FREDERICK COUNTY, Md., wants to reduce the use of fossil fuels to produce electricity for its homes and businesses. Currently, 90 percent of the county's electricity comes from coal-fired power plants, while solar, wind and geothermal power produce the other 10 percent. Now, county officials want to add garbage as another alternative power source.
The county has asked the Northeast Maryland Waste Disposal Authority (NMWDA) to bid out a 40-megawatt waste-to-energy (WTE) plant that would be located in the city of Frederick. The plant would produce enough electricity to heat, cool, light and run appliances for about 20,000 homes, or around 25 percent of the 83,000 housing units in the county. In all, the plant would supply about 5 percent of the electricity used in the county and drive the percentage derived from coal down to 85 percent.
It would represent a slight, but measurable, move toward reducing the county's reliance on an increasingly expensive and sometimes unreliable supply of fossil fuels. Equally important, Frederick County's plan also would help to reduce the greenhouse gas emissions that are blamed for global warming.
If NMWDA builds the WTE plant, it would become the first such plant constructed in the United States since 1996. Coincidentally, the last plant was built in Montgomery County, Md., not far from Frederick.
After a decade of decline, the WTE industry may be on the rebound, the result of the nation's burgeoning interest in using alternative energy and curbing greenhouse gas emissions. “We've become too dependent on fossil fuels, and we have to think about alternatives,” says David McCary, director of solid waste and environmental programs for Tampa, Fla. “We've been in the business of WTE for two decades, and I'd like to see more legislation that supports WTE facilities as a renewable energy.”
Others also see a growing demand for WTE sites. “We're bullish on the industry,” says Ben Gilbert, Jr., vice president of business development with New York-based Veolia ES Waste-to-Energy, a division of Veolia Environmental Services. “We believe that market forces are changing.”
The Rise and Fall
The WTE industry arose in the late-1980s and grew rapidly through the mid-1990s. At its high point, 103 WTE plants operated in the United States. The WTE business model relied on tax incentives and ordinances that required haulers to supply the plants with solid waste.
However, during the 1990s, large regional landfills, located far from densely populated areas, sprang up across the country, Gilbert notes. WTE sites found it hard to compete with the landfills because low diesel fuel prices made it economical for haulers to ship trash long distances.
Furthermore, the U.S. Supreme Court's 1994 ruling that struck down a local government's flow control law made would-be WTE site builders worry that they could not guarantee a supply of solid waste to their facilities. Add in new federal clean air regulations requiring expensive pollution control technology, and, by the mid-90s, expansion in the WTE industry had effectively come to a halt. Today, 88 WTE plants continue to operate in the United States.
Opponents of WTE facilities cite concerns about dioxin emissions and argue that the sites detract from practices that they say are more environmentally friendly, such as recycling, composting and source reduction.
In recent years, however, WTE industry members and the federal government have insisted that the facilities are safe. According to the U.S. Environmental Protection Agency (EPA), the industry has installed $1 billion worth of pollution control technology.
In a 2003 letter to the Washington-based Integrated Waste Services Association (IWSA), which represents the WTE industry, EPA endorsed WTE plants as a “clean, reliable, renewable source of energy.” According to the letter, WTE plants “produce 2,800 megawatts of electricity with less environmental impact than almost any other source of electricity.”
“WTE is a very clean form of energy,” says Robin Davidov, executive director of the NMWDA, the organization overseeing the new WTE plant for Frederick County, Md. “We have not been able to stand still like coal-fired plants. We have had to continue to upgrade.”
Davidov says the performance of the county's plant will exceed the Maximum Achievable Control Technology standards established by the federal Clean Air Act and will meet the stricter standards set for WTE in the European Union.
Promoting its facilities as a way to reduce emissions is a key part of the WTE industry's rebound strategy. According to EPA, nearly one ton of carbon dioxide equivalent emissions are avoided for every ton of municipal solid waste handled by a WTE plant.
IWSA says three factors contribute to this exchange. First, a ton of solid waste burned in a WTE facility is a ton of waste that does not produce methane, which is considered a cause of global warming, in a landfill. While some landfill methane is burned to produce energy, an undetermined amount escapes into the atmosphere.
Second, the process of generating electricity in a WTE facility does not produce carbon dioxide emissions like the process in a fossil fuel-fired power plant. Finally, according to IWSA, WTE plants recover more than 700,000 tons of ferrous metals for recycling annually. Recycling metals saves energy and avoids carbon dioxide emissions that would have been made if virgin materials were mined and new metals were manufactured.
Like solar power and wind power, WTE also has earned status as a renewable form of energy from the federal and state governments. While some question the renewable energy tag for WTE, the industry says its case is strong. “The definition of renewable is that it has to be sustainable and indigenous — that is, home grown,” says Ted Michaels, president of IWSA. “Renewable fuel is also defined as something that can't be depleted. Depending on the data that you look at, WTE currently uses between 8 percent and 13 percent of the solid waste produced in the United States. Since more is produced every year, you can say that solid waste cannot be depleted.”
State and federal governments seem persuaded about the renewable status of solid waste. According to IWSA, 23 states have so far defined energy generated from waste-driven power plants as renewable energy. In addition, the federal government has recognized waste as a renewable fuel in federal laws, executive orders and regulations, starting with the Public Utility Regulatory Policy Act (PURPA) of 1978 and continuing with the Energy Policy Act of 2005.
A Landfill Alternative
Tampa, Fla., has been burning trash for energy since 1985. The city's plant, which is operated by Wheelabrator Technologies Inc. of Hampton, N.H., has four furnace units and boilers. Each unit burns 250 tons of trash per day, totaling 1,000 tons per day. The boilers produce steam that turns a turbine, which generates 22.5 megawatts of electricity. That's enough electricity to light, heat and cool 15,000 homes in Tampa, about 12 percent of the city's 125,000 households.
“The plant burns 330,000 tons of trash per year — all the trash we collect that is burnable,” says Greig Grotecloss, the city's WTE manager. “We landfill 25,000 to 40,000 tons per year, materials that aren't processable.”
According to Nancy McCann, Tampa's urban environmental coordinator, communities build WTE plants to dispose of trash, not to generate electricity. “Selling the energy helps pay for the trash disposal,” she says.
Tampa earns about $8 million per year in electricity revenues. The operating budget for the plant is $20 million per year, including interest on the bonds used to finance the facility as well as the operations and maintenance fees charged by Wheelabrator. Tipping fees make up the difference.
In recent years, cost and revenue pieces of the WTE puzzle have fallen into place as diesel fuel prices have doubled, giving haulers a reason to start tipping trash at local WTE facilities again and giving WTE producers more valuable electricity to sell. The cost of landfilling Maryland waste in Virginia was inexpensive until three years ago, Davidov says. But prices have surged recently, reflecting the competition to get into large regional landfills.
“We've always known that when the price for transfer and disposal to a landfill rose to equal the cost of building a new WTE plant, that is what we would do,” Davidov says. “On a graph, those lines crossed two years ago. In other words, over a period of 20 years, it will cost the same to build and operate a WTE plant as it will cost to transfer and dispose of waste at out-of-state landfills.”
Ten years ago, WTE facilities were thought of first and foremost as a waste disposal option. The production of energy was a secondary matter. But the economic model has changed.
When NMWDA opened its Montgomery County, Md., facility in 1996, revenues from electricity production were $3 million per year. Compared to debt service and operating costs, $3 million was “nothing,” Davidov says.
Today, however, NMWDA earns revenues of approximately $20 million on the electricity produced by the Montgomery County facility, almost equal to debt service. “When that happens, you stop thinking about this as just a place to dump your trash, and you start thinking about it as an energy source,” Davidov says. “We are very focused on that, and that is a big reason for building new plants.”
East Coast Bias
The lion's share of the country's WTE plants is on the East Coast, with most located in the densely populated Northeastern states. “In less populated areas, land is less expensive, and you can build a landfill with low tipping fees,” says Derek Porter, director of corporate communications with Covanta Energy Corp. in Fairfield, N.J. “But in the major urban areas from Washington, D.C., to Boston, where land is extremely expensive and there isn't a lot of it available for development, the economics are dramatically different. In these areas, a municipality might have to haul waste 500 miles to get into southern Virginia, western Pennsylvania, West Virginia or Ohio. And the cost of transportation and disposal are very unstable today.”
Porter expects WTE growth to occur mostly on the East Coast, with the first wave of new construction coming from expansions of existing plants, which is already happening. Recently, Covanta began two expansions at its Florida facilities in Hillsborough and Lee counties. Both are adding nearly 600 tons per day of additional capacity, which will enable each to produce an additional 18 megawatts.
With expansions of existing WTE plants underway, the next step will be new plant construction. In addition to the proposed facility in Frederick County, at least three more plants are under consideration, perhaps signaling the start of a new era in WTE.
Michael Fickes is a contributing writer based in Westminster, Md.