Environmental Engineering Reference
In-Depth Information
RENEWABLE ENERGY
B
enefits
•
Wind, sun, ocean, and geothermal energy are available in abundant quanti-
ties and are free to use.
•
Renewable sources have low carbon emissions; therefore, they are consid-
ered to be environmentally friendly.
•
Renewable energy helps stimulate the economy and create job opportunities.
•
Renewable energy sources enable the country to become energy indepen-
dent, not having to rely on foreign (often hostile) sources.
n
on
-B
enefits
•
Initial set-up costs of renewable energy sources are quite high.
•
Solar energy is limited to daytime availability and cannot be obtained dur-
ing the night or a rainy season.
•
Geothermal energy can bring toxic chemicals from beneath the surface of
the earth up to the top and can cause environmental damage.
•
Hydroelectric dams are expensive to build and can affect natural flow and
wildlife.
•
Wind energy production requires high winds and must be sited properly
to be effective. Also, wind turbines are tall structures that can affect bird
populations.
ENERGY USE IN THE UNITED STATES
Use of energy in the United States is shared by four major sectors of the economy. Each
end-use sector consumes electricity produced by the electric power sector (EIA, 2013):
•
Commercial
—18% (buildings such as offices, malls, stores, schools, hospi-
tals, hotels, warehouses, restaurants, places of worship, and more)
•
Industrial
—32% (facilities and equipment used for manufacturing, agricul-
ture, mining, and construction)
•
Residential
—21% (homes and apartments)
•
Transportation
—28% (vehicles that transport people or goods, such as
cars, trucks, buses, motorcycles, trains, subways, aircraft, boats, barges,
and even hot-air balloons)
Primary energy consumption in the United States was almost three times greater in
2012 than in 1949. In all but 18 of the years between 1949 and 2012, primary energy
consumption increased over the previous year.
The year 2009 provided a sharp contrast to the historical trend, in part due to the
economic recession. Real gross domestic product (GDP) fell 2% compared to 2008,
and energy consumption declined by nearly 5%, the largest single year decline since
1949. Decreases occurred in all four of the major end-use sectors: commercial (3%),
industrial (9%), residential (3%), and transportation (3%) (EIA, 2013).
