Page 625 - Environment: The Science Behind the Stories

only in certain areas, and this water may be exhausted if it Explain hydrogen fuel cells and weigh options for
is overpumped. (pp. 616–617) energy storage and transportation
• Enhanced geothermal systems allow us to gain geothermal • Hydrogen can serve as a fuel to store and transport
energy from more regions, but the approach can trigger energy, so that electricity generated by renewable
earthquakes. (p. 617) sources can be made portable and used to power vehi-
cles. (pp. 620–621)
• Ground-source heat pumps heat and cool homes and busi-
nesses by circulating water whose temperature is moder- • Hydrogen can be produced cleanly through electrolysis,
ated underground. (p. 618) but also by use of fossil fuels—in which case its environ-
mental benefits are reduced. (p. 621)
Describe ocean energy sources and how we can
harness them • Fuel cells create electricity by controlling an interaction
between hydrogen and oxygen, and they produce only
• Ocean energy sources include the motion of tides, waves, and water as a waste product. (pp. 620–622)
currents, and the thermal heat of ocean water. (pp. 618–620)
• Hydrogen infrastructure requires much more development,
• Ocean energy is perpetually renewable and holds much but hydrogen can be clean, safe, and efficient. Fuel cells are
promise, but technologies have seen limited development silent and nonpolluting, and they do not need recharging.
thus far. (pp. 618–620) (p. 622)

testing your Comprehension

1. In general, what has spurred the use of renewable energy 6. How do modern wind turbines generate electricity? How
and what are the benefits of its use in environmental and does wind speed affect the process? What factors affect
economic terms? What is the most prevalent form of where we place wind turbines?
renewable energy we use? 7. Describe several environmental and economic benefits of
2. What factors and concerns are causing renewable energy wind power. What are some drawbacks?
use to expand? Which two renewable sources are experi- 8. Define geothermal energy, and explain three main ways in
encing the most rapid growth? which it is obtained and used. Describe one sense in which
3. What is concentrated solar power? Explain how it works it is renewable and one sense in which it is not renewable.
in a large-scale facility. 9. Describe some of the possible ocean energy sources.
4. Define photoelectric effect. Explain how photovoltaic (PV) 10. How is hydrogen fuel produced? Is this a clean process?
cells function and are used. What factors determine the amount of pollutants hydro-
5. Describe several environmental and economic advantages gen production will emit?
of solar power. What are some disadvantages?

seeking solutions

1. Explain how Germany accelerated its development of Do you think such a shift will be good for our economy?
renewable energy by establishing a system of feed-in tar- Why or why not?
iffs. Do you think the United States should adopt a similar 4. Explain the circumstances under which using hydrogen
system? Why or why not? fuel could be helpful in moving toward a low-emission
2. For each source of renewable energy discussed in this future. If you could advise policymakers of Iceland,
chapter, what factors stand in the way of an expedient Germany, or the United States on hydrogen, what would
transition from fossil fuel use? What could be done in you tell them?
each case to ease a shift to these renewable sources? 5. tHINK It tHRoUGH You have just graduated from col-
3. Do you think we can develop renewable energy resources lege, gotten married, landed a good job, and purchased
to replace fossil fuels without significant social, eco- your first home. You and your spouse plan to stay in
nomic, and environmental disruption? What steps would this home for the foreseeable future and are consider-
we need to take? Will market forces alone suffice to bring ing installing flat plate solar collectors and/or PV panels
624 about this transition, or will we also need government? on your roof. What factors will you consider, and what

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