Small landfills hold big potential
Regulatory pressure is building on those sources
emitting greenhouse gas (GHG), especially landfills, particularly
under the proposed EPA Tailoring Rule. If enacted, many small
and medium sized landfills will become major sources and subject
to New Source Review under EPA’s Prevention of Significant Deterioration
(PSD) and Non-attainment New Source Review programs if they expand
existing operations, and will be required to obtain Title V operating
permits if they do not already operate under one. Besides heavy
costs for compliance, it may lead to government mandated remediation
and unfunded costs.
Concurrently, the waste industry is fighting
hard to exempt landfills from these new regulations because unlike
industrial combustion emissions, landfill gas (LFG) is uniquely
different – a naturally generated gas, predominately methane,
produced by organic decomposition. It’s ironic that when America
is crying for energy independence and scurrying to bring more
renewable energy to the grid, that landfill gas recovery has
taken a national backseat to solar and wind generation, especially
when you take a close look at the comparative economics.
Regulatory pressure is building on those
sources emitting greenhouse gas (GHG), especially landfills,
particularly under the proposed EPA Tailoring Rule. If enacted,
many small and medium sized landfills will become major sources
and subject to New Source Review under EPA’s Prevention of Significant
Deterioration (PSD) and Non-attainment New Source Review programs
if they expand existing operations, and will be required to obtain
Title V operating permits if they do not already operate under
one. Besides heavy costs for compliance, it may lead to government
mandated remediation and unfunded costs.
Concurrently, the waste industry is fighting hard to exempt landfills
from these new regulations because unlike industrial combustion
emissions, landfill gas (LFG) is uniquely different – a naturally
generated gas, predominately methane, produced by organic decomposition.
It’s ironic that when America is crying for energy independence
and scurrying to bring more renewable energy to the grid, that
landfill gas recovery has taken a national backseat to solar
and wind generation, especially when you take a close look at
the comparative economics.
While solar and wind are non-polluting energy sources, they do
not stand on their own economically and owe their proliferation
to rebates and tax incentives. The fact that they are clean may
justify public investment, but without generous subsidies, not
many private investors in the States would put up a dime.
On the other hand, a well engineered LFG recovery and power generation
system can pay its own way, return capital investment in three
to five years and continue to earn profits for decades, even
without carbon credits and tax deductions that can add to profitability.
By doing so, GHG emissions from landfills can be converted to
energy and be added to the mix of renewables in utility portfolios.
Barry Rogers, general manager of LFG Technologies, has been converting
landfill gas into energy and installing low-emission enclosed
flares for over 25-years. His company designs, specifies, procures
equipment, constructs and starts landfill gas-to-energy projects.
Rogers works with landfills that have engineered and installed
a piped recovery system and then engineers and delivers turnkey
projects to a performance standard.
A pioneer in this business, LFG Technologies has built over 50
landfill gas recovery projects, producing over 150 megawatts
of electricity. From a GHG emissions standpoint, these projects
daily consume billions of cubic feet of landfill gas. Rogers
provided insight into the challenges. “Our primary focus is doing
something with the gas once it is recovered, create an energy
source and either put it in a pipeline or into an electrical
line. The majority of our work has been in working with utilities
to create electricity and put it into the grid.”
Environmental zealots will argue that LFG is not green enough
and should not qualify as a renewable energy source because they
characterize it is as a dirtier form of natural gas, which does
not qualify for renewable energy tax credits. LFG is approximately
50 percent methane with the remainder mostly carbon dioxide (CO2).
It also contains nitrogen, oxygen, water vapor, sulfur and contaminants,
most being non-methane organic compounds (NMOC), but these minor
constituents usually constitute less than 1 percent of LFG. Nevertheless,
LFG qualifies as renewable under the federal Production Tax Credit
(PTC) in the same category as hydroelectric, biomass and the
conversion of solid waste to energy.
The options for handling LFG are limited. It can rise into the
atmosphere and add to other greenhouse gases that many see contributing
to global warming or climate change. For larger landfills, EPA
regulations require collected landfill gases be sent to a control
device (including flaring-off the gas – thermally oxidizing gas)
capable of achieving a better than 98 percent destruction efficiency.
Storing LFG is not practical unless you clean it and convert
it to liquid natural gas (LNG) which limits it to typically larger
landfills. Burning volatile organics to destroy them seems an
obvious waste of energy albeit necessary if no alternatives to
beneficially use it are available. Burning the gas to heat water
or boil it to create steam for use in steam turbine power generation
has limited application. Cleaning LFG so it is non-corrosive
enough to put in a pipeline for end use combustion is expensive
and often impractical unless near a pipeline and a user that
A more practical, universal way to monetize LFG, particularly
for small and medium sized landfills is by pre-combustion cleaning
and treatment of the gas and using it as fuel to power either
turbines or reciprocating engines to generate electricity.
Rogers confirmed this popular option. “Our business has been
growing substantially. 2009 was our busiest year to date and
2010 is expected to be better. The primary reason is we don’t
work with landfills, rather 100 percent with utility companies.
Their driving force is to purchase a certain percentage of their
output from renewable sources to meet portfolio objectives set
by public utility commissions.”
Rogers is very busy now only because methane recovery systems
take several years to develop. “Unless the economy turns around,
we are probably going to see a slowdown in our business due to
low natural gas prices and lower demand for energy.”
LFG to electric generation make sense for several reasons. Generation
equipment can be scaled down to very small landfills, or modularly
scaled up with additional engines or turbines as landfill gas
flows increase, either due to landfill expansions or unexpected
higher flows. A flow of only 300 standard cubic feet per minute
(SCFM) with 50 percent methane can generate 800 kW of electricity.
LFG Technologies, for example, has a few small projects. One
at 300 SCFM consistently produces 600 kW per hour and unlike
wind or solar runs ‘round the clock. While systems can be as
large as 40 megawatts, most are in the three to five megawatt
How long will a landfill continue to generate methane to make
electricity? According to Mike Niemann, landfill gas program
technical director for Environmental Information Logistics, a
consulting firm to major private landfills operators and municipalities,
“From an environmental standpoint, methane will be continually
produced for 20 to 70 years or more while landfilled organic
material decomposes. For economic viability you are realistically
looking at 30 to 40 years. I’ve been working on some facilities
that have been beneficially recovering landfill gas for over
20-years and are still going strong despite the landfill being
Surprisingly, not all landfills tapped for methane have diminished
flow over time. LFG Technologies uses planning tools, but mostly
relies on experience to evaluate the economic viability of LFG
to energy projects. “There are so many variable factors we have
to be extremely conservative in our estimates. Because of the
risk structure you have to be able to recover your investment
in 5-years,” he emphasized. “It’s always easy to expand the equipment.”
EPA regulations are somewhat elastic, have opt-outs and loopholes
when it comes to mandating when an aggregate gas collection and
control system must be installed in a landfill, but generally
the tipping point is anywhere from having two to two and one-half
million tons of solid waste in place.
“EPA does provide various control options, but several thousand
landfills flare-off the gas to some degree or another. It’s the
most predominate and cheapest form of control,” said Niemann.
Once mandated, however, the landfill is unable to claim carbon
credits or trade them because the carbon offset market is based
on voluntary emission reductions. However, if the landfill uses
LFG to generate electricity they may be eligible for IRS Section
45 tax credits at $10 per megawatt hour, and perhaps renewable
energy credits (RECs) depending on state and region where the
landfill is located.
“Given that there are over 7000 landfills in the United States
and only about 500 energy recovery facilities, the potential
is quite large, but economics play a big role in the development
of viable projects at smaller facilities. Capital expenditures
can be quite large and once a landfill closes its potential gas
production declines. Micro turbines have been shown to be reliable,
but they still are expensive,” said Niemann. That’s why LFG Technologies
usually recommends reciprocating engines to generate power rather
than turbines. The capital cost is much lower and payback more
EPA’s Landfill Methane Outreach Program (LMOP) currently lists
only 509 operational projects generating 1,563 megawatts of electricity
and 304 million standard cubic feet of gas per day (MMSCFD).
They also list 530 landfill candidates with the potential to
produce 1,170 megawatts and 15.5 MMSCFD. There’s huge opportunity
for greater gas to energy projects. Private investment and development
companies are willing to front the capital costs to build systems
in return for the carbon credits and a share in the ongoing electric
production, even for small and medium sized landfills.
“Whether flaring it or combusting it in an engine to generate
electricity, you eliminates greenhouse gases. You change it into
other compounds that are different, but you eliminate volatile
organics from going into the air,” said Rogers.
The Law of Conversations of Mass states that for any chemical
process in a closed system, the mass of the reactants must equal
the mass of the products. It’s all going someplace anyway. There
is no perfect way to handle greenhouse gas emissions from landfills,
but as long as EPA regulations lead to flaring-off the methane,
landfills may as well productively use that energy to generate