Presentation on theme: "Chapter 12 Nonrenewable Energy Resources. Energy Efficiency Fuels used for electricity generation in the United States. Coal is the fuel most commonly."— Presentation transcript:
Energy Efficiency Fuels used for electricity generation in the United States. Coal is the fuel most commonly used for electricity generation. [Data from U.S. Department of Energy, Energy Information Administration, 2009.] However… most coal burning power plants are only about 35% efficient.
Process of Energy Use The efficiency of the transfer of energy from a fuel to electricity is approximately 35%. Another 30% is lost during “electricity transmission” from the generator to the user.
The use of Coal as a fuel rose in the late 1800’s. Coal is widely used around the world because: a. coal is plentiful b. resources are relatively easy to exploit c. coal is easily transported d. coal needs little refining e. Coal has a high energy density The drop in the use of coal as a fuel in the 1940s was caused by a rise in the use of natural gas. In 2000, natural gas provided about as much energy as coal. However… the use of coal is continuing to rise world wide due to the increased use of coal in developing countries such as China and India.
AdvantagesDisadvantages Energy-denseContains impurities PlentifulRelease impurities into air when burned Easy to exploit by surface miningTrace metals like mercury, lead, and arsenic are found in coal Technological demands are smallCombustion leads to increased levels of sulfur dioxide and other air pollutants into the atmosphere. Economic costs are lowAsh is left behind Easy to handle and transportCarbon is released into the atmosphere which contributes to climate change Needs little refining Advantages and Disadvantages of Coal Coal is 60-80% carbon. When it is burned, most of that carbon is converted into CO 2. Coal produces far more CO 2 per unit energy released than either oil or natural gas.
Coal Coal- a solid fuel formed primarily from the remains of trees, ferns, and other plant materials that were preserved 280-360 million years ago. Four types of coal ranked from lesser to greater age, exposure to pressure, and energy content. These four types are: lignite, sub-bituminous, bituminous, and anthracite. The largest coal reserves are in the United States, Russia, China, and India.
The use of petroleum as a fuel rose dramatically in the mid 1900’s due to: a.its relative ease of extraction b.its relative ease of transportation c.its use as a transportation fuel d. its relatively inexpensive cost However, a vast majority of U.S. oil is being imported … The United States imports about 30% of our energy needs.
A mixture of hydro- carbons, water, and sulfur that formed from the remains of ocean-dwelling phytoplankton that died 50-150 million years ago and occurs in under- ground deposits. The fluid nature of oil and gasoline make this ideal for mobile combustion, such as vehicles. Countries with the most petroleum are Saudi Arabia, Russia, Iran, China, Canada, and Mexico. Petroleum
AdvantagesDisadvantages Convenient to transport and useReleases carbon dioxide into atmosphere Relatively energy-densePossibility of leaks when extracted and transported Cleaner-burning than coalSignificant imports create dependency on foreign countries Releases sulfur, mercury, lead, and arsenic into the atmosphere when burned Advantages and Disadvantages of Petroleum
Natural gas- exists as a component of petroleum in the ground as well as in gaseous deposits separate from petroleum. methane Contains 80 to 95 percent methane and 5 to 20 percent ethane, propane, and butane. Natural Gas
AdvantagesDisadvantages Contains fewer impurities and therefore emits almost no sulfur dioxide or particulates When unburned, methane escapes into the atmosphere “Clean Coal” - Emits only 60% as much carbon dioxide as coal Exploration of natural gas: “ Fracking ” contaminates groundwater with carcinogenic (cancer-causing) chemicals Land experiences degradation due to drilling techniques and pipelines are built through environmentally sensitive areas Advantages and Disadvantages of Natural Gas
Oil sands Oil sands - slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay. Bitumen Bitumen (tar or pitch)- a degraded type of petroleum that forms when a petroleum migrates close to the surface, where bacteria metabolize some of the light hydrocarbons and others evaporate. Other Fossil Fuels
Hubbert curve Hubbert curve - a graph that shows the point at which world oil production would reach a maximum and the point at which we would run out of oil. The Hubbert Curve
less than 40 years If current global use continues, we will run out of conventional oil in less than 40 years. at least 200 years Coal supplies will last for at least 200 years, and probably much longer. The Future of Fossil Fuel Use