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. Access to energy is an important factor in reducing poverty and creating opportunity and sustainable development. Electricity increases productivity and expands income-generating opportunities by enabling reading and studying at home and in schools, facilitating domestic work and income-generation, and reducing the burden of fuelwood collection. Electricity improves the quality of healthcare by increasing the hours of clinic operation and facilitating vaccine cold-chain supply. It also decreases indoor air pollution and may reduce pressure on local biomass and carbon emissions. The 2006 report Energy Services for the Millennium Development Goals noted that "without increased investment in the energy sector, the MDGs will not be achieved in the poorest countries." (1)

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. (2) All of the carbon in fossil fuels ends up in the atmosphere as carbon dioxide after combustion which contributes to global warming.(3)

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 and depletion of fossil fuel resources, are increasing interest in and utilization of renewable energy.

Wind Power

Wind power is becoming increasingly popular. 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. Overall, however, wind power is considered an excellent and powerful source of energy. Wind power is renewable and produces no greenhouse gases. The World Wind Energy Association estimates that, taken together, all wind turbines installed by end of 2017 produce can cover over 5% of the global electricity demand. (4) Wind power has become a central part of the strategies of many countries to phase out fossil and nuclear energy. For example, in 2017, Denmark set a new world record with wind power accounting for 43% of its total power. (5) Other countries, including Germany, Ireland, Portugal, Spain, Sweden, and Uruguay, have reached double-digit wind power share. , 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:

• Hydroelectric energy which includes hydroelectric dams

• Micro hydro systems that typically produce up to 100 kW of power using water rich areas as a remote-area power supply (RAPS)

• Damless hydrosystems that derive kinetic energy from rivers and oceans without using a dam

• Ocean energy includes technologies that harness energy from the ocean and sea, such as marine current power, ocean thermal conversion, and tidal power. (7),

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.(8)

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 to produce ethanol. 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. (9)

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 is 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. (10) Exploitable geothermal resources may be found throughout the world and are currently utilized in 83 countries.(11)

Footnotes

(1) The Earth Institute, Columbia University, & Millennium Promise. “Harvests of Development in Rural Africa: The Millennium Villages After Three Years.” (2003). https://bit.ly/2Kp5rUm .

(2) Schiermeier Q., et al. "Energy alternatives: Electricity without carbon." Nature News. 454.7206 (2008): 816-823.

(3) Tollefson, J. (2010). Greenhouse-gas numbers up in the air. 18-19.

(4) World Wind Energy Association. “Wind Power Capacity Reaches 539 GW, 52.6 GW Added in 2017.”https://wwindea.org/blog/2018/02/12/2017-statistics/.

(5) Ibid.

(6) Ibid.

(7) U.S. Energy Information Administration. “Hydropower Explained.”https://www.eia.gov/energyexplained/?page=hydropower_home.

(8) U.S. Energy Information Administration. "Solar Explained.”https://www.eia.gov/energyexplained/index.php?page=solar_home.

(9) United Nations Environment Programme (UNEP)."Towards Sustainable Production and Use of Resources: Assessing Biofuels.". https://bit.ly/2Oa0cKx.

(10) International Geothermal Association. “Treasure Under Your Feet: What is Geothermal?”https://www.geothermal-energy.org/explore/what-is-geothermal/.