Module 9: Energy and Electricity

The Need For Energy Supply

Energy is a basic necessity for livelihood and economic and social development. Lack of power is directly correlated with poverty. "Human poverty is more than income poverty - it is the denial of choices and opportunities for living a tolerable life."(1) Access to energy is an important factor in reducing poverty and creating opportunity and sustainable development. Energy increases productivity and expands income-generating opportunities, enables reading and studying at home and in schools, facilitates domestic work and income-generation; reduces the burden of fuelwood collection, improves quality of healthcare; increases hours of clinic operation; facilitates vaccine cold-chain; decreases indoor pollution; and may reduce pressure on local biomass and carbon emissions. The 2006 report Energy Services for the Millennium Development Goals says that "without increased investment in the energy sector, the MDGs will not be achieved in the poorest countries."(2)

Traditional Forms of Energy and their Environmental Impact

Traditional electricity generation provides 18,000 terawatt-hours of energy a year, which is about 40% of humanity's total energy use. In doing so, it produces more than 10 gigatonnes of carbon dioxide every year, which is the largest sectoral contribution of humanity's fossil-fuel derived emissions. Petroleum use in lamps became prevalent in the early 19th century. The invention of the internal combustion engine and its use in automobiles and trucks greatly increased the demand for gasoline and diesel oil, both made from fossil fuels. Other forms of transportation such as railways and aircraft also required fossil fuels. Electricity and the petrochemical industry also rely on fossil fuel to generate electricity. Tar, a leftover of petroleum extraction, is used in construction of roads. While fossil fuels provide a large amount of energy, today they account for more than half of the global greenhouse gases pumped into the atmosphere annually. (3) All of the carbon in fossil fuels ends up in the atmosphere as carbon dioxide after combustion.(4), which contributes to global warming.(5)

Modern Sustainable and Renewable Forms of Energy

Renewable energy is harnessed from natural sources, and then replenished. These resources include solar energy, wind power, hydro power and geothermal energy. Climate change concerns, and the rising price of oil with the depletion of fossil fuel resources, are increasing renewable energy incentives.

Wind Power

Wind power is becoming increasingly popular, as it is readily available. Airflow can be used to run wind turbines; as wind speed increases, power output increases dramatically. On a global scale, the long-term technical potential of wind energy is believed to be forty times the current electricity demand. However, there are certain limitations to this energy form. Areas where winds are stronger and more constant such as offshore and high altitude sites are necessary to generate a significant amount of energy. Also, a large amount of land is needed for the wind turbines, which may be limited in certain areas. Overall, however, wind power is considered an excellent and powerful source of energy. It is renewable and produces no greenhouse gases, and it is growing at the rate of 30% annually, with widespread use in Europe, Asia and the United States.(6)

Hydropower

A significant amount of energy can be harnessed and utilized from running water. Even a slow flowing stream of water can yield a considerable amount of energy. Forms of water energy include:

Solar Energy

Solar energy is derived from solar radiation from the sun, and it is harnessed by photovoltaics. Solar technologies can be classified as active or passive depending on how they capture solar power. Active techniques include of photovoltaic panels and solar thermal collectors to harness energy. Passive techniques include orienting a building to the sun and selecting materials that absorb heat of light easily.(9)

Biofuel

Liquid biofuel includes bioalcohol such as bioethanol or oil such as biodiesel. Bioethanol is an alcohol made by fermenting the sugar components of plant materials and it is made mostly from sugar and starch crops. With advanced technology, cellulosic biomass, such as trees and grasses, are also used as stocks for ethanol production. Ethanol can be used as a fuel for vehicles in its pure form, but it is usually used as a gasoline additive to increase octane and improve vehicle emissions. Biodiesel is made from vegetable oils, animal fats or recycled greases.(10)

Geothermal Energy

This energy form is acquired by tapping the heat of the earth itself, both from kilometers deep into the Earth’s crust or from geothermal heat pumps at various locations around the globe. The earth's internal heat in the form of steam has a variety of uses, including electric power production, and the heating and cooling of buildings. Building power stations for these tasks are expensive, but operating costs are low. Dry, steam, flash, and binary plants are used to generate geothermal power. Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine. Geothermal energy from the core of the Earth is closer to the surface in some areas than in others. Hot underground steam or water tapping can be harnessed from areas such as Yellowstone basin in California, and Iceland.(11)(12)

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Footnotes

(1) “UNDP, Human Development Report 1997.” (New York: UNDP, 1997), 2.

(2) “Harvests of Development in Rural Africa: The Millennium Villages After Three Years.” (2003). Accessed 1 July 2010.

(3) Schiermeier, Q., Tollefson, J., Scully, T., Witze, A., and Morton, O. “ Energy alternatives: Electricity without carbon.” (13 August 2008). Nature. 454, 816-823. Accessed 29 July 2010.

(4) Tollefson, J. “Greenhouse-gas numbers up in the air.” (5 May 2010). Nature. 465, 18-19. Accessed 29 July 2010.

(5) “Fossil Fuels.” (25 July 2010). Wikipedia. Accessed 29 July 2010.

(6) "World Wind Energy Report 2009.” World Wind Energy Association. (February 2010). Accessed 10 July 2010.

(7) “Global Status Report 2006 Update.” Energy Information Administration international statistics database: Renewables. (2007). Accessed 8 July 2010.

(8) “Hydroelectric power - energy from falling water.” Accessed 8 July 2010.

(9) "Renewable Energy: How to Harness the Sun, Wind and Water. Natural Resources Canada's CanmetENERGY. Leadership in EcoInnovation." Natural Resources Canada. CanmetENERGY. Web.

(10) "Towards Sustainable Production and Use of Resources: Assessing Biofuels". United Nations Environment Programme. 2009-10-16.

(11) “Geothermal Energy: International Market Update.” Geothermal Energy Association. (May 2010). Accessed 9 July 2010.

(12) “Future of Geothermal Energy.” Geothermal Energy Association. (2006). Accessed 9 July 2010.