|
OPEN QUESTIONS AND OVERLOOKED REALITIES
RENEWABLE ENERGY SOURCES
As a solid majority of survey respondents correctly answered, the renewable
technologies wind and solar power provide the smallest amount of America’s
energy of the options given.
As Table 1 shows, renewable energy technologies account for 6 percent
of U.S. primary energy consumption.
What is surprising about the relatively small role that renewable energies
play in our energy economy is the large measure of taxpayer dollars that they
have received. Since 1970, renewable technologies have received over $20 billion
in federal government subsidies to spur their development and market application.[33]
Despite this largesse, they have been unable to compete economically with far
cheaper and more reliable options such as coal and nuclear power. Of all renewable
technologies, wind and solar receive the most attention from the public, despite
their fairly dismal performance. Taken together, wind and solar today account
for just one-fifth of 1 percent of America’s annual energy consumption.
Advocates of these technologies generally make two arguments in their favor.
First, by harnessing the power and cycles of nature, they rely on fuels whose
supplies are seemingly inexhaustible (hence renewable), unlike finite resources
such as petroleum or coal. Second, renewables arguably have a less adverse impact
on the environment than traditional carbon-based energy sources. (Hydroelectric
power, however, has fallen out of favor with many environmentalists because
of the ecological side effects of damming rivers. Traditional proponents of
renewable energies, such as Greenpeace and the Natural Resources Defense Council,
tend to promote all renewable energy technologies except hydropower.) Non-hydro
renewables account for 3.35 percent of total U.S. energy consumption, or about
half of renewable energies’ total. The largest share of that small figure
is derived from energy from biomass, such as wood, waste, and alcohol fuels
like ethanol.
Given the expected jump in energy demand, it seems unlikely that renewables—particularly
such poor performers as wind and solar—will play more than a niche role.
The solar, wind, and geothermal industries would have to experience massive
growth over the next twenty-five years just to maintain their current small
share in our energy mix.
 The
disadvantages of renewables may best be understood by examining the punch that
they pack versus the space that they require. Wind turbines require huge tracts
of land to be set aside in order to generate meaningful amounts of power. To
generate the electricity that a typical 1,000-megawatt coal-fired or nuclear
power plant produces would require a utility-scale wind plant using 60,000 acres[34]
of land.[35] Similarly, it would take about 11,000 acres
of photovoltaic cells to generate the same amount from solar energy.[36]
Comparing fuel density provides an even better contrast. Biomass has far less
energy density than other fuels. Pound for pound, coal stores twice as much
energy as wood. On the same comparison, oil is twice as energy-dense as coal;
it packs the same amount of energy into half the weight and space. Nuclear power,
though, wins this test by a landslide. A single gram of uranium-235 packs the
same punch as four tons of coal or eight tons of wood.
Wind and solar energy, moreover, are not constant. The wind does not always
blow, and the sun does not always shine. Nuclear reactors, coal furnaces, and
gas-fired plants, on the other hand, can produce electricity virtually around
the clock, using far less space.
In certain instances, wind, solar, and other renewable energies can contribute
to the energy mix of a particular region or business. High-plains states like
Nebraska, Kansas, and Montana, with wide, flat spaces but sparse populations,
are good candidates for wind farms, whose turbines can exceed 100 meters in
height. The sun-drenched southwestern United States is a better candidate for
solar power than the rest of the continental U.S., where sunlight is more intermittent.
Still, it is unlikely that renewables can produce more than a tiny fraction
of the additional 1.774 trillion kilowatt-hours of energy that our economy will
require each year by 2030.[37]
|
