unit 4 energy test
1. Summarize the potential for greatly increased production of oil and natural gas in the United States and describe two major problems to be overcome.
. There has been an increase in production of oil ever since 2008, primarily due to high oil pries and improved drilling and extraction technology. Oil has become more profitable to extract. If oil production increases continuously, and oil prices remain at $50 a barrel or higher, the United States could become the world's largest oil producer before 2020. There are two major problems to overcome: 1. The large scale removal of natural gas and oil held tightly in shale rock requires huge amounts of water and also produces heavily polluted wastewater. 2. By burning more carbon-containing oil, natural gas and coal, we will continue to release growing amounts of CO2 and methane into the atmosphere faster than they can be removed.
Describe the potential for using renewable energy from the wind to produce most of the electricity used in the United States.
1. Wind power is an indirect form of solar energy; it is a way to apply the solar energy principle of sustainability. We capture this energy with groups of wind turbines called wind farms that convert it into electrical energy that can be fed into electrical grids. Wind power is widely distributed and inexhaustible. The US Department of Energy (DOE) estimates that wind farms. At favorable sites in three states- North Dakota, Kansas, and Texas- could more than meet the electricity of the lower 48 states.
10. Core Case Study What are this chapter's three big ideas? Explain how the chemical cycling, biodiversity, and full-cost pricing principles of sustainability (see Figure 1-2, and Figure 1-5) could be applied to our future energy resource choices.
10. BIG IDEAS: 1. A key factor to consider in evaluating the long-term usefulness of any energy resource is its net energy yield. 2. Conventional oil, natural gas, and coal are plentiful and have moderate to high net energy yields, but use of these fossil fuels, especially coal, has a high environmental impact. 3. The nuclear power fuel cycle has a low environmental impact and a very low accident risk, but high costs, a low net energy yield, long-lived radioactive wastes, and its role in spreading nuclear weapons technology have limited its use. By reusing and recycling more of materials we use in our daily lives and in industry and transportation, we could cut our need for energy, raising net energy yields, an application of chemical cycling. Also, full cost pricing to all energy resources give us more realistic understanding of true economic and environmental costs of using nonrenewable fossil fuels and nuclear power.
Section 16-8 10. Core Case Study What is the key concept for this section? List eight questions that policy makers should ask about each source of energy. List three general conclusions that energy experts have come to in considering possible energy futures. List five major strategies suggested by such experts for making the transition to a more sustainable energy future. Explain three strategies that governments can use to encourage or discourage the use of an energy resource. What are this chapter's three big ideas? Explain how we would be applying the six principles of sustainability by improving energy efficiency and shifting to renewable energy resources.
10. Key Concept: We can make the transition to a more sustainable energy future by greatly improving energy efficiency, using a mix of renewable energy resources, and including the environmental and health costs of energy resources in their market prices. Eight questions: 1. How much of the energy resource is likely to be available in the near future (the next 25 years) and in the long term (the next 50 years)? 2. What is the estimated net energy yield for the resource? 3. What are the estimated costs for developing, phasing in, and using the resource? 4. What kinds of government research and development subsidies and tax breaks will be needed to help develop the resource? 5. How will dependence on the resource affect national and global economic and military security? 6. How vulnerable is the resource to terrorism? 7. How will extracting, transporting, and using the resource likely affect the environment, the earth's climate, and human health? 8. Does use of the resource produce hazardous, toxic, or radioactive substances that we must safely store for very long periods of time? Three general conclusions: during this century, there will likely be a gradual shift from large, centralized macro-power systems to a smaller, decentralized micro-power systems. Shift from gasoline powered motor vehicles to hybrid and plug in electric cars. 2. Combination of improved energy efficiency and carefully regulated use of natural gas will be best way to make transition to using mostly renewable energy resources during this century. 3. Fossil fuels are still abundant and artificially cheap, we will continue to use them in large quantities. Five strategies:1. Increase fuel-efficiency standards for vehicles, building and appliances. 2. Reward utilities for reducing demand for electricity. 3. Greatly increase energy efficiency research and development. 4. Greatly increase use of renewable energy. 5. Levy taxes on coal and oil use. Encourage: 1. Keep prices of selected energy resources artificially low to encourage use of those resources. 2. Subsidies, tax breaks and loan guarantees to encourage the development of those resources and enacting regulations that favor them. 2. Allow prices of selected energy resources to rise their natural market levels by removing government subsidies, thereby discouraging the use oft these resources. 3. Emphasize consumer education. BIG IDEAS: 1.We should evaluate energy resources on the basis of their potential supplies, their net energy yields, and the environmental and health impacts of using them. 2. By using a mix of renewable energy sources—especially solar, wind, flowing water, sustainable biofuels, and geothermal energy—we could drastically reduce pollution, greenhouse gas emissions, and biodiversity losses. 3. Making the transition to a more sustainable energy future will require sharply increasing energy efficiency, using a mix of environmentally friendly renewable energy resources, and including the harmful environmental and health costs of energy resources in their market prices. Relying mostly on nonrenewable fossil fuels and nuclear power violates the three scientific principles of sustainability. Relying more on diversity of direct and indirect forms of renewable solar energy coupled with improving energy efficiency to reduce unnecessary waste of energy and money. Making shift to more sustainable energy future involves: relying much more on direct and indirect forms of solar energy for our electricity, heating and cooling, and other needs; recycling and reusing more materials and thus reducing wasteful and excessive consumption of energy and matter; and mimicking nature's reliance on biodiversity by using a diverse mix of locally and regionally available renewable energy resources.
Section 15-1 2. What is the key concept for this section? What is net energy yield and why is it important in evaluating energy resources? Explain why some energy resources need help in the form of subsidies to compete in the marketplace, and give an example.
2. KEY concept: Energy resources vary greatly in their net energy yields—the amount of energy available from a resource minus the amount of energy needed to make it available. Net energy yield: Total amount of useful energy available from an energy resource or energy system over its lifetime, minus the amount of energy used (the first energy law), automatically wasted (the second energy law), and unnecessarily wasted in finding, processing, concentrating, and transporting it to users. There is a rule to evaluate long-term economic usefulness of an energy resource: 'an energy resource with a low or negative net energy yield can have a hard time competing in the market place with other energy alternatives that have medium to high net energy yields unless it receives financial support from the government (taxpayers) or other outside sources". Some energy resources need financial support, subsidies, or subsidizing because some subsidies help to hide the true cost of the nuclear power fuel cycle and violate full cost pricing principle of sustainability. An example: electricity produced by nuclear power has a low net energy yield because large amounts of high quality energy are needed for each step in the nuclear power fuel cycle to extract uranium ore, convert it into nuclear fuel, build and operate nuclear power plants, safely store the resulting highly radioactive wastes for thousands of years and dismantle each plant after its useful life and safely store its high-level radioactive parts for thousands of years. Result low net energy yield for the whole nuclear fuel cycle is one reason why governments throughout the world heavily subsidize nuclear power to make it available to consumers at an affordable price.
Section 16-1 2. What are the two key concepts for this section? What is energy efficiency? Explain why we can think of energy efficiency as an energy resource. What percentage of the energy used in the United States is unnecessarily wasted? List five widely used energy-inefficient technologies. What are the major advantages of reducing energy waste? List four ways to save energy and money in industry. What is cogeneration? How can electric utility companies help people reduce their energy waste? What is a smart grid and why is it important? What are the hidden costs of using gasoline?
2. Two key concepts: 1. Improvements in energy efficiency could save at least a third of the energy used in the world and up to 43% of the energy used in the United States. 2. We have a variety of technologies for sharply increasing the energy efficiency of industrial operations, motor vehicles, appliances, and buildings. Energy efficiency: Percentage of the total energy input that does useful work and is not converted into low-quality, generally useless heat in an energy conversion system or process. We can improve energy efficiency by using less energy to provide the same amount of work in the forms of light, heat, transportation, and other benefits. This amounts to a largely untapped source of energy that is abundant, clean, cheap, and readily available. 84% of all commercial energy used in the United States does not produce useful work. 41% of this energy unavoidably ends up as low-quality waste heat in the environment because of the degradation of energy quality imposed by the second law of thermodynamics. 43% of it is wasted unnecessarily because of inefficiency of light bulbs., industrial motors, motor vehicles, and power plants. 1 Huge data centers, 2. Internal combustion engine, 3. Nuclear power plant, 4. Coal-fired power plants. Improve: 1. Prolongs fossil fuel supplies, 2. Reduces oil imports and improves energy security, 3. Very high net energy yield, 4. Low cost, 5. Reduces pollution and environmental degradation, 6. Buys time to phase in renewable energy, 7. Creates local jobs. Cogeneration: Production of two useful forms of energy, such as high-temperature heat or steam and electricity, from the same fuel source. They can use more energy-efficient electric motors, recycle materials, combined heat and power system. A smart grid system is an energy efficient, digitally controlled, ultra high voltage system with superefficient transmission lines. A smart grid could adapt to a disaster that causes a power loss in one area by quickly bringing in electricity from other parts of the country. It would use smart meters to monitor the amount of electricity used and the patterns of use for each customer. The hidden costs not included in the price include government subsidies and tax breaks for oil companies, car manufacturers and road builders; costs of pollution control and cleanup; time wasted idling in traffic jams; and higher medical bills and health insurance premiums resulting from illnesses caused by air and water pollution. Gas for US consumers were about $3.18 per liter.
Section 15-2 3. What are the two key concepts for this section? What is crude oil (petroleum), and how are oil deposits detected and removed? What percentages of the commercial energy used in the world and in the United States are provided by conventional crude oil? What is the peak production for an oil well and for the world oil deposits? What is refining? What are petrochemicals and why are such chemicals important? What countries are the world's three largest producers of oil and what countries are the three largest consumers?
3. KEY concepts: Conventional crude oil is abundant and has a medium net energy yield, but using it causes air and water pollution and releases greenhouse gases to the atmosphere. Unconventional heavy oil from oil shale rock and tar sands exists in potentially large supplies but has a low net energy yield and a higher environmental impact than conventional oil has. Crude oil (petroleum) is Gooey liquid consisting mostly of hydrocarbon compounds and small amounts of compounds containing oxygen, sulfur, and nitrogen. Extracted from underground accumulations, it is sent to oil refineries, where it is converted to heating oil, diesel fuel, gasoline, tar, and other materials. Oil deposits are found by large machines that pound the earth, sending shock waves deep underground, and measuring how long it takes for the waves to be reflected back. The info is sent to computers and changed into 3-D seismic maps of the underground that show the locations and sizes of various rock formations. Then oil companies drill holes and remove rock cores from potential oil deposit areas to learn whether there is enough oil to be extracted profitably. Coal supplies 52% of the electricity generated in the United States. Peak production: Point in time when the pressure in an oil well drops and its rate of conventional crude oil production starts declining, usually a decade or so; for a group of wells or for a nation, the point at which all wells on average have passed peak production. For an oil well, it is usually a decade. Refining: Complex process in which crude oil is heated and vaporized in giant columns and separated, by use of varying boiling points, into various products such as gasoline, heating oil, and asphalt. Petrochemicals: Chemicals obtained by refining (distilling) crude oil. They are used as raw materials in manufacturing most industrial chemicals, fertilizers, pesticides, plastics, synthetic fibers, paints, medicines, and many other products. Producers: 1. Saudi Arabia, Russia, United States. Users: United States, China, Japan.
3. What are four ways to save energy and money in transportation? Summarize the development of more energy-efficient vehicles. Explain the importance of developing better batteries and list some advances in this area. What are fuel cells and what are their advantages? What are some technologies applied by green architecture? Explain benefits of living roofs. List four ways to improve energy efficiency in new buildings and eight ways to improve energy efficiency in existing buildings. List six ways in which you can save energy where you live. Give three reasons why we waste so much energy. List five advantages of relying more on a variety of renewable energy sources and list three factors that are holding back such a transition.
3. Save energy: 1. Building or expanding mass transit systems within cities, constructing high-speed trial lines between cities, carrying more freight by rail instead of in heavy trucks, encourage bicycle use by building bike lanes along highways and on city streets. A conventional gasoline electric hybrid vehicle is powered by small internal combustion engine with an assist from a strong battery. A plug in hybrid electric vehicle has smaller internal combustion engines with larger and more powerful battery that can be plugged into a 110-volt or 220-volt outlet and recharged. An all electric vehicle runs completely on rechargeable battery. Important factors will be to build a network of recharging stations in many convenient locations within and between communities. Promising batteries: lithium-ion battery. They are light and can pack a lot of energy into a small space. By hooking many of them together, we can use them to power hybrid, plug-in hybrid and all electric motor vehicles. We need better batteries because the obstacle is standing the way of wider use of plug in hybrid electric and all electric vehicles is the lack of an affordable, small, lightweight and easily rechargeable car battery that can store energy to power a vehicle over long distances. Fuel cells: device that uses hydrogen gas as a fuel to produce electricity. Fuel cells are at least twice as efficient as internal combustion engines have no moving parts and require little maintenance. Energy efficient, resource efficient and money saving designs employs several old and new technologies for green architecture, and natural lighting, direct solar heating, insulated windows, energy efficient appliances and lighting, solar hot water heaters, electricity from solar cells, windows that darken automatically to deflect heat from the sun, thin sheets of aerogel insulation and recycling of wastewater. Living roofs covered with specially designed soil and vegetation. Roof can reduce costs of cooling and heating a building by absorbing heat from summer sun and helping insulate structure and retain heat in the winter. Absorbs precipitation, which would normally become part of city's storm water runoff, adding to pollution of its waterways. 1. Insulate building and plug leaks. 2. Use energy-efficient windows. 3. Stop other heating and cooling losses. 4. Heat houses and other buildings more efficiently. 5. Heat water more efficiently. 6. Use energy efficient appliances. 7. Stop using standby mode. 8. Use energy efficient computers. 9. Use energy efficient lighting. 10. Use automatic motion sensors to turn lights on and off as needed. Where you live: use compact fluorescent light bulbs or LEDs and avoid using incandescent bulbs. 2. Use house fans. 3. Hang reflective foil near roof to reflect heat. 4. Clean refrigerator coils regularly. 5. Hang clothes on racks for drying. 6. Insulate exposed hot water pipes. 7. Use fans instead of air conditioning. 8. Keep heating and cooling vents free of obstructions. Waste energy: 1. US uses resources like fossil fuels and nuclear power are artificially cheap. 2. Gov. subsidies and tax breaks they receive bc market prices do not include harmful environmentally and health costs of production and use. 3. Few gov. tax breaks. We can get renewable solar energy from sun or from wind, flowing water, biomass, none of which would exist without direct solar energy. With consistent government backing in form of research and development funds and subsidies and tax breaks, renewable energy could give 20% of world's electricity by 2025 and 50% by 2050. First, since 1950, government tax breaks, subsidies, and funding for research and development of renewable energy resources have been much lower than those for fossil fuels (especially oil) and nuclear power, although subsidies and tax breaks for renewables have increased in recent years. Second, although subsidies and tax breaks for fossil fuels and nuclear power have essentially been guaranteed for many decades, those for renewable energy in the United States have to be renewed by Congress every few years. The resulting financial uncertainty makes it risky for companies to invest in renewable energy. Third, the prices we pay for nonrenewable fossil fuels and nuclear power do not include the harmful environmental and human health costs of producing and using them. This helps to shield them from free-market competition with renewable sources of energy.
Section 16-2 4. What is the key concept for this section? Distinguish between a passive solar heating system and an active solar heating system and discuss the major advantages and disadvantages of using such systems for heating buildings. What are three ways to cool houses naturally? What are solar thermal systems, how are they used, and what are the major advantages and disadvantages of using them? What is a solar cell (photovoltaic or PV cell) and what are the major advantages and disadvantages of using such devices to produce electricity?
4. Key Concept: massive and active solar heating systems can heat water and buildings effectively, and the costs of using direct sunlight to produce high-temperature heat and electricity are coming down. Passive solar heating system: System that, without the use of mechanical devices, captures sunlight directly within a structure and converts it into low-temperature heat for space heating or for heating water for domestic use. Active solar heating system: System that uses solar collectors to capture energy from the sun and store it as heat for space heating and water heating. Liquid or air pumped through the collectors transfers the captured heat to a storage system such as an insulated water tank or rock bed. Pumps or fans then distribute the stored heat or hot water throughout a dwelling as needed. Advantages: medium net energy yield, very low emissions of CO2 and other air pollutants, very low land disturbance, moderate cost (passive). Disadvantages: need access to sun 60% of time during daylight, sun can be blocked by trees and other structures, high installation and maintenance costs for active systems, need backup system for cloudy days. Naturally: block high summer sun with shade trees, broad overhanging eaves, window awnings or shads, 2. In warm climates, use a light colored roof to reflect as much as 90% of sun's heat, or use a green roof, 3. Use geothermal heat pumps for cooling and heating in winter. Solar thermal systems: System that uses any of various methods to collect and concentrate solar energy in order to boil water and produce steam for generating electricity. They use different methods to collect and concentrate solar energy in order to boil water and produce steam for generating electricity. Advantages: high potential for growth, no direct emissions of Co2 and other air pollutants, lower costs with natural gas turbine backup, source of new jobs. Disadvantages: low net energy yield and high costs, needs backup or storage system on cloudy days, requires high water use, can disrupt desert ecosystems. photovoltaic (PV) cells: Device that converts radiant (solar) energy directly into electrical energy. Also called a solar cell. Advantages: medium et energy yield, little or no direct emissions of Co2 and other air pollutants, easy to install, move around and expand as needed, and competitive cost for newer cells. Disadvantages: need access to sun, some designs have low net energy yield, need electricity storage system or backup, costs high for older systems but dropping rapidly, solar-cell power plants could disrupt desert ecosystems.
4. What are proven oil reserves and what five factors determine such reserves? Define horizontal drilling and hydraulic fracturing or fracking and explain how these two technologies are being used to extract tightly held oil and natural gas from shale rock. What three countries have the largest percentages of the world's proven oil reserves? What percentages are found in the United States and China? Based on data from the U.S. Department of Energy and the U.S. Geological Survey, what are three conclusions that have been drawn concerning consumption of conventional light oil? What are the major environmental costs of using oil? What are the major advantages and disadvantages of using conventional light oil as an energy resource? Describe U.S. dependence on oil and on imported oil. How can U.S. oil production increase dramatically in coming years, according to some analysts? What are two factors that could limit such an increase in domestic oil production?
4. Proven Oil Reserves: Identified deposits from which conventional crude oil can be extracted profitably at current prices with current technology. Five factors: 1. Demand for oil, 2, technology used to make it available, 3. Rate at which we can remove the oil, 4. Cost of making it available, 5. Market price. Horizontal drilling: Method for extracting oil or natural gas from underground deposits by first drilling down and then using a flexible drilling bore to drill horizontally to gain greater access to oil and gas deposits. Hydraulic fracturing or fracking: Freeing oil or natural gas that is tightly held in rock deposits by using perforated drilling well tubes with explosive charges to create fissures in rock and then using high pressure pumps to shoot a mixture of water, sand, and chemicals into the well to hold the rock fractures open and release the oil or natural gas, which flows back to the surface along with a mixture of water, sand, fracking chemicals, and other chemicals (some of them hazardous) that are released from the rock. Both methods gain greater access to oil and gas deposits. Hydraulic is used to free the tightly held oil and natural gas. Largest percentages of world's proven oil reserves: Venezuela, Saudi Arabia, and Canada. USA: 2% 1%. China: 2%, 1%. 1. Saudi Arabia could supply the world's demand for oil for about 7 years. 2. Estimated unproven crude oil reserves under Alaska' Arctic National Wildlife Refuge, would meet world's demand for 1-5 months and US demand for 7-24 months. 3. Arctic Circle holds enough technically recoverable crude oil to meet global demand for about 3 years at high production cost. Environmental costs: land disruption, greenhouse gas emissions, air pollution, water pollution, loss of biodiversity. Advantages: ample supply for several decades, net energy yield is medium but decreasing, low land disruption, efficient distribution system. Disadvantages: water pollution from oil spills and leaks, environmental costs not included in market price, releases CO2 and other air pollutants when burned, vulnerable to international supply interruptions. United States gets about 87% of commercial energy from fossil fuels and 37% coming from oil. United States uses about 21% of oil produced globally but produces 9% of world's oil and has only about 2% of world's proven conventional oil reserves. Analysts state that increased production of oil from shale rock could continue to reduce US dependence on imported oil. Limits: energy, money and water.
5. Explain how we can get heavy oil from oil shale rock and from tar sands (oil sands). What are the major advantages and disadvantages of using heavy oils produced from tar sands and from oil shale rock?
5 We can get heavy oil from shale rock that is produced by mining, crushing and heating oil shale rock to extract a mixture of hydrocarbons called kerogen that can be distilled to produce shale oil. Before shale oil sent to refinery it is heated to increase flow rate and remove sulfur, nitrogen and impurities which decreases its net energy yield. Tar Sands or Oil Sands: Deposit of a mixture of clay, sand, water, and varying amounts of a tarlike heavy oil known as bitumen. Bitumen can be extracted from tar sand by heating. It is then purified and upgraded to synthetic crude oil. Advantages; large potential supplies, easily transported within and between countries, efficient distribution system in place. Disadvantage: low net energy yield, releases CO2 and more air pollutants when made and burned, 3, severe land disruption and high water use.
Section 16-3 5. What is the key concept for this section? Define hydropower and summarize the potential for expanding it. What are the major advantages and disadvantages of using hydropower? What is the potential for using tides and waves to produce electricity?
5. Key Concepts: We can use water flowing over dams, tidal flows, and ocean waves to generate electricity, but environmental concerns and limited availability of suitable sites may limit the use of these energy resources. Hydropower: Electrical energy produced by falling or flowing water. The United Nations, 13% of world's potential for hydropower has been developed, much of untapped potential is in China, India, South America, Central Africa, and parts of Soviet Union. China has plans to double hydropower output during next decade. Most common approach to harnessing hydropower is to build a high dam across a large river to create a reservoir. Advantages: high net energy yield, large untapped potential, low-cost electricity, low emissions of CO2 and other air pollutants in temperate areas. Disadvantages: large land disturbance and displacement of people, high CH4 emissions from rapid biomass decay in shallow tropical reservoirs, disrupts downstream aquatic ecosystems. Tides and waves are limited systems to the small number of rivers that have adequate tidal flows. Limited because of lack of suitable sites, citizen opposition at some sites, high costs and equipment damage from saltwater corrosion and storms.
Section 5-3 6. What is the key concept for this section? Define natural gas, liquefied petroleum gas (LPG), and liquefied natural gas (LNG). What countries have the three largest portions of the world's proven natural gas reserves? What percentages of the world's reserves are held by the United States and China? What are the major advantages and disadvantages of using conventional natural gas as an energy resource? Why has natural gas production risen sharply in the United States and what two factors could hinder this rise? Describe five major problems resulting from increased use of fracking to produce natural gas in the United States and six ways to deal with these problems. What are two other sources of unconventional natural gas and what major problems are related to the use of these resources?
6. KEY concept: Conventional natural gas is more plentiful than oil, has a medium net energy yield and a fairly low production cost, and is a clean-burning fuel, but producing it has created environmental problems. Natural gas: Underground deposits of gases consisting of 50-90% by weight methane gas and small amounts of heavier gaseous hydrocarbon compounds such as propane and butane . Liquefied petroleum gas (LPG): Mixture of liquefied propane and butane gas removed from natural gas and used as a fuel. liquefied natural gas (LNG): Natural gas converted to liquid form by cooling it to a very low temperature. 1. Russia, 2. Iran, 3. Qatar. China and India: 1.5% and 0.6% respectively. USA has 4%. Advantages: ample supplies, versatile fuel, medium net energy yield, emits less CO2 and other air pollutants than other fossil fuels when burned. Disadvantages: low net energy yield for LNG, production and delivery may emit more CO2 and CH4 per unit of energy produced than coal, fracking uses and pollutes large volumes of water, and potential groundwater pollution from fracking. Five problems with fracking: 1. Uses enormous volumes of water. 2. Fracking fluids contain hazardous chemicals that used to reduce friction, inhibit corrosion and stop bacterial growth, 3. Fracking requires special type of sand, so some areas are seeing boom in mining of this sand like western Wisconsin, 4. Small earthquakes are created, 5. Climate changing CH4 and CO2 are emitted. Solutions: 1. Step up research, 2. Increase monitoring and legal regulation of natural gas production, 3. Developed federal regulations on disposal, storage, treatment and reuse of fracking wastewater, 4. Require disclosure of all chemicals used in fracking, 5. Require use of least harmful chemicals available in fracking fluids, 6. Require testing of aquifers and drinking water wells for any chemical contamination, 7. Overturn all exemptions for oil and natural gas production from any and all federal pollution regulations. Two other sources: coal bed methane gas, 2. Methane hydrate. They both have environmental impacts: pollution of aquifers, depletion of water sources, releases of methane to atmosphere speed up atmospheric warming and resulting climate disruption.
Section 16-4 6. What is the key concept for this section? What are the advantages of using taller wind turbines? Summarize the global potential for wind power. What are the major advantages and disadvantages of using wind to produce electricity?
6. Key Concept: When we include the environmental costs of using energy resources in their market prices, wind power is the least expensive and least polluting way to produce electricity. Advantages: long blades to get more energy from wind more efficiently than smaller turbines, generate more energy with fewer turbines and lower land and ecological footprint than those with smaller turbines, help lower price of wind energy. Advantages: high net energy yield, widely available, low electricity cost, little or no direct emissions of CO2 and other air pollutants, easy to build and expand. Disadvantages: needs backup or storage system when winds die down, visual pollution for some people low-level noise brothers some people, can kill birds if not properly designed and located. Wind power has been the world's second fastest-growing source of energy after solar cells with more than 80 countries now harnessing energy from the wind. Wind is abundant, widely distributed and inexhaustible.
Section 15-4 7. What are the two key concepts for this section? What is coal and how is it formed? How does a coal-burning power plant work? What percentage of the electricity used in the world and in the United States comes from burning coal in power plants? What three countries have the largest proven reserves of coal? What are three major problems resulting from the use of coal? Explain why there is no such thing as clean coal. What are the major advantages and disadvantages of using coal as an energy resource? What are the major advantages and disadvantages of using synthetic natural gas (SNG) produced from coal?
7. KEY concepts: Conventional coal is plentiful and has a high net energy yield at low costs, but using it results in a very high environmental impact. We can produce gaseous and liquid fuels from coal, but they have lower net energy yields and using them would result in higher environmental impacts than those of conventional coal. Coal: Solid, combustible mixture of organic compounds with 30-98% carbon by weight, mixed with various amounts of water and small amounts of sulfur and nitrogen compounds. It forms in several stages as the remains of plants are subjected to heat and pressure over millions of years. Coal burned in power plants to generate 45% of world's electricity. Power plants burn pulverized coal to boil water and produce steam that spins a turbine to produce electricity. 45% of world' electricity, SUA: 53% but dropped to 37$ in 2012 and could drop to 30$ by 2020. Coal is abundant, five countries have 3/4ths of the world's proven coal reserves. USA: 28% of global coal reserves. Russia with 18% and China with 13%. Problem: air pollution, solid industrial waste, toxic chemicals. Coal will never be clean because it is mostly carbon with small amounts of sulfur, which is converted to air pollutant sulfur dioxide and when coal burns it releases black carbon particulates or soot. Advantages: ample supplies in many countries, medium to high net energy yield, low cost when environmental costs are not included. Disadvantages: severe land disturbance and water pollution, fine particle and toxic mercury emissions threaten human health, emits large amounts of CO2 and other air pollutants when produced and burned. synthetic natural gas (SNG) Gaseous fuel containing mostly methane produced from solid coal. Advantages: large potential supply in many countries, vehicle fuel, lower air pollution than coal. Disadvantages: low to medium net energy yield, requires mining 50% more coal with increased land disturbance, water pollution and water use, higher CO2 emissions than coal.
Section 16-5 7. What are the two key concepts for this section? What is biomass and what are the major advantages and disadvantages of using wood to provide heat and electricity? What are the major advantages and disadvantages of using biodiesel and ethanol to power motor vehicles? Explain how algae and bacteria can be used to produce fuels nearly identical to gasoline and diesel fuel.
7. Key Concepts: Solid biomass is a renewable resource for much of the world's population, but burning it faster than it is replenished produces a net gain in atmospheric greenhouse gases. We can use liquid biofuels derived from biomass to lessen our dependence on oil-based fuels, but creating biofuel plantations can degrade soil and biodiversity, increase greenhouse gas emissions, and lead to higher food prices. Biomass: consists of plant materials (such as wood and agricultural waste) that we can burn directly as a solid fuel or convert into gaseous or liquid biofuels. Advantages: widely available in some areas, moderate costs, medium net energy yield, no net CO2 increase if harvested, burned, and replanted sustainably, plantations can help restore degraded lands. Disadvantages: contributes to deforestation, clear cutting can cause soil erosion, water pollution and loss of wildlife habitat, can open ecosystem to invasive species, increases CO2 emissions of harvested and burned unsustainably. Advantages of using liquid biofuels: reduced CO2 emissions for some crops, medium net energy yield for biodiesel from oil palms, medium net energy yield for ethanol from sugarcane. Disadvantages: fuel crops can compete with food crops for land and raise food prices, fuel crops can be invasive species, low net energy yield for corn ethanol and for biodiesel for soybeans, higher CO2 emissions form corn ethanol. Also, biofuels have advantages over gasoline and diesel fuel produced from oil: First, biofuel crops can be grown throughout much of the world, and thus they can help countries to reduce their dependence on imported oil. Second, if these crops are not used faster than they are replenished by new plant growth, there is no net increase in emissions, unless existing grasslands or forests are cleared to plant biofuel crops. Third, biofuels are easy to store and transport through existing fuel networks and can be used in motor vehicles at little or no additional cost. Algae and bacteria can be used to produce fuels. Algae removes CO2 from the atmosphere and converts it into oil as it grows. They require much less land, water and other resources than biofuel plantations do and would not affect food prices by competing for cropland. Also, bacteria can be multiplied by using techniques developed in the new field of synthetic biology.
Section 15-5 8. What is the key concept for this section? How does a nuclear fission reactor work and what are its major safety features? Describe the nuclear fuel cycle. What are three ways to decommission a nuclear power plant at the end of its useful life? What are the major advantages and disadvantages of relying on the nuclear fuel cycle as a way to produce electricity? How do nuclear plant operators store highly radioactive spent-fuel rods? Why is dealing with the highly radioactive wastes produced by the nuclear fuel cycle such a difficult problem? Explain why nuclear power is not likely to reduce U.S. dependence on imported oil and why it is not likely to reduce projected climate disruption.
8. KEY: Nuclear power has a low environmental impact and a very low accident risk, but its use has been limited by a low net energy yield, high costs, fear of accidents, long-lived radioactive wastes, and its role in spreading nuclear weapons technology. Fission takes place in a reactor. Most common reactors: light-water reactors create 85% of world's nuclear generated electricity. Safety features: fuel rods, fuel assemblies, control rods, containment shell. Nuclear fuel cycle: Includes the mining of uranium, processing and enriching the uranium to make nuclear fuel, using it in the reactor, safely storing the resulting highly radioactive wastes for thousands of years until their radioactivity falls to safe levels, and retiring the highly radioactive nuclear plant by taking it apart and storing its high- and moderate-level radioactive material safely for thousands of years. Advantages: low environmental impact, emits 1/6 as much CO2 as coal, low risk of accidents in modern plants. Disadvantages: low net energy yield, high overall cost, produces long lived harmful radioactive wastes, promotes spread of nuclear weapons. Reactors shut down for refueling which involves replacing about a third of reactor's fuel rods that contain spent fuel. Single spent fuel rod assemblies are removed from reactors, stored in water- filled pools and can be transferred to dry casks make of heat resistant metal alloys and concrete and filled with inert helium gas. Its difficult because they are vulnerable to sabotage or terrorist attack because they lie outside of protected reactor containment buildings. USA abandoned this fuel recycling approach in 1977 because of the costly reprocessing. Steps to dismantling nuclear plants: store highly radioactive parts in a permanent secure repository, install physical barrier around plant with full time security for 30-100 years, enclose entire plant in concrete and steel reinforced tomb called a containment structure.
Section 16-6 8. What is the key concept for this section? What is geothermal energy and what are three sources of such energy? What are the major advantages and disadvantages of using geothermal energy as a source of heat and to produce electricity?
8. Key Concept: Geothermal energy has great potential for supplying many areas with heat and electricity, and has a generally low environmental impact, but the sites where it can be produced economically are limited. Geothermal energy: Heat transferred from the earth's underground concentrations of dry steam (steam with no water droplets), wet steam (a mixture of steam and water droplets), or hot water trapped in fractured or porous rock. It is stored in soil, underground rocks and fluids in earth's mantle. Advantages: medium net energy yield and high efficiency at accessible sites, lower CO2 emissions than fossil fuels, low cost at favorable sites. Disadvantages: high cost except at concentrated and accessible sources, scarcity of suitable sites, noise and some CO2 emissions.
9. Compare the projections for growth of the nuclear industry in the 1950s with its actual role now in generating electricity. What is the role of government subsidies in nuclear power? List and explain three major factors that have kept nuclear power from growing. What is the connection between commercial nuclear power plants and the spread of nuclear weapons? Describe the 2011 nuclear power plant accident in Japan. Define nuclear fusion, and summarize the story of attempts to develop it as an energy resource.
9. 1950s: researchers said by 2000 at least 1,800 nuclear power plants would supply 21% of world's commercial energy and most of world' electricity. Today: some 432 commercial nuclear reactors in 21 countries produced 5% of world's commercial energy and 15% of electricity. In 2013, 60 new nuclear reactors under construction in 13 countries, far from number needed just to replace reactors that will have to be decommissioned in coming years. It is controversial and widely debated (the future of nuclear power) because people say that nuclear power industry could not exist without high levels of financial support from governments and taxpayers. Obstacles for growth: public concerns about safety of nuclear reactors, nuclear weapons, nuclear energy and research development. Much of information used to sell commercial nuclear reactors and uranium fuel enrichment and purification technology for decades is needed to produce nuclear weapons. In 2011, at Fukushima Daiichi Nuclear Power plant in Japan, accident triggered by offshore earthquake caused a tsunami that crashed over nuclear plant protective seawalls and knocked out circuit and exploded and blew off three of reactor building's roofs and released radioactivity into atmosphere. Nuclear fusion: is nuclear change at the atomic level in which the nuclei of two isotopes of a light element such as hydrogen are forced together at extremely high temperatures until they fuse to form a heavier nucleus, releasing energy in the process. In the USA; after 50+ years of research and $25 billion investment, controlled nuclear fusion is still in the laboratory stage. None of approaches tested so far has made more energy than they use.
Section 16-7 9. What is the key concept for this section? What are the major advantages and disadvantages of using hydrogen as a fuel to use in producing electricity and powering vehicles?
Key Concept: Hydrogen is a clean energy source as long as it is not produced with the use of fossil fuels, but it has a negative net energy yield. Advantages: can be produced from plentiful water at some sites, no CO2 emissions if produced with use of renewables, good substitute for oil, high efficiency in fuel cells. Disadvantages: negative net energy yield, CO2 emissions if produced from carbon-containing compounds, high costs create need for subsidies, needs H2 storage and distribution system.
