Biomass - Energy Policy Analysis: A Conceptual Framework - page 165

transporting, and processing biomass. If efficient cultivation and conversion processes are used,
the resulting emissions should be small, about 20 percent of the emissions created by fossil fuels
alone. And if the energy needed to produce and process biomass came from renewable sources
like wind, hydro, or solar energy, the net contribution to global warming would be zero (Brower
1992, 108). Similarly, if biomass wastes such as crop residues or municipal solid wastes are used
for energy production, there should be no net increase in greenhouse gas emissions. Biomass power
plants divert wood waste from landfills, which reduces the production and atmospheric release
of methane. There might even be a slight greenhouse benefit in some cases, because if wastes are
burned to produce electricity, some of the methane otherwise formed through anaerobic decay
of biomass in landfills would not be created, and methane is a more potent greenhouse gas than
carbon dioxide (Brower 1992, 108).
In sum, growing trees and other plants for energy might benefit soil quality and farm economies.
Energy crops could provide a steady supplemental income for farmers or allow them to work un-
used land without requiring much additional equipment. Moreover, energy crops could be used to
stabilize cropland or rangeland prone to erosion and flooding. Trees would be grown for several
years before being harvested, and their roots and leaf litter could help stabilize the soil. Perennial
grasses harvested like hay would minimize the need for disruptive tilling and planting; soil losses
with a crop such as switchgrass, for example, would be negligible compared to annual crops such
as corn, because it can be harvested for many years before replanting (Tyson 1990).
If improperly managed, however, energy farming could have harmful environmental impacts.
Although energy crops can be grown with less pesticide and fertilizer than conventional food
crops, large-scale energy farming could lead to increases in chemical use simply because more
land would be under cultivation. It could also reduce biodiversity through destruction of habitats,
especially if forests are more intensively managed than previously. If agricultural or forestry wastes
and residues are used for fuel, soils may be depleted of organic content and nutrients unless care
is taken to leave an appropriate portion of wastes behind on the land (Brower 1992, 109).
Dollar Costs of Utilizing Biomass
Unprocessed biomass typically cannot be cost-effectively shipped more than fifty to a hundred
miles by truck before it is converted into fuel or energy (UCS 2010). Consequently, all prices for
biopower and biofuels must be considered local, and there is substantial variation between locales.
The cost of energy produced from biomass depends on the type of biomass being utilized, the
type of energy being produced (heat, electricity, or fuel), the technology used, and the size of the
plant producing or using it.
In the United States, almost 57 billion kilowatt-hours of electricity were generated from bio-
mass, providing nearly 1.4 percent of total electric sales, in 2010 (USEIA 2011a, Table 8.2a). Us-
ing conventional combustion technology, the estimated cost to generate electricity from biomass
ranges from 5.2 to 6.7 cents per kilowatt-hour in Oregon and the Pacific Northwest, competitive
with other conventional fuels. Actual costs would vary depending on financing, location, system
design, and fuel cost. Power plants that burn biomass directly can generate electricity at a cost
of seven to nine cents per kilowatt-hour. In contrast, the estimated cost of generating electricity
from a new natural gas-fired, combined-cycle power plant is 2.8 cents per kilowatt-hour (NRDC
2011). In states such as Oregon, generating electricity from landfill gas is cost-competitive with
natural gas power generation. The estimated cost is 2.9 to 3.6 cents per kilowatt-hour (Oregon
Department of Energy 2007). Dollar costs in Oregon are roughly comparable to those in the rest
of the United States.