Environmental Engineering Reference
In-Depth Information
THE SECRET TO ENERGY SUCCESS: NATURALLY CONCENTRATED, STORED,
PLENTIFUL ENERGY
One lesson of the failure of renewables is that
renewable
is not a useful criterion for a good energy source.
It says only that one of the inputs is derived from the sun; it says nothing about how long the other in-
puts will last, and, most important, it says nothing about whether the technology can generate energy that
is cheap, plentiful, and reliable. There's no reason to aspire to use an energy technology that we will use
forever. The real question is: For the relevant time horizon, what's the most efficient combination of ele-
ments that we can transform efficiently into the kind of energy we need in a way that is cheap, plentiful,
and reliable?
And so far in history, there has been one necessary ingredient to that: instead of spending huge amounts
of resources concentrating and storing a dilute and intermittent source, working with a source that nature
has already concentrated and stored for us—such as water (hydropower), the forces holding an atom to-
gether (nuclear power), or the powerful chemical bonds of the copious amounts of ancient, dead plants
lying around from previous eons (fossil fuels).
It is their preconcentrated, prestored, plentiful energy content that has made fossil fuels—and to a much
less but still important extent hydroelectric power and nuclear power—cheap, plentiful, reliable energy
sources.
HYDRO TECHNOLOGY: CHEAP, RELIABLE, MEDIUM-SCALE ENERGY
If you've ever been in a rapidly flowing river, you can
feel
the energy stored in the moving water. Hydro-
electric energy technology transforms some of the power of that flowing water into usable, cheap, reliable
electricity using a turbine—much like a wind turbine, except driven by a far more powerful and reliable
force. Often a dam is used to store water near the source of a river and precisely control the downward
flow.
Historically, hydropower has faced two types of limitations that have prevented it from producing much
more than 6 percent of the world's power.
26
One category is natural limitations; the other is political limit-
ations.
The main limitation of hydroelectric power is there aren't nearly enough suitable water sites for it to be
a global source of energy. In China and Brazil, the top two consumers of hydropower, you can get a lot
of electricity from it; in Nebraska, you can't.
27
The United States has maintained a fairly constant hydro-
power consumption because we've run out of rivers to dam (which is unfortunate, because hydropower
lasts for decades; the Hoover Dam was built in the 1930s).
But there is considerably more opportunity to develop hydro around the world. Based on the number
of dammable rivers left, the International Energy Agency estimates that hydroelectricity has the technical
potential to grow by 92 percent in Africa and 80 percent in Asia.
28
Worldwide, according to an estimate
by the International Energy Agency, hydro has the technical potential to produce twice as much energy as
it does today; it is currently around 6 percent of global production.
29
That is an exciting prospect . . . but
not for most prominent environmental groups, whom you might think would welcome a four times greater
supply of cheap, reliable, non- CO
2
-emitting hydroelectric energy.
