Key Concepts

After completing this chapter, you will be able to:

1. Explain the heavy reliance of industrialized economies on non-renewable energy sources.
2. Outline five major sources of energy that are available for use in industrialized countries, and describe the potential roles of these in a sustainable economy.

Energy Use

It is critical for any economy to have ready access to relatively inexpensive and accessible sources of energy for commercial, industrial, and household purposes. The use of large amounts of energy is especially characteristic of developed countries, such as Canada. As has been examined previously, relatively wealthy, developed countries use much more energy (on a per-capita basis) than do poorer, less-developed countries.

Ever since people achieved a mastery of fire, they have used fuels for subsistence purposes, that is, to cook food and to keep warm. Initially, locally collected wood and other plant biomass were the fuels used for those purposes. Perhaps only one-million people were alive when fire was first domesticated, and their per-capita energy use was small. Consequently, biomass fuels were a renewable source of energy because the rate at which they were being harvested was much smaller than the rate at which new biomass was being produced by vegetation.

In modern times, however, the human population is enormously larger than it was when fire was first put to work. Moreover, many countries now have intensely industrialized economies in which per-capita energy usage is extremely high. The combination of population growth and increased per-capita energy use means that enormous amounts of energy are used in developed countries. The energy is needed to fuel industrial processes, to manufacture and run machines, to keep warm in winter and cool in summer, and to prepare food.

Most industrial energy supplies are based on the use of non-renewable resources, although certain renewable sources may also be important. For comprehensiveness, both non-renewable and renewable energy sources are discussed together in this section.

Sources of Energy

The world’s major sources of industrial energy are fossil fuels and nuclear fuels, both of which are non-renewable. Hydroelectric power, generated using the renewable energy of flowing water, is also important in some regions, including much of Canada. Relatively minor energy sources, often called “alternative sources”, include biomass fuels, geothermal heat, solar power, wind, and waves, all of which are potentially renewable.

Any of the above sources can be harnessed to drive a turbine, which spins an electrical generator that converts the kinetic energy of motion into electrical energy. Solar energy can also generate electricity more directly, through photovoltaic technology (see below). Electricity is one of the most important kinds of energy used in industrial societies, being widely distributed to industries and homes through a network of transmission lines. The following sections briefly describe how these various energy sources are used.

Image 13.4. Electricity generated by sing nuclear fuel or by burning coal, oil, or natural gas uses non-renewable sources of energy. This is an airphoto of the Bruce Nuclear Generating Station in Ontario, with Lake Huron in the background. Source: Chuck Szmurlo, Wikimedia Commons, http://commons.wikimedia.org/wiki/File:Bruce-Nuclear-Szmurlo.jpg

Fossil Fuels

Coal, natural gas, petroleum, and their refined products can be combusted in power plants, where the potential energy of the fuel is harnessed to generate electricity. Fossil fuels can also power machines directly, particularly in transportation, in which gasoline, diesel, liquefied natural gas, and other “portable” fuels are used in automobiles, trucks, airplanes, trains, and ships. Fossil fuels are also combusted in the furnaces of many homes and larger buildings to provide warmth during colder times of the year. The burning of fossil fuels has many environmental drawbacks, including emissions of greenhouse gases, sulphur dioxide, and other pollutants into the atmosphere.

Nuclear Fuels

Nuclear fuels contain unstable isotopes of the heavy elements uranium and plutonium (²³⁵U and ²³⁹Pu, respectively). These can decay through a process known as fission, which produces lighter elements while releasing 2-3 neutrons per nucleus and an enormous quantity of energy. The emitted neutrons may be absorbed by other atoms of ²³⁵U or ²³⁹Pu, causing them to also become unstable and undergo fission in a process known as a chain reaction. An uncontrolled chain reaction can result in a devastating nuclear explosion. In a nuclear reactor, however, the flux of neutrons is carefully regulated, which allows electricity to be produced safely and continuously.

Nuclear reactions are fundamentally different from chemical reactions, in which atoms recombine into different compounds without changing their internal structure. In nuclear fission, the atomic structure is fundamentally altered, and small amounts of matter are transformed into immense quantities of energy.

Most of the energy liberated by nuclear fission is released as heat. In a nuclear power plant, some of the heat is used to boil water. The resulting steam drives a turbine, which generates electricity. Most nuclear-fuelled power plants are huge commercial reactors that produce electricity for industrial and residential use in large urban areas (Image 13.4). Smaller reactors are sometimes used to power military ships and submarines, or for research. 235U is the fuel that is used in conventional nuclear reactors, such as the CANDU system developed and used in Canada. ²³⁵U is obtained from uranium ore, which is mined in various places in the world. (Canada is a major player in uranium mining, most of which is exported; see Table 13.2.) Uranium produced by refining ore typically consists of about 99.3% non-fissile ²³⁸U and only 0.7% 235U. Most commercial reactors require a fuel that has been further refined to enrich the ²³⁵U concentration to about 3%. However, the Canadian-designed CANDU reactors can use non-enriched uranium as fuel.

Various elements, most of which are also radioactive (such as radon gas), are produced during fission reactions. One of these, ²³⁹Pu, can also be used as a component of nuclear fuel in power plants. To obtain ²³⁹Pu for this purpose (or for use in manufacturing nuclear weapons), spent fuel from nuclear generating stations is reprocessed. Other trans-uranium elements and any remaining ²³⁵U (as well as non-fissile ²³⁸U) can also be recovered and be used to manufacture new fuel for reactors.

So-called fast-breeder reactors are designed to optimize the production of ²³⁹Pu (which occurs when an atom of ²³⁸U absorbs a neutron to produce ²³⁹U, which then forms ²³⁹Pu by the emission of two beta electrons). Although fast-breeder reactors have been demonstrated, they have not been commercially developed. Breeder reactors produce “new” nuclear fuel (by producing plutonium) and thereby help to optimize use of the uranium resource. However, there are limits to the process because the original quantity of ²³⁸U is eventually depleted. Therefore, both ²³⁵U and ²³⁹Pu should be considered to be non-renewable resources.

A number of important environmental problems are associated with nuclear power. These include the small but real possibility of a catastrophic accident such as a meltdown of the reactor core, which can result in the release of large amounts of radioactive material into the environment (as happened at the Chernobyl reactor in Ukraine in 1986). Nuclear reactions also produce extremely toxic, long-lived radioactive by-products (such as plutonium), which must be safely managed for very long periods of time (up to tens of thousands of years). Enormous quantities of these “high-level” wastes are stockpiled in Canada and in other countries that use nuclear power, but so far there are no permanent solutions to the problem of their long-term management. Another problem is the emission of toxic radon gas and radioactivity from “low-level” wastes associated with uranium mines, structural elements of nuclear power plants, and other sources.

Fusion is another kind of energy-producing nuclear reaction. This process occurs when light nuclei are forced to combine under conditions of extremely high temperature (millions of degrees) and pressure, resulting in an enormous release of energy. Fusion usually involves the combining of hydrogen isotopes. One common fusion reaction involves two protons (two hydrogen nuclei, ¹H) fusing to form a deuterium nucleus (composed of one proton and one neutron, ²H), while also emitting a beta electron and an extremely large amount of energy.

Fusion reactions occur naturally in the interior of the Sun and other stars, and they can also be initiated by exposing hydrogen to the enormous heat and pressure generated by a fission nuclear explosion, as occurs in a so-called hydrogen bomb. However, nuclear technologists have not yet designed a system that can control fusion reactions to the degree necessary to generate electricity in an economic system. If this technology is ever developed, it would be an enormous benefit to industrial society. It would mean that virtually unlimited supplies of hydrogen fuel for fusion reactors could be extracted from the oceans, which would essentially eliminate constraints on energy supply. So far, however, controlled fusion reactions remain the stuff of science fiction.

Hydroelectric Energy

Hydroelectric energy involves harnessing the kinetic energy of flowing water to drive a turbine that generates electricity. Because the energy of flowing water develops naturally through the hydrologic cycle, hydroelectricity is a renewable source of energy. There are two classes of technologies for the generation of hydroelectricity.

• Run-of-the-river hydroelectricity involves tapping the natural flow of a watercourse without developing a large up-river storage reservoir. Consequently, this electricity generation depends on the natural patterns of river flow and is highly seasonal.
• Reservoir-generated hydroelectricity involves the construction of a dam in a river to store a huge quantity of water in a lake-like waterbody. The reservoir accumulates part of the seasonal high flow so that the generation of electricity can occur relatively steadily throughout the year. Some enormous reservoirs have been developed by flooding extensive tracts of land that had previously been covered by forest and wetlands in various places in Canada, such as in British Columbia, Labrador, Manitoba, and Quebec.

Canada’s largest hydroelectric generating facilities are located Churchill Falls in Labrador with a capacity of 5,429 megawatts (MW), La Grande-2 in northern Quebec with 5,328 MW, G.M. Shrum in British Columbia with 2,730 MW, and La Grande 4 and 3 in Quebec, with 2,651 and 2,304 MW, respectively. All of these facilities have large reservoirs to store water. Although hydroelectric energy is renewable, important environmental impacts are associated with use of this technology. Changes in the amount and timing of water flow in rivers cause important ecological damages, as does the extensive flooding that occurs when a reservoir is developed (see Chapter 20).

Image 13.5. Hydroelectricity is a renewable source of energy. This facility taps part of the flow of the Niagara River to generate electricity. Source: B. Freedman.

Solar Energy

Solar energy is continuously available during the day, and it can be tapped in various ways as a renewable source of energy. For example, it is stored by plants as they grow, so that their biomass can be harvested and combusted to release its potential energy (see Biomass Energy, below).

Solar energy can also be trapped within a glass-enclosed space. This happens because glass is transparent to visible wavelengths of sunlight, but not to most of the infrared. This allows the use of passive solar or “greenhouse” designs to heat buildings. Solar energy can also be captured using black, highly absorptive surfaces to heat enclosed water or another fluid, which can then be distributed through piping to warm the interior of a building.

Solar energy can also be used to generate electricity using photovoltaic technology (solar cells), which converts electromagnetic energy directly into electricity. In another technology, large, extremely reflective parabolic mirrors are used to focus sunlight onto an enclosed volume that contains water or another fluid, which becomes heated and generates steam that is used to drive a turbine to generate electricity.

Geothermal Energy

Geothermal energy can be tapped in the very few places where magma occurs relatively close to the surface and heats ground water. The boiling-hot water can be piped to the surface, where its heat content is used to warm buildings or to generate electricity. In addition, the smaller energy content of slightly warmed geothermal water, which is present almost everywhere, can be accessed using heat-pump technology and used for space heating or to provide warm water for a manufacturing process. Geothermal energy is a renewable source as long as the supply of groundwater available to be heated within the ground is not depleted by excessive pumping.

Wind Energy

The kinetic energy of moving air masses, or wind energy, can be tapped and used in various ways. A sailboat uses wind energy to move through the water, a windmill may be used to power the lifting of groundwater for use at the surface, and wind turbines are designed to generate electricity. Extensive wind-farms, consisting of arrays of highly efficient wind-driven turbines, have been constructed to generate electricity in consistently windy places in many parts of the world. In 2014, Canada had an installed wind-farm capacity of 8,517 MW, of which 24 had a capacity of greater than 100 MW (Canadian Wind Energy Association, 2014). The largest wind-farms are Seigneurie de Beaupré (QC, 272 MW), Gros-Morne (QC, 212 MW), Amaranth (ON, 200 MW), and Wolfe Island (197 MW).

Image 13.6. Wind is increasingly being used as a source of commercial energy in Canada. These wind turbines are operating near Tilbury in southwestern Ontario. Source: B. Freedman.

Tidal Energy

Tidal cycles develop because of the gravitational attraction between Earth and the Moon. In a few coastal places, tidal energy, the kinetic energy of tidal flows, can be harnessed to drive turbines and generate electricity. The Bay of Fundy in eastern Canada has enormous tides, which can exceed 16 m at the head of the bay. A medium-scale (20 MW) tidal-power facility has been developed at Annapolis Royal in Nova Scotia. There is potential for much more tidal power development within the Bay of Fundy, and there are ongoing technological studies to install additional facilities at various places there. The new installations will use tidal-powered turbines that are laid on the bottom or suspended in the water column, which avoids the environmental damage associated with a dam.

Wave Energy

Waves on the ocean surface are another manifestation of kinetic energy. Wave energy can be harnessed using specially designed buoys that generate electricity as they bob up and down, although this technology has not yet been developed on a commercial scale.

Biomass Energy

The biomass of trees and other plants contains chemical potential energy. This biomass energy is actually solar energy that has been fixed through photosynthesis. Peat, mined from bogs, is a kind of sub-fossil biomass.

Like hydrocarbon fuels, biomass can be combusted to provide thermal energy for industrial purposes and to heat homes and larger buildings. Biomass can also be combusted in industrial-scale generating stations, usually to generate steam, which may be used to drive a turbine that generates electricity. Biomass can also be used to manufacture methanol, which can be used as a liquid fuel in vehicles and for other purposes.

If the ecosystems from which biomass is harvested are managed to allow post-harvest regeneration of the vegetation, this source of energy can be considered a renewable resource. Peat, however, is always mined faster than the slow rate at which it accumulates in bogs and other wetlands, so it is not a renewable source of biomass energy.

Energy Consumption

The consumption of energy varies greatly among countries, largely depending on differences in their population and degree of development and industrialization (Table 13.8). In general, the per-capita use of primary energy (this refers to fuels that are commercially traded, including renewables used to generate electricity) in less-developed countries is less than about 1 toe per person per year. However, in the less-developed countries there is a relatively larger use of non-commercial or “traditional” fuels for purposes of subsistence and local commerce, such as wood, charcoal, dried animal manure, and food-processing residues such as coconut shells and bagasse (a residue of sugar cane pressing). The use of traditional fuels is not reflected in the data of Table 13.8.

Countries that are developing rapidly are intermediate in their per-capita energy consumption, but their rates of energy use are increasing rapidly due to their industrialization. In Malaysia, for example, the national consumption of primary energy increased by 167% between 1993 and 2013, while in South Korea it increased by 118%, in China by 270%, in India by 189%, and in Brazil by 103% (by comparison, the growth was 17% in Canada and 11% in the U.S.; WRI, 2014). While the use of energy has grown in these and other rapidly developing countries, their reliance on traditional fuels has dropped. This happens because traditional fuels are relatively bulky, smoky, and less convenient to use than electricity or fossil fuels, particularly in the urban environments where people are living in increasingly large numbers. In addition, the supplies of wood, charcoal, and other traditional fuels have become severely depleted in most rapidly developing countries, particularly near urban areas.

Relatively developed countries have a high per-capita consumption of energy (Table 13.8). Their energy use is typically more than 3 toe/person and almost entirely involves electricity and fossil fuels. The world’s most energy-intensive economies, on a per-capita basis, are those of Canada and the United States (9.38 and 7.13 toe/person, respectively) , which have more than 40-50 times the per-capita usage of people living in the least-developed economies of the world.

Table 13.8. Consumption of Primary Energy in Selected Countries in 2013. Primary energy refers to fuels that are commercially traded, including renewables used to generate electricity. National energy consumption mostly reflects the size of the economy of a country and its population, while per-capita use allows for a comparison of the lifestyle-intensity of average people. Source: Data from BP (2014).

In terms of the total amounts of energy being used, the largest consumers are China (2,852 toe in 2013), the United States (2,266), and Russia (699 toe). Canada is a highly developed country, but because of moderately-sized population and economy, it uses considerably less energy in total, about 333 toe.

The use of commercial energy in Canada increased by 116% between 1965 and 1990, and by 33% between 1990 and 2013, while per-capita consumption increased by 54% and 4% during the same periods, respectively (Figure 13.2). The fact that per-capita energy use increased much less quickly than national consumption suggests that Canadians have become more efficient in their use of energy, especially during the more recent period. Smaller automobiles, improved gas economy of vehicles, better insulation of residences and commercial buildings, and the use of more efficient industrial processes have all contributed to this increased efficiency. Nevertheless, although these gains of energy efficiency have been substantial, they have been more than offset by growth in the per-capita ownership of automobiles, consumer electronics, and other energy-demanding products and technologies. Also important have been large increases in industrial energy use associated with oil-sands developments in Alberta during the past several decades. These latter changes have caused the overall use of energy in Canada to increase substantially.

Figure 13.2. Trends in the Consumption of Primary Energy in Canada. Note the different scales of national energy consumption (1018 J) and per capita consumption (1012 J/person). Sources: Data from British Petroleum (2013).

The intensive energy usage by Canadians reflects the high degree of industrialization of our national economy. Also significant is the relative affluence of average Canadians (compared to the global average). Wealth allows people to lead a relatively luxurious lifestyle, with ready access to energy-consuming amenities such as motor vehicles, home appliances, space heating, and air conditioning. Canada is also a large country, so there are relatively large expenditures of energy for travelling. In addition, the cold winter climate means that people use a great deal of energy to keep warm.

Energy Production

As was examined in Chapter 12, a sustainable enterprise cannot be supported primarily by the mining of non-renewable sources of energy or other resources. Therefore, a sustainable economy must be based on the use of renewable sources of energy.

However, most energy production in industrialized countries is based on non-renewable sources. Averaged across the relatively developed countries shown in Table 13.9, non-renewable fossil fuels and nuclear power account for 91% of the total use of energy. Renewable sources, such as hydroelectric, geothermal, solar, wind, and biomass fuels, account for only about 9%. With such a small reliance on non-renewable sources, it is clear that the major economies of the world are not close to having developed sustainable energy systems. Considering the rapid rate at which reserves of non-renewable energy resources are being depleted, one wonders how long the energy-intensive economies of developed nations can be maintained.

Table 13.9. Energy Consumption in Selected Countries in 2013. Data are in units of 106 tonnes of oil equivalent. Source: Data from British Petroleum (2014).

Of Canada’s total consumption of primary energy in 2013, 31% came from petroleum, 28% came from natural gas, 6% from coal, and 7% from nuclear energy (Figure 13.3). These non-renewable energy sources account for 72% of the total use of primary energy in Canada. Most of the remaining production comes from hydroelectricity (27%), which is renewable (although it can cause substantial environmental damage through flooding to create reservoirs, and can require large amounts of non-renewable resources for the construction of dams, transmission lines, and related infrastructure; see Chapter 20). Another 1.3% involves the use of other renewable sources of energy, such as wind and biomass. There are also, of course, environmental impacts of the harvesting of trees and other kinds of biomass for use as fuel (see Chapter 23).

Figure 13.3. Sources of Primary Energy in Canada. Overall, about 86% of commercial energy consumption is derived from non-renewable sources. The data are for 2006 and are in units of 106 tonnes of oil equivalent. Biomass includes both solid and liquid forms, and “other renewables” includes geothermal, solar, and wind. Source: Data from British Petroleum (2008)

Electricity produced by public or private utilities accounts for much of the energy used by industry, institutions, and residences in Canada. About 61% of the 615-million MW-hours of electricity produced in 2012 was generated from hydroelectric utilities, 22% from fossil-fuelled sources, and 15% by nuclear technology (Statistics Canada, 2013). Within the renewable sector, hydro accounted for 96% of the electricity production, wind for 3%, and others for 1%.

Conclusions

About 72% of the consumption of primary energy in Canada is based on non-renewable sources, as is 39% of the electricity generation. Because the reserves of all non-renewable resources are being depleted rapidly, both in Canada and around the world, the longer-term sustainability of the energy-intensive economies of developed countries, and the lifestyles of their citizens, is highly doubtful.

Questions for Review

1. What are the various non-renewable and renewable sources of energy available for use in industrialized countries? What are the future prospects for increasing the use of renewable sources?
2. What are the key sources of energy and materials that are ultimately based on sunlight? Which of these resources would you consider to be renewable, and which not?

Questions for Discussion

1. Outline the ways in which you use energy, both directly and indirectly. For each of your major uses, how could you decrease your energy consumption? How would a decrease in energy consumption affect your lifestyle?
2. Biomass, wind, and hydroelectricity are all examples of renewable sources of energy. Examine the energy-source distributions for several countries in Table 13.9 and discuss why they are not relying more on renewable sources of energy.
3. Make lists of the apparent benefits and risks associated with nuclear power. Focus on resource and environmental issues, such as the depletion of fossil fuels, emissions of greenhouse gases, and the long-term disposal of toxic and hazardous wastes.

Exploring Issues

1. A committee of the House of Commons is examining the sustainability of the Canadian economy. You are an environmental scientist, and the committee has asked you to advise them on improving the sustainability of the use of materials and energy. What would you tell them about the sustainability of present use? What improvements would you recommend?

References Cited and Further Reading

Alberta Energy. 2008. Alberta’s Oil Sands. https://web.archive.org/web/20160505003335/http://oilsands.alberta.ca/

British Petroleum (BP). 2014. Statistical Review of World Energy, 2014. https://web.archive.org/web/20141025054702/http://www.bp.com/en/global/corporate/about-bp/energy-economics/statistical-review-of-world-energy.html

Canadian Nuclear Association. 2005. Nuclear Energy. https://cna.ca/

Canadian Association of Petroleum Producers (CAPP). 2014. Statistics Handbook. http://www.capp.ca/library/statistics/handbook/Pages/default.aspx Accessed November, 2014.

Canadian Wind Energy Association. 2014. Installed Capacity. http://canwea.ca/wind-energy/installed-capacity/ Accessed November, 2014.

Natural Resources Canada (NRC). 2014a. Mineral Production of Canada, by Province and Territory. NRC, Ottawa, ON. http://sead.nrcan.gc.ca/prod-prod/ann-ann-eng.aspx

Natural Resources Canada (NRC). 2014b. About Coal. NRC, Ottawa, ON. http://www.nrcan.gc.ca/energy/coal/4277

Ripley, E.A., R.E. Redmann, and A.A. Crowder. 1996. Environmental Effects of Mining. St. Lucie Press, Delray Beach, FL.

Statistics Canada. 2013. Table 127-0007. Electric power generation, by class of electricity producer. Table 127-0007, Statistics Canada, Ottawa, ON. http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=1270007&&pattern=&stByVal=1&p1=1&p2=-1&tabMode=dataTable&csid=

Statistics Canada. 2014a. Gross domestic product (GDP) at basic prices, by North American Industry Classification System (NAICS), annual (dollars). Table 379-0029, CANSIM database. Statistics Canada, Ottawa, ON. http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=3790029&&pattern=&stByVal=1&p1=1&p2=1&tabMode=dataTable&csid=Accessed November, 2014.

Statistics Canada. 2014b. Report on Energy Supply and Demand in Canada, 2012 Preliminary. 57-003-X, Statistics Canada, Ottawa, ON. http://www.statcan.gc.ca/pub/57-003-x/57-003-x2014002-eng.pdf

Statistics Canada. 2014c. Supply and disposition of crude oil and equivalent, monthly (cubic metres). Table 126-0001, CANSIM database. http://www5.statcan.gc.ca/cansim/a26?lang=eng&retrLang=eng&id=1260001&paSer=&pattern=&stByVal=1&p1=1&p2=-1&tabMode=dataTable&csid= Accessed November, 2014.

Tietenberg, T. and L. Lewis. 2011. Environmental and Natural Resource Economics.9th ed.. Addison Wesley, Boston, MA.

United States Geological Service. 2014. Mineral Commodity Summaries 2014. http://minerals.usgs.gov/minerals/pubs/mcs/