Energy from Waste: Greenhouse Gas Winner or Pollution Loser?

Is waste-to-energy the best greenhouse gas fighter among electric generating technologies? Or do trash burners spew dangerous air emissions? The answer may be a surprise.

What electricity-generating technology results in net greenhouse gas (GHG) reductions, not just zero new emissions? According to the U.S. Environmental Protection Agency (EPA), it’s not nuclear, not wind, not solar.

Give up? Waste-to-energy (WTE, known to some as “trash-to-cash”), according to the EPA and a recent analysis by the Department of Energy’s National Renewable Energy Laboratory (NREL) is the only electric generating technology that actually reduces GHG emissions as it makes power. Megawatts up; GHGs down.

According to the EPA, municipal solid waste (MSW) burners, using trash and garbage to generate electricity, separating out recyclable materials, will “actually reduce the amount of [GHG emissions] in the atmosphere compared to landfilling. The savings are estimated to be about 1.0 tons of GHGs saved per ton of MSW combusted.”

The EPA bases its calculations on methane emissions from landfills. Methane is a much more potent GHG than carbon dioxide (CO2) in the short term (although methane spends less time than CO2 in the atmosphere). Burning the trash that produces methane in landfills reduces overall GHGs.

A 2011 NREL analysis looked at lifecycle GHG emissions from electricity generating technologies. It found that wind has very small lifecycle emissions, with nuclear a bit above those, followed by solar. While all of the conventional low-carbon technologies were slightly positive in terms of GHG emissions in lifecycle terms (the energy that went into making and erecting the technologies as well as emissions from operations), energy from waste was the only option that reduced GHGs. WTE projects prevent landfill methane emissions, according to NREL; the other renewable technologies simply avoid new emissions.

Clean Power Plan Would Support WTE

A little-noticed element of the EPA’s Clean Power Plan, generally seen as a way to back out coal-fired power and boost conventional renewables such as wind and solar, reflects this analysis of the ability of WTE to yield net negative GHG emissions. Paul Gillman, senior vice president and chief sustainability officer at Covanta, a leading waste management company in the U.S., told POWER that the EPA’s Clean Power Plan tells states they can consider energy from waste “as a mitigation tool” to meet requirements under the new regulations.

Covanta, with 43 WTE plants (41 in North America and two in Europe), is now pitching GHG reductions as among the reasons to employ the technology. It turns MSW into a stream of saleable recycled commodities—such as aluminum, copper, and plastics—along with electricity and process steam that can be sold to industrial users or district heating systems. All this while reducing landfill methane. Gillman notes that Europe and Asia, which signed on to the 1997 Kyoto Protocol—which the U.S. rejected and which is now a dead letter—spurred WTE for GHG reductions.

International Support for WTE

European nations that signed on to the Kyoto agreement saw WTE as a way to reduce methane-generating landfills while increasing recycling and energy production. “In Germany,” Gillman said, “less than 1% of waste goes to landfills.” Denmark has banned landfills, turning entirely to recycling and WTE for managing its waste stream (Figure 1).

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1. Not just blowin’ smoke. The Amager Resource Center waste-to-energy plant is under construction in Denmark, which has banned landfills. The plant has gained notoriety for integrating an artificial ski slope on the roof and a stack that will blow a water vapor “smoke ring” each time 250 kilograms of carbon dioxide are released. Courtesy: Bjarke Ingels Group

Compared to the U.S., European countries have greater population densities and less territory available for landfills. They often have government-owned waste management agencies, which can streamline development of landfill alternatives. In Denmark, for example, WTE plants are owned by municipalities or multiple-municipal agencies.

In Asia, particularly China, noted Gillman, the Kyoto Protocol mechanisms created an economic incentive to reduce GHGs in order to generate reduction credits saleable to the European Union countries. According to Gillman, more than 300 WTE projects are now operating in China, and more than 100 are under construction (see sidebar “World’s Largest Waste-to-Energy Plant”). China, he said, has about the same land mass as the U.S. but four times the population—a strong incentive against landfills and for WTE.

World’s Largest Waste-to-Energy Plant

China has picked two Danish architectural firms—Schmidt Hammer Lassen Architects and Gottlieb Paludan Architects—to design the world’s largest waste-to-energy (WTE) plant for the city of Shenzhen. The project would burn some 5,000 tons of municipal solid waste per day—about a third of the waste generated by the city of 20 million, reports Deezen.com, a website covering architecture and design news.

Last December, a Shenzhen construction-waste dump collapsed, killing what press accounts said were “dozens of people.” Plans for the new WTE plant quickly followed.

According to the architects’ website, the circular facility a mile in diameter will “boast a 66,000-square meter roof, two thirds of which will be covered with solar photovoltaic panels, allowing the building to generate its own sustainable supply of energy.” The circular structure of the plant (Figure 2) will include a ramp that snakes from the ground to the roof, along with a rooftop visitors center.

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2. Full circle. This design for a waste-to-energy facility in Shenzhen, China, includes a rooftop visitors center. Courtesy: Schmidt Hammer Lassen

The Deezem article quotes Chris Hardie, head of the Schmidt Hammer Lassen office in Shanghai, as saying, “The project firstly aims to provide a clean, simple and modern technical facility to deal with the city’s growing waste. At the same time it aims to educate visitors to this growing waste challenge by taking them on an elevated walkway tour of the plant that ends with a 1.5 kilometer panoramic view of both the surrounding mountains and the 66,000-square-meter roofscape that will be geared to producing actual renewable energy.”

The companies’ descriptions and the press accounts do not indicate how much electric capacity the project will provide or what the project will cost, typical of announcements out of China on developing energy projects. The project is scheduled to be operational in 2020, according to press reports.

In the U.S., land for waste disposal is cheap and plentiful. WTE plants compete with landfills for the trash disposal dollar. According to the Energy Recovery Council, the industry’s Washington-based lobbying group, the U.S. has 84 WTE plants (four are idled but able to come into service), with about 2,800 MW of baseload electricity generating capacity. The two dominant WTE companies are publicly traded Covanta, based in Morristown, N.J., with more than 40 plants, and privately owned Wheelabrator Technologies, located in Hampton, N.H., with 16 U.S. plants.

The first new WTE project in the U.S. in 20 years went into commercial operation in July 2015, in West Palm Beach, Fla., owned by the Palm Beach County Solid Waste Authority. The 95-MW facility joined an existing 20-year-old waste combustion and energy unit. A consortium of Babcock & Wilcox and KBR designed and built the new plant.

Covanta commissioned the most recent plant in North America in January this year in the Canadian province of Ontario, the Durham York project (Figure 3), which burns 436 metric tons of MSW per day to produce 15.7 MW of baseload power.

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3. Clean lines. Ontario’s Durham York 15.7-MW waste-to-energy plant burns 436 metric tons of municipal solid waste daily. Courtesy: Covanta

Wheelabrator’s latest project is the Ferrybridge “multifuel” project in North Yorkshire in the UK, a 68-MW generator burning MSW, industrial waste, and wood waste, co-located with an existing and retiring coal-fired power plant.

Challenging U.S. Economics for WTE

Why is the U.S. slow in turning waste into energy? It’s a matter of market competition, said Ted Michaels, head of the Energy Recovery Council. He told POWER, “Our industry is strong, the facilities operate well; it’s a mature, not nascent, industry. But the industry is operating in difficult economic conditions.”

WTE businesses in the U.S. face a triple economic whammy, according to Michaels. First, the chief economic driver of WTE is waste, not energy. The facilities compete against landfills. Landfills charge a tipping fee for waste delivered to their facilities. That becomes the price WTE plants must meet to divert waste from the landfill to the energy project.

“Power is a secondary function of the economics of a waste-to-energy plant,” Michaels said. “Our largest market is waste management. That’s entirely different than wind turbines, or biomass.” Michaels noted that in the U.S., “Landfills remain cheap. That’s our primary source of competition.”

To attract trash (aka fuel), a U.S. WTE project must offer a lower tipping fee than a landfill. The waste incinerators use offsetting revenues from recycling and electric generation (and industrial steam in some cases) to support their bids for the waste stream. Of late, commodity prices for materials such as metals, paper, and plastic have been historically low, undermining the ability of the recycling portion of the facility to compete against landfills.

The crash in commodities prices has been devastating to recyclers and WTE generators across the board. The Washington Postnoted last year, “In short, the business of American recycling has stalled. And industry leaders warn that the situation is worse than it appears.” Waste Management, the nation’s largest recycler, called it a “nationwide crisis.” The company, based in Houston, said its recycling division posted a $16 million loss in the first quarter of 2015, and it has shut 10 of its largest recycling facilities. The Washington Post article concluded, “A storm of falling oil prices, a strong dollar and a weakened economy in China have sent prices for American recyclables plummeting wordwide.”

On top of that, low natural gas prices have driven down the wholesale price generators of electric power can reap in competitive markets. “Natural gas is a big driver of waste-to-energy economics, lowering the price for wholesale power,” Michaels said. The global economic crash of 2008 also slowed the economy, drove down electricity demand, and cut into the price of recycled commodities.

The Environmental Debate

Environmental opposition also burdens WTE plants. Fervent opponents of the projects assert that incinerating waste produces dangerous levels of airborne pollutants such as dioxins and heavy metals, and that the resulting ash is hazardous. In Minnesota, three local groups—the Sierra Club, the Minnesota Public Interest Research Group, and Neighborhoods Organizing for Change—are trying to shut down the Hennepin Energy Recovery Center in Minneapolis, claiming it harms the environment, according to the Waste Diveonline newsletter. The Minnesota Public Utilities Commission continues to back the project. The state has nine WTE plants, the most in the region.

Claims about harms from waste incineration and energy recovery are based on outdated data, according to the industry and government regulators. The EPA has given both air emissions and ash toxicity a green light. In addition to reducing landfill methane emissions, proponents claim, WTE projects reduce CO2 emissions by shipping waste to incinerators by rail, a less–energy intensive and less–transportation intrusive approach than trucks hauling trash to landfills.

Nevertheless, opponents of waste-burning projects repeatedly raise pollution issues, such as the claims of the Global Alliance for Incinerator Alternatives (see sidebar “Maryland Rejects New Baltimore Waste-to-Energy Plant”).

Maryland Rejects New Baltimore Waste-to-Energy Plant

Maryland has traditionally been friendly toward turning trash into electricity, and the Northeast Maryland Waste Disposal Authority, a quasi-governmental group aimed at helping Maryland communities meet their waste disposal needs, has long been an advocate of waste-to-energy (WTE) projects.

Cars driving into Baltimore from I-95 and the Baltimore-Washington Parkway for over 30 years have seen a large stack, originally bearing the letters “BRESCO” down its side and, more recently, “BALTIMORE” (Figure 4). That’s the exhaust stack for a large WTE plant, commissioned in 1985, now operated by Wheelabrator Technologies, and long a target of environmental activists for alleged air pollution problems. The project has survived multiple environmental reviews over three decades.

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4. Trash power plant target of trash talk. This Maryland waste-to-energy plant has been the target of environmentalists’ claims that it causes pollution, though it has survived three decades of environmental reviews. Courtesy: Wheelabrator

A small WTE project in Harford County, north of Baltimore near the Department of Defense’s (DOD’s) Aberdeen Proving Ground, closed down last March when its lease with the DOD expired and the Pentagon chose not to renew it. The plant began operations in 1988 and attracted little local notice.

At about the same time as the Harford County plant’s lease expired, a proposal for another large Baltimore WTE project, years in the works, collapsed. The Baltimore Sun reported that the Maryland Department of the Environment told developer Energy Answers International of Albany, N.Y., that a 2010 permit for a project in south Baltimore’s Curtis Bay neighborhood was no longer valid.

The project would have been the largest in the U.S., converting some 4,000 tons of solid waste per day into 160 MW of baseload capacity. The project drew opposition from local activists, who claimed that the plant would harm schools and parks in the neighborhood, as well as homes in the area. Opponents said the project would be a prodigious producer of oxides of nitrogen and particulate pollution, although the plant would have met all federal Environmental Protection Agency NOx and particulate emissions standards.

Baltimore activist Destiny Watford last April won a $175,000 “Goldman Environmental Prize” for organizing community opposition to the WTE project, along with kudos from New York Times environment blogger Andy Revkin. The citation read, “Curtis Bay is a highly industrialized community in south Baltimore with a history of displacing people to make room for oil refineries, chemical plants, sewage treatment plants, and other facilities that emit pollution. Those left to live within breathing distance of industry have long suffered from respiratory problems such as asthma and lung cancer. In fact, a 2013 study on emissions-related mortality rates found Baltimore to be the deadliest city, with 130 out of every 100,000 residents likely to die each year from long-term exposure to air pollution.”

Ted Michaels of the Energy Recovery Council had a different take on the events in Baltimore. He told POWER that cancellation of the 2010 state license for the Curtis Bay project came because the developer hadn’t lived up to the terms of the permit. “Maryland withdrew the permit because not enough construction activity had occurred. The terms of the permit had been violated,” he said. The Baltimore Sun reported that state environmental regulators concluded that the developers of the project had not met the permit requirements for “continuous construction.”

Are activists’ objections to mass-burn technologies technically valid? In the online news site Huffington Post, science writer Shawn Lawrence Otto wrote, “Today’s waste-to-energy (WTE) plants are not your granddaddy’s trash burners. . . . Some liberal groups, like the Center for American Progress, are starting to look at the actual science and reevaluating long-held assumptions in light of new information and increasing concern over climate change. When they do, they are finding that today’s waste-to-energy plants look surprisingly good for the environment and for fighting climate change.”

Changing Fate for U.S. WTE

In the U.S., the 1978 Public Utility Regulatory Policies Act (PURPA) boosted the WTE sector because it encouraged non-utility and unconventional electric generating technologies. The act also gave birth to today’s independent power sector, largely powered by natural gas.

The 1978 law galvanized WTE projects, which were able to meet the Federal Energy Regulatory Commission’s criterion for “qualifying facilities,” giving them access to subsidized rates. Many of the WTE projects in the U.S. started up in the 1980s and early 1990s as a result of PURPA’s push for alternatives to conventional generation.

Since then, a combination of factors, including low-cost coal plants, low prices for natural gas, and a decline in demand for electricity slowed the WTE business. The collapse of the U.S. (and worldwide) economy in 2008, along with the unexpected development of fracking technologies to produce soaring natural gas production, reducing U.S. natural gas prices, put another burden on WTE economics.

A classic example occurred in Frederick County, Md., a neighbor to Montgomery County (home of pricey Washington, D.C., suburbs and a 1985-built 52-MW Covanta WTE plant burning 1,800 tons per day of trash, sitting next door to an elderly 850-MW coal-fired plant). Maryland in the 1980s adopted a policy of no new landfills in the state, which meant either local incineration or shipping waste out of state. Maryland joined a growing list of states banning local landfills. Connecticut, Covanta’s Gillman noted, “has no operating landfills.”

Fast-growing Frederick County, home of the second-largest city in the state after Baltimore, saw its decades-old landfill reaching capacity. The county signed a $471 million contract with Wheelabrator in 2008 to build a WTE incinerator, shared with nearby Carroll County. The project got the needed state permits in 2012.

By that time, the project had become politically controversial. In 2014, an opponent of the project won election as Frederick County executive. She vowed to kill the deal. The county commissioners scrapped the project, instead, signing a contract to haul the county’s solid waste to an out-of-state landfill for five years.

New Reasons to Consider WTE

What’s the future for waste-to-energy in the U.S.? It’s uncertain. WTE lobbyist Michaels notes that “31 states, the District of Columbia, and two territories have defined waste-to-energy as renewable energy in various state statutes and regulations, including renewable portfolio standards.” Twenty-two states specifically classify WTE as meeting the requirements of their renewable goals. Michaels argues that the drive for GHG reductions will yield opportunities for waste projects.

Covanta’s Gillman says businesses may push the U.S. toward more use of WTE. “Lots of businesses have been issuing sustainability goals,” he said, “and they see improvements to the bottom line. Energy conservation has been the first tier, then on-site production and water resource management. Now they’re moving in the direction of making waste management more sustainable. ‘We want to reduce our greenhouse gas footprint,’ the executives are saying. ‘Let’s look to waste.’ ”

Some businesses are also seeing waste incinerators as a source of low-cost process steam, which is common in Europe. These projects, says Gillman, “are a very reliable source of steam,” with the plants operating in continuous baseload mode. “Industries are attracted to that reliability,” said Covanta pubic information official James Regan.

In the U.S., the sector’s future may lie in rebutting and overcoming the conventional, anti-pollution mantra of local opponents to waste incineration. The liberal and environmentally oriented Center for America Progress (CAP) made its case for WTE recently: “It is environmentally unsustainable to take garbage and bury it in the ground at landfills, where it decomposes and releases potent greenhouse-gas pollution. What’s more, some trash has to be transported by diesel trucks or trains to landfills several hundred miles away, further exacerbating its pollution footprint. Though garbage is not something we tend to actively think about on a daily basis, specifically as it relates to climate change, the United States must begin developing policies to limit the environmental consequences that result from our generation of garbage.”

The path to that policy, says CAP: “The United States must begin developing national policies to deal with the waste-management problem our country faces every day. Doing so will ultimately reduce emissions that cause climate change.” ■

Kennedy Maize is a long-time energy journalist and frequent contributor to POWER.