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发帖数: 11530 | 1 Time to Think Hydropower
The nation's waterways could provide much more clean energy
By Linda Church Ciocci | April 9, 2009 | 30
hoover dam Hoover Dam, also sometimes known as Boulder Dam, is a concrete
arch-gravity dam in the Black Canyon of the Colorado River, on the border
between the U.S. states of Arizona and Nevada. Image: Tobi 87
Imagine what our economy would be like if almost half of our electricity
came from renewable energy resources. No fuel price shocks, no foreign
control, no worries about climate change—just clean, abundant, affordable
electricity.
Before World War II, Americans actually lived that way, thanks to hydropower
. The massive public works projects undertaken during the Great Depression
built a fleet of huge facilities on some of the country’s biggest waterways
. Job creation, electrification and inexpensive power modernized the rural
South and helped to industrialize the West.
Then, the story goes, after the war ended and the atomic age began,
hydropower growth slowed to a trickle. A myth that hydropower couldn’t
expand any further gained currency. Well, get ready for some myth-busting.
Hydropower is the largest renewable resource in the U.S., providing about 8
percent of the nation’s electricity. Analysts say that capacity can double
in 30 years, rivaling the growth predicted for the nuclear power industry
and at a fraction of the cost. The Federal Energy Regulatory Commission is
reviewing more than 30,000 megawatts’ worth of new projects, equal to a
third of all existing hydropower capacity and big enough to power the New
York metropolitan area.
Surprised? Many people are, because they still think of hydropower only on a
scale of the giant Hoover Dam. The fact is, new technologies are creating
ways to generate electricity in all kinds of waterways. For example,
turbines that rotate slowly like underwater windmills can sit in rivers,
aqueducts or other locations where water flows freely. Other units in oceans
or tidal waters generate electricity as they bob up and down.
Even existing dams hold promise for energy production. Only about 3 percent
of the country’s 80,000 dams generate electricity. Power-generating
turbines could be added to many of these structures. The hydropower industry
is encouraging the federal government, which owns many of these nonpowered
dams, to begin assessing the potential.
Beyond that, engineers are finding ways to generate more electricity at
existing hydroelectric dams by installing more efficient turbines and other
technologies. The Grant County (Washington State) Public Utility District is
almost halfway through a project to replace 10 turbines at its Wanapum Dam
that will increase the facility’s capacity by more than 10 percent. The new
turbines, developed through a public-private partnership, also offer a more
“fish friendly” design.
Projects such as this one that maximize efficiency and reduce environmental
impact are starting to attract support from environmentalists, who
appreciate hydropower’s ability to provide reliable, affordable energy
resources without greenhouse gas emissions.
The U.S. hydropower industry is pleased to see the Obama administration take
a closer look, and we’re urging officials to invest in federal research
and development that can propel new water power technologies to market. As
the administration examines public works projects that can jump-start the
economy, it should consider hydropower initiatives, just as its predecessors
turned to hydro development during tough economic times 75 years ago.
The industry is also asking Congress to ensure that such development
receives the same tax incentives given to other renewables. Hydropower
should be part of state and federal policies, too. From renewable portfolio
standards to comprehensive energy and climate strategies, hydropower offers
a proved resource.
(excerpt)
Full article available to subscribers:
http://www.scientificamerican.com/article.cfm?id=time-to-think- |
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