on Technology –
By Rod Siring
Vigilante Electric Cooperative, Inc.
Reprinted with permission.
Last month's spotlight on technology discussed distributive
generation, in particular, electrical generation through the
advancements of fuel cells and micro-turbines. Much time and money
has been put into the technologies that will light our future, and
as important as this is, we may be putting the cart before the
horse. These technologies are being advanced to meet future needs
because most existing methods have a negative impact on our
environment. The arguments are hydro damages fish habitat, coal
fired plants emit unhealthy substances into the air, and nuclear
is too dangerous. Looking at these arguments, is the problem the
way we generate or is it the sources of generation? With water
being protected, pollution concerns of coal, and the rising costs
and limited known reserves of fossil fuels, other sources of
energy need to be developed. This is where research into biomass
generation comes in.
Biomass, simply put, is organic matter. It begins as energy
from the sun, which is stored in plants through photosynthesis.
Biomass utilizes the energy content of such items as agricultural
residues (e.g., bagasse from sugarcane, corn fiber, rice straw and
hulls, wheat straw and nutshells); wood waste (e.g., sawdust,
timber slash and mill scrap), paper trash and yard clippings in
municipal waste; and energy crops (fast-growing trees like poplar
and willow); and grasses, like switchgrass, elephant grass, and
prairie bluestem). Plus it utilizes the energy available in the
methane captured from landfills, municipal wastewater treatment
plants, and manure lagoons on cattle, poultry and hog farms.
Direct combustion is the simplest and most common method of
capturing the energy contained within biomass. The technology for
this process is very similar to that used for coal. In fact,
biomass and coal can be handled and bum in essentially the same
fashion. Direct combustion of the fuel heats water to create
steam. The steam turns the rotor of a turbine to produce
electricity. Since coal is fossilized biomass the two can be burnt
together in "co-fired" applications. One significant
difference between the two is that other elements have been added
to the fossilized biomass, things like sulfur and mercury that
when bum are released into our atmosphere.
Gasification is the newest method to generate electricity from
biomass. Instead of simply burning the fuel, gasification captures
about 65 percent to 70 percent of the energy in solid fuel
converting it first into combustible gases. This gas is then
burned in the same fashion that natural gas and propane are burned
to create electricity.
The potential for biomass generation is tremendous. The United
States has the land and the agricultural infrastructure available
to produce enormous quantities of biomass in a sustainable way.
The potential is there to replace half of the nation’s gasoline
usage or all of the nation's nuclear power without a major impact
on food prices. Shifting part of the $50 billion now spent for oil
imports and other petroleum products to rural America would have a
profoundly positive effect on the economy, in terms of jobs and
industrial growth. The Department of Agriculture has estimated
that 17,000 jobs are created for every billion gallons of ethanol
produced, and the Electric Power Research Institute has estimated
that producing 5 quadrillion BTU's of electricity on 50 million
acres of land would increase overall farm income by $12 million
dollars annually. The U.S. consumes 90 quadrillion BTU's annually.
Biomass is probably the most underutilized renewable energy
source in the U.S. today. Biomass currently provides about 4
percent of the energy produced in the U.S. and it could easily
supply 20 percent. Its environmental impact is negligible, and its
use can actually benefit the environment when the methane from
sewage and landfill is collected and process. There are huge
economic benefits to the agriculture, and wood products
industries, both of which are vital in Montana. There is not much
of a downside to the development of biomass generation, and with
oil and gas prices high, and the cost of natural gas doubling in
the past year, biomass generation and gasification becomes viable.
The critically needed next steps are continued technical progress
in conversion efficiency and construction of a series of
integrated demonstration facilities that will give the people
working in agriculture, wood products and the investors the
confidence to build this new American industry.