Biomass breakthrough
Nov 22 - St. Louis Post-Dispatch
The workhorse of renewable fuels in Missouri may be found in its
forests, farms and pastures.
Across the state, the idea of using plant waste such as wood scraps,
wheat straw or tree trimmings as fuel for electricity generation is
gaining steam.
In Perryville, a private developer is planning a $100 million plant that
will burn wood waste from nearby forests to generate enough electricity
to light 23,000 homes. The University of Missouri-Columbia is spending
more than $60 million to replace a boiler at its power plant that will
burn exclusively wood waste. Even the state's largest utility is looking
at how to use biomass at its power plants to displace some of its coal
usage.
A combination of new and proposed state and federal policies is driving
interest in renewable energy.
Among them is a ballot initiative approved by Missouri voters last fall
that requires investor-owned utilities to use renewable fuels, including
biomass, to generate 15 percent of their electricity by 2021.
Geography and the state's natural resources also play a part in the
emerging interest in biomass as a power plant fuel.
Missouri isn't considered a prime candidate for commercial-scale solar
projects. And wind farms have so far been limited to far northwestern
Missouri. Meanwhile, the state's forests, pasture and farmland could all
be considered potential fuel sources.
By one estimate, found in a June report by the Natural Resources Defense
Council, using just a fourth of the state's agricultural and wood waste
would equal 7 million tons of biomass per year -- enough to generate
about 10 percent of the state's power needs.
Biomass is generally defined as any kind of plant-derived organic
matter. The term often means wood waste such as mill residue from paper
or pulp mills; forest residue left behind by loggers; agricultural waste
such as corn cobs or any number of dense fast-growing crops such as
switchgrass that's planted specifically for use as fuel.
When used to generate electricity, biomass can be burned directly to
generate electricity or it can be mixed with coal, a process known as
co-firing.
Nationwide, biomass fuels less than 1 percent of the nation's
electricity. But that figure is expected to grow to 4.5 percent by 2030,
according to the Energy Information Administration, the statistical arm
of the Energy Department.
The use of biomass is generally embraced by environmentalists, who see
potential to displace coal and help cut emissions of carbon dioxide, the
main greenhouse gas linked to global warming.
Facilities that burn biomass emit only the CO2 that trees and plants
absorb while they're growing. But it's the same gas that would be
released when they die and decompose. Coal combustion releases CO2 that
was captured millions of years ago and wouldn't otherwise be vented into
the atmosphere.
The state's forest products industry also sees benefits from biomass by
creating a market for agricultural and wood waste that is often left in
the fields, forest floors or sent to landfills.
In the past, pulp and paper mills bought wood chips and similar
byproducts. But the mills have since left Missouri, so much of timber
that would have been used is instead left behind in the woods or isn't
harvested, said Brandon O'Neal, director of education and government
relations for the Missouri Forest Products Association, based in
Jefferson City.
"We have a lot of unused timber supply," O'Neal said. "You don't want to
go out and clear cut everything. But there is definitely a lot of timber
out there that can be harvested in a way that's healthy for the forest."
Compared with neighboring Illinois, Missouri is relatively rich in
forest-based biomass. Missouri could produce an estimated 2.9 million
dry tonnes of forest and mill residues annually, three times the volume
in Illinois, according to a 2005 report by the National Renewable Energy
Laboratory.
Farmers and private owners of forest land also stand to benefit under a
provision in the 2008 Farm Bill that provides matching payments for
feedstock that's sold to electric generators.
Advocates of the fledgling biomass industry say the emergence of a
market for wood chips and energy crops in Missouri could not only
displace fossil fuel use; it could improve the health of forests by
selectively thinning them of dead and diseased trees and replacing them
with healthy ones.
AmerenUE, which sells electricity to 1.2 million customers in Missouri,
sees the potential to displace 3 percent to 10 percent of the coal used
at some power stations with biomass, said Richard Wright, managing
executive for renewables.
The St. Louis-based utility has already had consultants Black & Veatch
study biomass opportunities, and it will probably conduct pilot projects
at certain plants within a couple of years, Wright said. But there's a
lot of analysis to be done before then.
"There are different barriers to being able to co-fire things other than
what (the plant) is designed to burn, such as coal," he said. "First you
have to decide what type of biomass is available. Then you have to look
at transportation. Then you go to the next step and evaluate the
facility and can your facility handle that fuel."
Making a biomass project cost-effective is another barrier. Right now, a
woody biomass is still more expensive on an energy equivalent basis than
coal, most of which is delivered from Wyoming's Powder River Basin,
Wright said.
AmerenUE investigated the potential for burning wood at its Sioux plant
in St. Charles County a few years ago after severe storms downed trees
and limbs across its service area, Wright said. But the plant's coal
crushing machine wouldn't take trimmings that were larger than a
quarter-inch in diameter. And tree trimmers couldn't mill the fallen
limbs and branches to the required size. In the end, executives scuttled
the idea.
The University of Missouri-Columbia is already meeting 10 percent of its
power plant fuel needs with biomass by co-firing wood waste with coal.
It's also replacing one of five coal boilers with one that exclusively
burns biomass. When the project is complete in late 2012, the university
will have reduced its coal purchases by about 15 percent, said Gregg
Coffin, the plant's superintendent.
Over the past few years, the university has experimented with various
types of feedstock, including corn cobs, storm debris, wood chips and
chopped up wooden pallets. In the future, the school could look to
dedicated energy crops grown in river bottoms that can't be developed or
used for farming.
By the time the boiler project is finished, the school will need 100,000
"green tons" of wood waste per year. By contrast the plant proposed for
Perryville would require almost 400,000 annual tons.
The university shouldn't have trouble finding enough biomass to meet its
needs, Coffin said. But he and other biomass advocates agree that
realizing the state's potential as a fuel supplier will take time.
Any power generator looking for a fuel supply will first look to the
cheapest and easiest source. In most cases that's waste from saw mills,
cabinet and flooring plants. But only about 3 percent of such mill
residue goes unused in Missouri, said Hank Stelzer, a state forestry
extension specialist and assistant professor at the University of
Missouri.
Of course, Missouri is flush with potential fuel sources: dense hardwood
forests, acres of farmland and miles of rolling prairie -- a seemingly
endless supply of biomass feedstock.
But logging companies working in Mark Twain National Forest lack the
expensive equipment needed to harvest forest residue. Much of the rest
of the state's 14 million-plus acres of forest land is divided among
350,000 or so private landowners -- potentially a logistical nightmare
for a plant developer trying to convince lenders that they have a
sustainable fuel supply.
Location is yet another challenge. Plants that burn biomass must be near
their fuel source because it's too expensive to transport thousands of
tons of wood chips more than 50 miles or so, depending on diesel prices.
They and others are concerned the biomass industry -- nudged by generous
incentives -- will develop too quickly and with too little forethought.
"If it's done in balance, it can be a good thing," Stelzer said. "The
problem we tend to have as humans is, we say, 'A little is good, so a
lot is going to be really great.'"
Greg Cancelada of the Post-Dispatch contributed to this report.
-----
To see more of the St. Louis Post-Dispatch, or to subscribe to the
newspaper, go to http://www.stltoday.com.
Copyright (c) 2009, St. Louis Post-Dispatch
Distributed by McClatchy-Tribune Information Services.
(c) 2009,
McClatchy-Tribune Information Services
|