Waste-to-energy
ignorance slows growth by Mike Breslin
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.