Geography Reference
In-Depth Information
locales substantial real estate has been devoted to
wind farms
that are testing and applying large-scale
feasibility of this energy type. Regardless of their success, these “farms” clearly represent a new ad-
dition to the cultural landscape (Figure 16-5).
Figure 16-5:
Wind farms such
as this one may
become more
common-place
as fossil fuels be-
come depleted.
Geothermal energy
In the opinion of some, we are virtually standing on top of all the energy we will ever need. That is
a reference to the very high temperatures that exist within the Earth's crust (see Chapter 6). Because
this heat literally radiates from the Earth, scientists refer to it as
geothermal energy
.
Theoretically, all that is needed is to drill down to the level of very hot rock, inject water, and extract
theresulting steam. Thismaybeuseddirectly toprovidehomeheating andhotwater.Underpressure,
steam is also a physical force (witness the tiny whistling steam jet on your tea kettle, only imagine a
huge one) that can be used to turn a turbine (propeller) that operates an electrical generator.
Geothermal energy is free and non-polluting. But a major impediment stands in the way of its wide-
spread use — cost. In most places suitably hot rock is encountered about 2 to 3 miles beneath Earth's
surface. Drilling and operating steam-producing wells that deep would not be cost competitive with
standard coal-fired plants. Some locations are exceptions, however. In lands near plate boundaries,
the attendant fissures make it possible for interior heat to come close enough to the surface to allow
for economical human exploitation. In Iceland, for example, nearly all home heating and hot water
comesfromgeothermalenergy.InpartsofNorthernCalifornia(andafewotherlocationsworldwide),
electricity is produced in this manner. In the future, geothermal energy may become generally avail-
able as a result of technological progress and the changing economics of energy production. For now
however, its viability is governed largely by the geography of plate boundaries.
