New
Hydro Projects are Spawning
November
18, 2004 -- The tides are turning in favor of hydropower
production. While controversial, the worldwide efforts
are making waves right here in the United States.
Scientists at the Idaho National Engineering and Environmental
Laboratory say that the country could more than double
its supply of hydropower by accessing smaller streams
in addition to dams that are traditionally used for
such purposes. The next phase of hydropower, however,
will focus on smaller hydro units that are less disruptive
environmentally but still useful in supplying electricity
to remote areas.
According to the Idaho Falls-based research lab, about
170,000 megawatts of the clean and sustainable energy
form remain untapped and are not restricted from development
by the federal government. That's twice the hydro power
this country currently uses. Almost 60 percent of the
nation's water energy resources are potentially available
for development, it says, although less than 20 percent
of such resources have actually been harnessed. The
other 40 percent of water resources are located in areas
that are off limits to production, such as scenic rivers
and wilderness zones.
The study “showed the locations and concentrations
of resource sites everywhere in the country,”
says Doug Hall, project manager, in the Idaho lab's
newsletter. More than half of the nation's hydro potential
is in Alaska and the Pacific Northwest.
Distributed hydropower plants are analogous to windmills.
New hydropower technologies that include underwater
watermills do not require dams and could be applied
at a number of the potential sites, say the Idaho scientists.
The practical value of each site, though, is dependent
on stream flow, access to power lines and proximity
to markets. Meantime, building the infrastructure is
costly but over long periods, such investments pay off
because the cost of operations is low.
The United States has the fourth largest potential reservoir
of hydropower in the world. About 7 percent, or 80,000
megawatts, of this country's overall energy mix comes
from hydro sources, says the Department of Energy that
funded the Idaho lab study. Most of that power is highly
efficient, meaning that utilities are able to convert
lots of energy from it. Energy from streams, however,
is not necessarily efficient—but could still be
used by those who live in rural locations.
For at least the next half century, coal and natural
gas will make up the preponderance of fuels that produce
electricity—a portfolio that will most likely
grow to include more renewable and nuclear sources in
an effort to clean the environment. The U.S. Energy
Information Administration says that about 85 percent
of the energy consumed in the United States in 2000
was generated from coal, oil and natural gas while all
renewable energy forms and nuclear energy produced 7
and 8 percent, respectively.
Controversial Subjects
Like most power plants, hydro facilities are also a
divisive topic. To build dams that can generate lots
of electricity, local populations oftentimes have to
be dispersed and damages occur to the ecosystem. Such
projects can create huge lakes that harm sensitive streams
and rivers while the dams can reduce oxygen levels in
associated waterways. That limits the ability of migratory
fish to spawn.
“All
energy comes at a cost, and no energy source has had
a greater cost to our rivers than hydroelectric power,”
says Gerrit Jobsis, with the Costal Conservation League
in South Carolina. He spoke to U.S. lawmakers at a hearing
in Augusta, Ga., to express concerns about expanding
the use of hydro power along the Savannah River.
About 80 percent of the hydro facilities in South America,
for example, are located in rain forest. China, furthermore,
currently uses about a quarter of its potential hydropower.
By 2020, it expects to have tapped roughly 60 percent
of that potential. Toward that end, its Three Gorges
Project plans to construct 26 generators that produce
700 megawatts each along the Yangtze River by 2009—a
move estimated to dislocate 1.4 million people.
China will build four additional hydropower plants along
the Jinsha River, which will have a capacity of 38,500
megawatts. Meantime, it plants to build 13 other units
in the Yellow River that will produce nearly 8,000 megawatts
total. The multibillion dollar cost for all the plants
is necessary if China wants to avoid power shortages
and to diminish its reliance on coal that currently
supplies 67 percent of the electricity for the country.
At the same time, hydropower is the European Union's
leading renewable energy source. According to the German
sector association VDEW, it accounted for 9 percent,
or 277 billion kilowatt hours, of the overall output
in 2003. France was the EU's biggest hydro user. It
was followed by Sweden and Spain. Hydropower did account
for half the electricity generation in Austria and Latvia.
More than 100 countries are developing small hydro plants,
with the highest growth potential in the former Soviet
Union, South Asia and South America.
The big issue now, at least in the United States, is
the re-licensing of existing hydropower plants that
have long lives. The federal government issues such
licenses for 30-50 years and in 1993, more than 200
of those were up for renewal. That amounted to 2,000
megawatts of capacity. The pressure, no doubt, is forcing
dam owners to find more environmentally benign ways
of doing business such as improving the equipment at
small plants and increasing fish-friendly efforts at
large dams.
“The
damage to aquatic habitat from dams may be significant,
but acid rain, nitrogen deposition, and thermal pollution
from coal plants also lead to aquatic damage, as well
as to air pollution and global warming emissions,”
says the Union of Concerned Scientists. “Still,
if it's done right, small run-of-the-river hydropower
can be a sustainable and nonpolluting power source.”
Certainly, hydro plants are widely criticized for their
high costs both economically and environmentally. But,
a huge investment has been made in the nation's tributaries
to protect and restore habitat for fish species listed
under the Endangered Species Act. Most states with hydro
resources recognize the delicate balance and want to
assure both a stable flow of power and pristine surroundings.
Successful new models along with the demand to clean
the air and reduce global warming will spawn new hydro
projects.
by
Ken Silverstein
|
