Ralph E. Russo
Scientists classify energy sources as conventional or renewable. Conventional energy sources include fossil fuels: oil, natural gas, and coal. Renewable energy sources include apparently cleaner and harder-to-deplete energy sources: wind, solar, tidal, and geothermal. Figure 1 differentiates between conventional and renewable energy sources. The World Energy Report includes percentages of how each energy source contributes toward meeting world energy demands. These percentages are included in the table.
Figure 1.
Conventional vs. Renewable energy sources with percentages of the world’s energy demand that they meet.
Conventional
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Renewable
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Oil 36%
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hydropower 2.2%
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Natural Gas 21%
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biomass and combustible waste 2%
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Coal 23%
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geothermal *
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Nuclear 7%
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wind *
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*combine for around 0.5%
Solar*
3 Global Energy Supply Swiss Federal Office of Energy 2002
According to the World Energy Outlook Report (), fossil fuels were the predominant fuel used to meet world energy demand in the year 2000. In a Swiss Federal Office of Energy summary of the report, 80% of the world’s energy demand was described as being met from fossil fuel energy. Oil provided 36% of the global energy need. Coal use (23%) was slightly more than natural gas use (21%). Nuclear energy fueled 7% of the world’s demand. By comparison, renewable energy sources comprised a much smaller fraction of the energy needed to meet demand. Hydropower (2.2%) and non-commercial biomass (firewood, compost, and other combustible waste material) (2%) accounted for meeting less than 5% of the energy need. Geothermal, wind, and solar energy combined met only 0.5% of the energy demand. (World Energy Outlook Report ) 4
Oil met 60% of the transportation demand. Coal met 55% of the demand for producing electricity. Non-commercial biomass is not sustainable in the developed world but is more widespread in developing countries. (Global Energy Supply published by the (3) Swiss Federal Office of Energy.
http://www.energie-schweiz.ch/internet/00480/?lang=en
) 5
Considering these examples may lead one to appreciate the importance of the relationship between energy and society: a relationship perhaps now taken for granted. Although, with the price of gasoline now consistently about $2.00 a gallon for regular gasoline, many will certainly be thinking about the economic costs of driving. The purpose of their inclusion in this unit and the primary aim of the unit are to challenge the notion that energy can be taken for granted. Through understanding of how energy works and how countries have historically used energy, hopefully students will embrace the challenge of responsible energy development and use. A summary and explanation of objectives follows.