Environmental Engineering Reference
In-Depth Information
FIGURE 8.1
Solar shingles are installed on a rooftop.
naturally as a gas. It is always combined with other elements, such as with
oxygen to make water. Once separated from another element, hydrogen can
be burned as a fuel or can be converted into electricity.
Not all renewable energy resources come from the sun. Geothermal energy
taps the Earth's internal heat for a variety of uses, including electric power pro-
duction and the heating and cooling of buildings. And the energy of the ocean's
tides come from the gravitational pull of the moon and the sun upon the Earth.
8.4.1 Ocean and Alternative Energies
In fact, ocean energy comes from a number of sources. In addition to tidal
energy, there is the energy of the ocean's waves, which are driven by tides
and winds. The sun also warms the surface of the ocean more than the
ocean depths, creating a temperature difference that can be used as an
energy source. All these forms of ocean energy can be used to produce
e le c t r ic it y.
Why Is Renewable Energy Important?
Renewable energy technology content for this section provided in part
by the National Renewable Energy Laboratory and the Department of
E n e r g y.
Cost-effective energy efficiency programmes have been delivered by large
and small utilities and third-party programme administrators in some
parts of the country since the late 1980s. The rationale for utility invest-
ment in efficiency programming is that within certain existing markets for
energy-efficient products and services, there are barriers that can be over-
come to ensure that customers from all sectors of the economy choose more
energy-efficient products and practices. Successful programmes have devel-
oped strategies to overcome these barriers, in many cases partnering with
industry and voluntary national and regional programmes so that efficiency
