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Flip a
switch and the light goes on. It’s something we take for granted – the
electricity that powers our lives in countless ways everyday. Where does it come from, and
what do California forests, urban wood and agricultural fields have to do with it? And why
should we care, anyway? We should care because our
future depends upon how well we understand our past. Twenty-five years ago, Americans were
enduring energy shortages and waiting in long lines just to fill their gas tanks. OPEC,
the Organization of Petroleum Exporting Countries, was a household word, because the U.S.
was at the mercy of foreign countries for the supply of crude oil so vital to our economy.
OPEC was embargoing its oil, and energy prices were spurting. America was caught
unprepared, and many suffered.
The 70’s: Green Power is
Born
In response to the
crisis, Congress in 1978 enacted the Public Utility Regulatory Policies Act (PURPA), in an
effort to diversify and strengthen domestic energy production. California, in turn,
instituted policies to aggressively implement PURPA and stimulate development of renewable
energy sources. In an environment of high inflation and scarce energy, experts in the late
1970’s projected that the price of crude oil would reach $100 a barrel by the mid
1980’s.
The 80’s: Biomass Power Emerges
Out of this background
emerged a brand new industry – biomass power. The first small plants began producing
electricity in 1982-3, and the wood-fired generation infrastructure rapidly expanded
throughout California during the 1980's.
Instead of burning
non-renewable fuels such as coal, petroleum and natural gas, biomass power plants combust
wood waste to generate electricity. In the early days, most biomass plants utilized
sawmill residues exclusively. But as more plants were constructed and the number of
operating sawmills declined, biomass facilities evolved to provide numerous other solid
waste disposal options to society. Forest thinnings, agricultural
byproducts, orchard removals, and urban wood
waste also are now being converted to electricity, reducing the risk of wildfire in the
forests, avoiding tons of open burning and conserving landfill space. The biomass industry
annually consumes 7 million tons of organic waste – equivalent to 25 percent of all
the waste deposited in California landfills each year.
Forests – Biological
Reservoirs of Renewable Energy
Petroleum in nothing
but plant material buried underground for a long, long time. California has millions of
acres of temperate forests, some of it as biologically productive as any forest land in
the world. Trees, which we have by the billions, can be thought of as tiny power plants,
which take solar energy and nutrients and store them in their bark, wood, and foliage.
Forests are managed
for a variety of reasons, including recreation, watershed protection, wood production, and wildlife. In many
settings these are compatible, and forest management seeks to enhance the
health and
productivity of the forest while providing the benefits we all enjoy.
But many western
forests are choked with trees, because natural regeneration has not been followed by the
periodic, low intensity wildfires that these plant communities evolved with. Meandering
wildfires once served to thin the forest, consuming excess vegetative fuel and enhancing
diversity. Reintroducing fire now into dense, unnatural thickets is risky and unwise.
First, fuel loading has to be reduced.
Thousands of forested
acres are thinned annually, to improve forest health, protect the largest
trees and reduce the risk of catastrophic
fire. Thinnings can be designed with site-specific goals in mind, such as retaining
unthinned buffers or dead trees ("snags") to enhance wildlife habitat. Providing
a responsible disposal option for excess forest vegetation while putting it to work
generating power, biomass has become an integral part of forest management in California.
Agricultural Residues -- Potential Air Pollution
In the Central and Southern Valleys (the Sacramento, San Joaquin, Coachella and Imperial
Valleys) of California, agricultural residues have traditionally been disposed of by
open-field burning. Crop residues open burned include orchard prunings and removals, rice
crop wastes, and others. This open burning is extremely inefficient and highly
polluting, especially fine particulate matter, a pollutant of extreme health
concern.
The evolution of the
biomass power industry in many of the rural agricultural areas of the state has resulted
in the lessening of open burning, because the power plants collect the ag residues, and
combust them in highly-controlled boilers, reducing the emission of air pollutants by over
95%. Many of the biomass plants have operating permit conditions requiring them to collect
certain amounts of agricultural wastes that would otherwise be open burned, assuring the
state of the reduction in air pollution.
Urban Wood Wastes - Landfill
Fillers and Greenhouse Gas Generators
Some of California's
biomass plants use what are termed "urban wood wastes" as fuel. These urban
wastes include furniture and other wood product manufacturing wastes, broken pallets and
trusses, construction project wood wastes, landscape and right-of-way trimmings, dunnage
and other wood wastes. Demolition wood wastes are not used because of the
potential hazards posed by
combustion of painted or otherwise-treated woods.
These urban wood
wastes have traditionally been disposed of in landfills, wasting their potential energy
and using up valuable landfill space. Further, the natural biodegradation of the woody
wastes in landfills generates methane, a potent greenhouse gas which may contribute to
global warming. Use of these woody wastes as biomass plant fuel eliminates the methane
generation, and preserves the landfill volume for other wastes which cannot be recycled or
reused.
The 90’s: Déjà vu All
Over Again?
The grim
oil price projections
from the era of the 1970's energy crisis have turned out to be very wrong. Although the
technology is reliable and has proven itself for many years, biomass power plants struggle
to survive in an era of deregulation and cheap power. Some have even shut down.
But history has a way
of repeating itself. We now import more foreign oil and natural gas than ever before, even
in the pre-energy crisis days of the early 1970’s. For now, biomass power is more
expensive than conventional fossil fueld power. But, as Wheelabrator’s Bill Carlson states,
"We’ve got this extremely elegant solution to a complex set of problems. Who
pays for clean air? Who pays for having less destructive wildfires?" |
