Biomass can save the world or so we are told. The twin specters of
looming energy shortages emptying our wallets and global warming
melting glaciers make finding a solution for our petroleum addiction
urgent from both a financial and environmental perspective. However,
there is a cost to producing and converting biomass into fuels and
electricity.
Removing too much biomass can deplete nutrients from the soil and
possibly increase erosion. Landowners, farmers, loggers and other
people involved in the production and harvest of biomass need to be
compensated and the price of biomass needs to cover those costs.
Researchers from Minnesota and Wisconsin zeroed in on one particular
system—small trees and undergrowth in the Superior National
Forest—to gauge the environmental and economic costs of removing
biomass from the forest.
The study was conducted by Don Arnosti of the Institute for
Agriculture and Trade Policy, Dalia Abbas and Dean Current of the
University of Minnesota and Michael Demchik of the University of
Wisconsin, Stevens Point. “Is biomass harvesting sustainable?”
Arnosti says. “That’s a very simple question about a very complex
situation. I don’t think it has a simple answer. I guess the
simplest answer I could give is that under the right conditions and
with the right vision and moderation, the answer is yes. Would I
validate people who would say it might be unsustainable in certain
circumstances? That answer is also yes.”
The IATP studies policies on food, trade and sustainability. In
2005, it received a grant to look at the barriers for sustainably
harvesting biomass. The organization started looking at biomass
resources because it noticed that the region’s pulp and paper
industry had started to use more “dirty chips” for fuel. Dirty chips
are the result of grinding or chipping whole trees, forest or green
waste. They represent a readily available source of supply. However,
the chips are of random shapes and sizes which could lead to feeding
problems if using automated systems. This will also affect
combustion. The contaminants (bark, foliage, dirt and others) will
lead to higher ash content. Dirty chips are commonly referred to as
“hog fuel” by forest contractors and forest industry personnel.
Some boiler systems (particularly at the larger scale) are designed
to burn this type of chip. When using dirty chips it is important to
match the boiler system with the supply.
“Back in 2005 biomass was not a hot topic, it became so with higher
energy prices,” Arnosti says. “We really got involved in this study
because we wanted answers. We wanted to understand the economic
barriers that were controlling the industry and the ecological
boundaries of sustainability.”
Fire Prevention and Biomass Collection
The study looked at nine areas being cleared for fuel reduction to
prevent forest fires. The material being removed was a mix of balsam
fir that had been killed by spruce budworms and aspen in areas where
understory balsam firs created ladder fuels that cause devastating
crown fires in areas of taller 60- to 80-year-old red and white
pines. The treatments varied by site but generally called for the
removal of trees and brush smaller than a diameter of 5 or 6 inches
at a point 4 feet above the ground. “We partnered with the [U.S.]
Forest Service because they were already making fuel management a
high priority, especially near urban areas,” Arnosti says. “It turns
out that the Superior National Forest has a lot of development like
that embedded in the forest. They were developing plans to reduce
fuels and were eager to understand how biomass markets and harvest
could factor into what, up until then, had been a cut, pile and burn
fuel reduction.”
Arnosti says the researchers started out looking for the answer to
two questions and quickly found they needed a third answered. They
wanted to find out what equipment and techniques a logger would need
to efficiently harvest biomass in the forest. The second question
was what the ecological impacts of the harvest were. “The third
piece that we kind of stumbled into was the administrative
complexity—the land management mindset,” he says. “All of the
procedures were set up with high-value timber in mind while biomass
is a low-value product that probably will have to be harvested below
cost. You can’t have loggers bidding to get [the Forest Service] the
highest return on the contract when you are doing biomass and really
subsidizing the removal.”
The main conclusion of the study was that there are many ways to
interrupt a smooth supply of biomass to a market. “I’m not going to
say there is only one way to get it right, but there are probably 14
different ways you can screw it up,” Arnosti says. The potential
problems fall into the three broad categories captured by the
researcher’s questions. “One, the administrators need to have
procedures and practices in place that facilitate biomass
harvesting,” he says. “Two, the contractors or loggers need to have
training or experience in utilizing their equipment to harvest
high-volume, low-value material. Finally, biomass markets have been
developed with the assumption that the biomass material is going to
be free or at a very low cost. That may be true if you are just
picking up tops and branches at a timber harvest site, but if you
want to get beyond the boom and bust volumes that come with the
timber market, you need to recognize that pricing has to be greater
than zero.”
Loggers Adapt
Another aspect of the study was trying to capture the logger’s
voice, as the study titled one of its chapters. There is a large
body of academic literature on removing biomass for energy or forest
management, but very little of it comes from the perspective of the
operators who actually do the work of cutting the trees and moving
them out of the forest. “We found that in many instances existing
equipment could be adapted to biomass harvesting,” Arnosti says.
“But operating training and experience greatly increased
productivity. For example, a particular logger that worked on a
number of our tests figured out on his own how to carry two or three
times as much biomass in a forwarder as he did at the beginning of
the project. He figured it out and it was very different than the
techniques he used to forward round wood.” A forwarder is a piece of
equipment used to move wood from the cutting area to the collection
area.
Abbas did most of the formal interviews with the loggers. She says
one of the most profound differences for the loggers is that they
had to walk every area before they would bid on clearing and
collecting the biomass. Usually experienced loggers, who have worked
a particular region, are familiar enough with the costs and paybacks
of gathering round wood that they can calculate the expected costs
and paybacks just from looking at a map of a timber offering.
Gathering biomass was so different for them that they needed to walk
the land to understand the pitfalls they would be facing. “It was
normal for them to go into an area and extract a larger tree from
the site,” she says. “But this was the first time they would enter a
site solely to remove the smaller material.”
Arnosti described logging work as something so familiar to the
workers they could do it on “semi-autopilot” which allowed them to
become very skilled at what they did. Abbas found that one of the
skills that made loggers so efficient was that they knew how to fell
trees and position them so that the workers moving the trees out of
the woods could do so with the least amount of wasted time and
effort. For biomass harvesting, the loggers had to relearn these
skills. “It was important that operators communicated with each
other on the site,” Abbas says. “For example, they learned which
machine would follow the next. So the operator would cut the
material to be forwarded in a way, even though it would have taken
him longer, that made the entire operation more efficient. But if
you get a divided operation, where someone is responsible for
cutting the material without thinking of the best way to lay it out,
then you get a lot of hours of harvesting and that isn’t a very
practical option for the loggers.”
At current prices, Arnosti says biomass cannot pay its way out of
the woods. Biomass is likely to remain an adjunct to fuel reduction,
habitat management or disease control operations and timber
harvests. “What I have concluded is that biomass, at least woody
biomass will likely forever be a coproduct,” he says. “It cannot be
seen as the single reason you are doing land management. In the case
of timber, the value of the wood will cover the cost of harvesting
it, moving it and delivering it to a market at a profit. Even with
today’s high energy prices, and based on our analysis, even if
energy prices doubled again, we would find the costs of cutting,
processing, transporting and delivering biomass would exceed the
market value of that biomass.”
If the Forest Service wants to make biomass harvesting an integral
part of its forest management practices, it will have to be more
flexible in its regulations. As Arnosti points out, these
regulations were developed for high-value round wood timber
operations. There were times during the study when operations had to
be shut down because the wrong species or wrong size tree was
felled. “You can’t just follow the existing guidelines and assume it
is going to include biomass harvesting,” Abbas says. “They need to
be more practical and open with the loggers.”
Along with the ecological and logistical concerns about the
harvesting system, economic questions also had to be answered. If
biomass harvesting doesn’t pay for any of the players in the
economic chain, then the entire system breaks down. “If you are
talking about sustainability, then economics is one of the pieces
you have to look at,” Current says. “Right now, with the payments
from the Forest Service you can do this economically—in other cases,
maybe not.”
Because the material that was collected for the study was usually
just burned or bulldozed, there wasn’t much good economic data on
what it costs to collect and deliver it to processors. “I think we
are still learning how we can make these systems work,” Current
says. “One thing we took out of this is that there are many studies
that estimate the amount of biomass we can take out of state,
private and federal sources, but there is still the question of the
economic availability of that amount of biomass. That’s a question
we need to look at more closely.”
While some biomass energy business plans assume that there are
plentiful supplies of free or low-cost biomass, the owners of that
biomass will expect to be paid for it. In some cases, biomass will
be cheap because the alternative is paying the high cost to dispose
of it in landfills or incinerators. However, that scenario will not
be universal. “There are some loggers who are doing this collection
now, but there is going to be a price threshold for that,” Current
says.
