the plant it operates in Hillsborough County, Florida. As landfilling continues to present environmental challenges, communities across North America are exploring alternatives.

Maryland recently awarded contracts for two new WTE plants. West Palm Beach, Florida has issued a request for proposals. “We have a community in South Carolina that is interested in a facility and we are talking to the City of Vancouver where we operate their existing WTE facility about a new project where there is no guarantee on waste delivery. The plan is to barge the waste, which is better than long haul trucking. We are essentially saying that whatever you have left over after recycling we will take it. Then the burden of risk is on us to keep the fuel supply going by working with other communities. Increasingly, it’s about working with groups of communities,” said Gilman.

It appears that countries and communities with more progressive recycling programs better understand the interrelation of energy production, recycling and effects on the environment. “The communities we serve have recycling programs with greater recovery rates than the United States national average. Some communities we serve like Marion County, Oregon have a recycling rate over 60 percent and a target of 70, ” Gilman explained.

More advanced municipal recycling operations do a good job of separately recovering plastic, paper and metal, but invariably some of these materials wind up in the garbage going to WTE plants – a composition of roughly two-thirds biomass and one-third fossil based. The plants use waste as fuel to recover the energy value. In the process, the original volume is reduced to a 10 percent residue. Covanta calculates its residue at 22 percent ash, which is landfilled, and 78 percent metal that is recycled. The Energy Recovery Council estimates that over 700,000 tons of ferrous is recovered from United States WTE plants annually. But there is a trend towards more nonferrous recovery.

Gilman told us about metals at Covanta. “We process about 20 million tons of municipal solid waste every year. About 98 percent of that waste has ferrous recovery and about 60 percent has nonferrous recovery. For 2010 we project to do about 15 thousand tons of nonferrous and about 430 thousand tons of ferrous. Of waste by weight going through our plants it’s about 2.6 percent metals.”

Water heated by combustion is converted into steam that drives turbines to generate electricity. Using a multi-step pollution control system, WTE plants employ scrubbers to control acid gas, fabric filters to control particulate, selective non-catalytic reduction to control nitrogen oxides and carbon injection to control mercury and organic emissions to meet strict standards. Covanta claims that it operates, on average, at about 80 percent below permitted levels.

The Energy Recovery Council said that for every ton of waste processed in a WTE plant nearly one ton of greenhouse gas (GHG) is avoided. This calculation is complex, but based on the EPA’s Municipal Solid Waste Decision Support Tool, modern waste-to-energy plants help reduce greenhouse gases three different ways:

1. When a ton of solid waste is delivered to a waste-to-energy facility, the methane that would have otherwise been generated in a landfill is avoided. While some landfill methane is collected and burned to generate electricity, the vast majority is emitted into the atmosphere.

2. For every megawatt of electricity generated through the combustion of solid waste, a megawatt of electricity from a conventional coal or oil-fired plant is avoided, creating a net savings of GHG emissions.

3. A modern WTE facility separates ferrous and nonferrous metals, which are recycled. This is more energy efficient than mining and processing virgin materials, saves the required energy and avoids GHG emissions.

There are other pluses. For every ton of domestic waste processed, the United States avoids the need to import one barrel of oil, or mine a quarter ton of coal. Since WTE plants are usually located near large metropolitan areas with high volume waste generation, shorter hauls are required. This reduces costs for long-distance trucking, highway congestion and transportation emissions.

Covanta instituted a preventative program two years ago to help keep mercury out of solid waste. By working with the communities it serves, the company offers a $5 gift card to consumers who turn in mercury thermostats, or elemental mercury. In 2009, over 500 pounds of mercury was preempted from their WTE plants.

With tipping fees rising, more complex and costly EPA landfill GHG regulations in the offing and the high costs of transportation, it seems a waste to waste solid waste when WTE is a proven green technology that is becoming cleaner as it progresses.

In this exploration of waste to energy it is apparent that the industry and government agencies need to better inform the public that WTE is one of the more intelligent environmental choices.