Executive Summary
Highlights
The biomass power industry is undergoing a new surge of growth in the United States. While
bioenergy has traditionally been used by certain sectors such as the paper-making industry, more
than 70 new wood-burning plants have been built or are underway since 2005, and another 75
proposed and in various stages of development, fueled by renewable energy subsidies and federal
tax credits. In most states, biomass power is subsidized along with solar and wind as green,
renewable energy, and biomass plant developers routinely tell host communities that biomass
power is “clean energy.”
But this first-ever detailed analysis of the bioenergy industry reveals that the rebooted industry is
still a major polluter. Comparison of permits from modern coal, biomass, and gas plants shows
that a even the “cleanest” biomass plants can emit > 150% the nitrogen oxides, > 600% the volatile
organic compounds, > 190% the particulate matter, and > 125% the carbon monoxide of a coal
plant per megawatt-hour, although coal produces more sulfur dioxide (SO2
). Emissions from a
biomass plant exceed those from a natural gas plant by more than 800% for every major pollutant.
Biomass power plants are also a danger to the climate, emitting nearly 50 percent more CO2 per
megawatt generated than the next biggest carbon polluter, coal. Emissions of CO2
from biomass
burning can theoretically be offset over time, but such offsets typically take decades to fully
compensate for the CO2
rapidly injected into the atmosphere during plant operation.
Compounding the problem, bioenergy facilities take advantage of gaping loopholes in the Clean Air
Act and lax regulation by the EPA and state permitting agencies, which allow them to emit even
more pollution. Electricity generation that worsens air pollution and climate change is not what
the public expects for its scarce renewable energy dollars.
Our examination of 88 air emissions permits from biomass power plants found:
Although biomass power plants emit more pollution than fossil fueled plants, biomass plants
are given special treatment and are not held to the same emissions standards. A double
standard written into the Clean Air Act allows biomass power plants to emit two and a half
times more pollution (250 tons of a criteria pollutant) than a coal plant (where the
threshold is 100 tons) before being considered a “major” source that triggers protective
measures under the Clean Air Act’s Prevention of Significant Deterioration (PSD) program
– even though the pollutants, and their effects, are the same.
Almost half of the 88 biomass facilities we analyzed avoided PSD permitting altogether by
claiming they will be “synthetic minor” sources, even though in many cases their size
indicates that they should be regulated as major sources of pollution, subject to the PSD
program. Minor source permits are issued by the states and contain none of the protective
measures required under federal PSD permitting. Despite the widespread use of this end-6
run around pollution restrictions, the EPA chooses not to review most state-issued minor
source permits.
The biomass power industry is increasingly burning contaminated fuels, blurring the lines
between renewable energy that has been portrayed as “clean,” and waste incineration.
While most biomass power plants burn forest wood as fuel, the majority of the permits we
reviewed also allowed burning waste wood, including construction and demolition debris.
EPA rules allow biomass plants to emit more heavy metals and other hazardous air
pollutants (HAPs) than both coal plants and waste incinerators, and again, the use of
“synthetic minor” status is widespread, with facilities of all sizes claiming to be minor
sources for HAPs with little support, verification, or proof. An EPA rollback on regulation
that allows more contaminated wastes to be burned as biomass, rather than disposed of in
waste incinerators with more restrictive emissions limits on air toxics, will only increase
toxic emissions from the bioenergy industry.
Because of this perfect storm of lax regulation and regulatory rollbacks, biomass power plants
marketed as “clean” to host communities are increasingly likely to emit toxic compounds like
dioxins; heavy metals including lead, arsenic, and mercury; and even emerging contaminants, like
phthalates, which are found in the “waste-derived” fuel products that are being approved under new
EPA rules. Permissive emission standards for biomass plants mean that these pollutants can be
emitted at higher levels than allowed from actual waste incinerators. As such, it is not a stretch to
conclude that biomass plants being permitted throughout the country combine some of the worst
emissions characteristics of coal-fired power plants and waste incinerators, all the while professing
to be clean and green.
Detailed findings
Biomass power plants are disproportionately polluting not just because of their low efficiency (in
converting heat to electrical output) and high emissions inherent in burning wood for energy, but
also because the bioenergy industry exploits and actually depends on important loopholes in the
Clean Air Act and its enforcement, loopholes that make bioenergy far more polluting than it would
be if it were regulated like fossil fuels. Our review of 88 air permits of biomass power plants
tabulated information on facility size, fuel use, pollution control technology, and allowable
emissions. Some of the facility permits were issued under the Prevention of Significant
Deterioration (PSD) program in the Clean Air Act, which requires “major sources” of pollution to
reduce emissions by conducting a the Best Available Control Technology (BACT) analysis, and also
requires facilities to conduct air quality modeling that assesses whether they will violate EPA’s air
quality standards and threaten health.
We contrasted permits that had gone through PSD with permits for “minor” sources, which are
issued by the states and local agencies with little to no EPA (and public) oversight and contain none
of the measures that PSD permits require to nominally protect air quality. We found that permits
issued by states allowed biomass power plants to emit about twice as much pollution as plants with 7
permits issued under the PSD program, and that state-issued minor source permits also dodged
controls on high rates of emissions, for instance during plant startup and shutdown when pollution
controls are frequently bypassed. Periods of intense emissions from facilities can present an
elevated health risk because even short episodes of elevated air pollution are associated with acute
adverse health effects such as asthma attacks, heart attacks, and stroke.
Loophole 1: Biomass plants can emit more pollution before triggering federal
permitting
The biggest factor allowing bioenergy facilities to receive lax state-level minor source permits
instead of PSD permits is a key loophole in the Clean Air Act that gives special treatment to
biomass plants. While fossil-fueled power plants are considered major sources that are required to
go through PSD if they emit 100 tons of a pollutant per year, a biomass plant is allowed to emit 250
tons of a pollutant before PSD permitting applies. The pollutants regulated by the law are the same
– they have the same effect on health – but bioenergy plants are allowed to emit two and a half
times the pollution of a fossil fueled plant before PSD permitting is triggered. As all but five (94
percent) of the 88 facilities for which we have permits in our database would emit more than 100
tons of a criteria pollutant, this single loophole is responsible for nearly doubling the amount of
pollution that the emerging bioenergy industry is allowed to emit (because in general, minor source
emissions limits are about twice the limits set in PSD permits).
The fix: Burning biomass for electricity produces as much or more of key pollutants as coal – so
biomass should be regulated like coal. EPA has the authority to require that biomass plants be
added to the list of pollution sources where PSD permitting is triggered at 100 tons. Biomass
power plants are big, polluting facilities that emit hundreds to thousands of tons of pollution each
year. They should be regulated accordingly.
Loophole 2: EPA’s free pass for bioenergy CO2
lets large power plants avoid
regulation
When EPA began regulating CO2 under the Clean Air Act, this provided an opportunity to reduce
pollution from the bioenergy industry, had EPA chosen to take it. Under the implementation of
the Tailoring Rule, if a facility was a major source for CO2
(emitting 100,000 tons per year), PSD
permitting would be triggered, including air quality modeling and a best available technology
(BACT) analysis not just for CO2
, but criteria air pollutants as well. Since nearly every biomass
power plant larger than about 8 MW has the potential to emit at least 100,000 tons of CO2 per
year, the decision by EPA to exempt bioenergy CO2 emissions from regulation under the Clean Air
Act for a period of three years greatly increased the potential for pollution from the emerging
bioenergy industry. This exemption provides the majority of recently permitted biomass plants
another means to avoid the protections afforded by PSD permitting. Although EPA’s exemption
for bioenergy CO2 emissions was found to be unlawful by the U.S. Court of Appeals, the Agency
has not implemented the Court’s decision and reversed the exemption. 8
The fix: EPA should regulate bioenergy CO2 now. Once in the PSD program, the best available
control technology analysis stage provides an opportunity to discuss how biomass facilities can
reduce their net emissions of CO2.