Ch 14 - Energy Resources

Answers to Review Questions and Critical Thinking Questions

Review Questions

1. Fossil fuels are coal, oil, and gas, which originated in the form of organic matter. They are considered stored solar energy because they represent the altered remains of living organisms, which ultimately were generated through capture of solar energy.
2. The rank of coal is determined by its carbon percentage and its heat value on combustion. Rank is important because it is related to the amount of energy stored per unit mass mined and because it is related to impurity content.
3. Methane hydrates are ice-like compounds composed of methane molecules surrounded by “cages” of frozen water. They may represent an important, relatively clean alternative to oil and gas.
4. The major impacts of oil and gas exploration and development include road building, exploratory drilling, supply line construction, production drilling, disposal of wastewater, accidental oil spills, and air pollution at refineries.
5. Nuclear fission is the splitting of atomic nuclei to release stored energy.
6. The major environmental concerns related to nuclear energy include impacts of uranium mining, nuclear waste disposal, and the threat of nuclear explosions.
7. Geothermal energy is energy from the Earth’s interior.
8. Groundwater at normal temperatures can be used as an energy source because heat pumps can use the temperature differences between normal groundwater and ambient air temperatures to extract or dispose of heat.
9. The major renewable energy resources include solar, hydrogen, water, wind, and biomass.
10. Environmental concerns associated with hydroelectric power include the trapping of nitrogen gas in water falling over dams, reservoir sediment trapping, displacement of people, loss of land, loss of wildlife, and adverse changes to downstream ecology and hydrology.
11. Sources of biomass fuel include wood, dung, forest products, agricultural products, and burnable urban waste. Environmental concerns include air pollution, production of ash, and its sustainability.
12. Cogeneration is the utilization of waste energy at power-generation and industrial facilities to generate electricity.
13. The major differences between hard and soft paths relate to reliance on fossil fuels and large generating facilities, environmental impacts, and the sustainability of energy resources.
14. Sustainable energy policy refers to finding useful energy sources that can be maintained and do not pollute the atmosphere, cause climatic perturbations, or present an unacceptable risk.

Critical Thinking Questions
1. An answer to this question will need to consider the history of oil use and its impact on economic and social development, as the issue of oil’s environmental impacts and the perception thereof is clearly dependent upon historical context. The student should address the history of oil use and the state of the world prior to widespread oil use compared with today, as well as the multitude of influences on value systems then and now.
2. An answer to this question must address the economics of various energy sources, including costs of conversion to renewable sources, as well as the social and political influences on energy policy.