Environmental Engineering Reference
In-Depth Information
A majority of the plants in operation today (over 200 worldwide) are 20-30
years old and have a residual lifetime of only 10-20 more years. Uranium
ore is presently used to generate nearly 15% of the world's electricity (and
~20% of US electricity) and will likely last only a few more decades. Even
if more ore becomes available, nuclear energy can be an environmentally
high-risk technology as illustrated by the nuclear accidents in Russia's
Chernobyl plant in 1986 and Japan's Fukushima Daiichi power plant in
2011. The ecological devastation and the cost of cleanup of inevitable spills
of radioactive material are far greater and more complicated compared to
might be used in the future despite the safety risks they pose. Nuclear
waste disposal is another daunting problem. Nuclear plants are shut down
every 12-24 months to replace “spent” fuel with fresh uranium. The still
radioactive spent fuel has to be stored safely for thousands of years in
robust underground storage facilities (1000 ft deep site within in Yucca
for instance, has a half-life of 24,000 years!
1.1.2 Renewable Energy
The only route to sustainable development is via renewable energy
technolgies that are generally carbon-neutral. In the United States,
hydroelectric power is used to generate approximately 7.9% of the
electricity. A significant amount of our energy already comes from
renewable sources (19% of the energy used globally in 2011) primarily as
hydroelectric power. The new 22.5 GW plant at the Three Gorges Dam in
China is a remarkable example of the technology, which also illustrates
the socioeconomic costs of displacement of people and loss of land use
associated with such projects. Worldwide, however, the best hydroresources
are already exploited, and a natural limit to growth in hydroelectric power
generation might be anticipated. Yet, at this time, the highest growth rate
in electricity generation worldwide is with hydropower. In the United States
and in the West, the water resources are nearly fully tapped already and the
growth will be much slower.
1.1.2.1 Wind Energy
Wind energy that accounts for a respectable 2% of the worldwide electricity
generation (and ~1.2% of US energy) has the potential to grow and be
