National biomass research conducted on all scales
Alternative energy sources are expected to play
a crucial role in helping the United States reduce its reliance
on imported petroleum and natural gas and in general, reduce the
burning of fossil fuels to generate electricity and provide fuel
The U.S. Department of Energy, along with many
partners, is helping to develop alternative fuel sources through
funding for research and developing legislation that will help
to create viable and commercial alternative energy sources.
Tom Welch, a DOE spokesman, believes that power
generated from biomass is a proven commercial electricity generation
option that the United States must pursue.
Question: To what extent is electricity generated
by biomass contributing to the nation’s energy supply?
Answer: With about 9,733 megawatts
(MW) of installed capacity in 2002, biomass is the single largest
source of non-hydro renewable electricity in the United States.
This includes about 5,886 MW of forest product and agricultural
residues, 3,308 MW of generating capacity from municipal solid
waste, and 539 MW of other capacity such as landfill gas.
Our studies show that the majority of electricity
production from biomass is used as base load power in the existing
electrical distribution system.
Question: In addition to pulp and paper facilities
using wood products and food processing plants that use waste material
to generate electricity, to what extent are other industries and
companies turning to biomass as an energy source?
Answer: More than 200 companies
outside the wood products and food industries generate biomass
power in the United States. Where power producers have access to
very low cost biomass supplies, using biomass in the fuel mix enhances
their competitiveness. This is particularly true in the near term
for power companies choosing to co-fire biomass with coal to save
fuel costs and earn emissions credits.
It is evident that an increasing number of power
marketers are starting to offer environmentally-friendly electricity,
including biomass power, in response to consumer demand and regulatory
requirements. This will only bolster and enhance that demand.
Many states, particularly California, are setting
benchmarks for biomass and other alternative fuel sources to generate
a percentage of their annual energy needs. We encourage these efforts
- be they state or municipally directed initiatives.
Question: What are the limits to biomass energy production
and what can be done to improve output?
Answer: There are four primary
classes of biomass power systems: direct-fired, co-fired, gasification,
and modular systems. Most of today’s biomass power plants are direct-fired
systems that are similar to most fossil fuel-fired power plants.
While steam generation technology is very dependable
and proven, its efficiency is limited. Biomass power boilers are
typically in the 20-50 MW range, compared to coal-fired plants
in the 100-1,500 MW range. The small capacity plants tend to be
lower in efficiency because of economic trade-offs. We find that
efficiency-enhancing equipment cannot pay for itself in small plants.
Although techniques exist to push biomass steam
generation efficiency over the 40 percent level, actual plant efficiencies
are in the low 20 percent range. Co-firing involves substituting
biomass for a portion of coal in an existing power plant furnace.
This is the most economic near-term option for introducing new
biomass power generation. Because much of the existing power plant
equipment can be used without major modifications, co-firing is
far less expensive than building a new biomass power plant.
Question: To what extent is biomass power helping
to reduce green house gases and other pollutants?
Answer: Compared to the coal
it replaces, biomass reduces sulfur dioxide (SO2), nitrogen oxides
(NOx), and other air emissions. After reconfiguring the boiler
for peak performance, there is little or no loss in efficiency
from adding biomass. This allows the energy in biomass to be converted
to electricity with the high efficiency (in the 33-37 percent range)
of a modern coal-fired power plant.
Biomass gasifiers operate by heating biomass
in an environment where the solid biomass breaks down to form a
flammable gas. This offers advantages over directly burning the
biomass. The biogas can be cleaned and filtered to remove problem
The gas can be used in more efficient power generation
systems - combined-cycles, which combine gas turbines and steam
turbines to produce electricity. The efficiency of these systems
can reach 60 percent. We anticipate that gasification systems will
be coupled with fuel cell systems for future applications.
Moreover, as the costs of fuel cells and biomass
gasifiers come down, we expect these systems will proliferate.
Modular systems employ some of the same technology
used in the other systems, but on a smaller scale more applicable
to villages, farms and small industry. These systems would be most
useful in remote areas.
Question: What is the Department of Energy doing to
promote research in alternative fuels?
Answer: We are a major provider
of funding for basic and applied research for converting biomass
to biofuels. Via our e-center, companies can register to submit
proposals and seek funding for their projects. We also conduct
joint solicitations with the U.S. Department of Agriculture as
part of the Biomass Research and Development Initiative. The primary
focus of the Biomass Program is to dramatically increase usage
by developing advanced technologies using cellulosic biomass instead
of grains, for more efficient power production or for catalytic
conversion to valuable products. Through the program, we foresee
biorefineries converting biomass into a variety of fuels, chemicals,
materials and power, much as petrochemical refineries do with oil
Question: The program has placed a focus on platform
technologies, in which biomass would be converted to base platform
chemicals to create a variety of products. How much progress is
being made on that front?
Answer: Sugar platform technology
breaks cellulose and hemicellulose (the bulk of most plant material)
down into their component sugars. Those sugars can be fermented
or otherwise converted to valuable fuels and chemicals, while thermochemical
platform technology transforms solid biomass to gas or liquid by
heating it with limited oxygen.
The intermediate synthesis gas or pyrolysis oil
can be more efficiently and cleanly combusted or converted to valuable
chemicals or materials. We are looking to industry to develop products
from sugars, lignin, synthesis gas, pyrolysis oils, and other intermediate
chemicals developed with these platform technologies.