APES Unit 9 overall notes

Briefing Document: Energy Resources and Environmental Impacts

I. Executive Summary:

This document summarizes key information regarding energy resources, focusing on both non-renewable (fossil fuels and nuclear) and renewable options. It addresses the advantages and disadvantages of each, considering environmental impacts, human health concerns, energy efficiency, and the role of different countries in energy production and consumption. The importance of net energy yield is emphasized as a crucial factor in evaluating the long-term viability of energy resources.

II. Non-Renewable Energy Sources:

• Overall Dependence: A significant portion (90%) of global commercial energy comes from non-renewable resources, including oil, natural gas, coal, and nuclear energy.

• Net Energy: The concept of "Net energy yield" is central to evaluating energy resources. It is defined as "Amount of high-quality energy available from a resource minus the high-quality energy needed to make the energy available." The "net energy ratio" is also called "energy returned on investment."

• Oil:Abundance & Drawbacks: Conventional crude oil is abundant but causes air and water pollution and releases CO2. Unconventional heavy oil sources (oil shale, tar sands) have potentially large supplies but a low net energy yield and higher environmental impact.

• Hydrofracking: A core case study focuses on hydrofracking, which involves "pump[ing] water, sand, and chemicals into cracks" to extract oil and natural gas from shale rock formations. This process generates "hazardous waste slurry."

• U.S. Consumption: The United States consumes more oil than it produces, necessitating imports. Shale oil production in the U.S. is expected to peak around 2020 and then decline.

• Heavy Oil Impacts: The extraction of heavy oil, particularly from oil sands, involves "clear-cutting forests and strip-mining the land," resulting in a low net energy yield and significant pollution.

• Natural Gas:Composition & Extraction: Primarily methane, with smaller amounts of propane, butane, and hydrogen sulfide. Extracted via horizontal drilling and fracking.

• Advantages & Disadvantages: Natural gas has a "medium net energy yield and a fairly low production cost" and "burns cleaner than oil and coal." However, fracking has harmful environmental effects, requires large volumes of water, and produces hazardous wastewater that could potentially trigger earthquakes. It also faces potential groundwater contamination from well-casing cement failure. While it emits less CO2 than coal, methane leakage during drilling and distribution can be a significant problem, as methane is a potent greenhouse gas.

• Liquified Natural Gas (LNG): The US exports LNG despite its "Low net energy yield".

• Coal:Abundance & Use: A plentiful but dirty fuel, coal generated 40% of the world’s electricity in 2015. China, the U.S., and India are the largest consumers.

• Environmental Impacts: Burning coal produces significant air and water pollution, including soot, CO2, mercury, and radioactive materials. Mining degrades land, and scrubbers produce coal ash that requires safe storage. "Mining coal severely degrades land".

• Health Impacts: Coal is linked to respiratory diseases like asthma and mercury contamination in tuna.

• Types of Coal: Different types exist, from peat to anthracite, with varying heat and carbon content.

• Synfuels: Coal can be converted to synfuels (synthetic natural gas or liquid fuels), but this is not efficient.

• Nuclear Power:Advantages & Disadvantages: Nuclear power has a "low environmental impact and a very low accident risk," but suffers from "low net energy yield," "high costs," "fear of accidents," "long-lived radioactive wastes," and the potential "role in spread of nuclear weapons technology."

• Reactor Function: Nuclear fission reactors use uranium ore, enriched uranium packed into fuel rods, and control rods to absorb neutrons. Water acts as a coolant. Construction costs are significant ("$9–11 billion"). The United States, France, and Russia are leading producers.

• Nuclear Fuel Cycle: Includes mining, processing, reactor use, waste storage, and plant retirement. There is currently no permanent, secure repository for radioactive waste. "Nevada Yucca Mountain site plan abandoned."

• Accidents: Accidents like Fukushima have increased fear and prompted some countries to phase out nuclear power.

• Fusion: Nuclear fusion is difficult to develop, and no approach has produced more energy than it has used.

III. Renewable Energy Sources:

• General Benefits: Shifting to renewable energy sources can "save money, create jobs, reduce air pollution, [and] keep climate change from accelerating." This shift is driven by "increasing availability of cheaper solar and wind and advances in renewable technology."

• Solar Energy:Active & Passive: Active systems capture heat in a fluid, while passive systems rely on design.

• Solar Thermal Systems: Use sunlight to boil water and generate electricity, primarily in desert regions. "Low net energy yields".

• Photovoltaic (PV) Cells: Convert solar energy into electricity. Emerging technologies are enabling flexible solar cells.

• Germany's Leadership: Germany leads the world in solar power implementation.

• Wind Power:Growth & Potential: Wind is one of the "fastest growing, least expensive, and cleanest ways to produce electricity." The United States, China, and Germany are leading producers.

• Advantages & Disadvantages: Wind power is abundant, widely distributed, inexhaustible, and mostly carbon-free. "High net energy yield". Requires a smart grid for distribution.

• Denmark's Example: Denmark has historically and currently had the highest percentage of its own power from Wind.

• Geothermal Energy:Source: Heat stored in soil, rocks, and fluids in the Earth's mantle.

• Uses: Can be used for heating buildings and generating electricity.

• Geothermal Heat Pump Systems: Utilize the temperature difference between the earth's surface and underground.

• Iceland's Reliance: Geothermal is used exclusively in Iceland.

• Biomass:Solid Biomass: Includes plant materials and agricultural waste burned for fuel. Can lead to deforestation and produce CO2 and pollutants.

• Liquid Biofuels (Ethanol, Biodiesel): Can lessen dependence on oil. However, biofuel crops can degrade soil and biodiversity and increase emissions.

• Corn-Based Ethanol: Has a low net energy and may add more greenhouse gases than gasoline.

• Cellulosic Ethanol: Made from inedible cellulose; considered a better alternative.

• Brazil's Sugarcane Ethanol: "Medium net energy".

• Hydropower:Sources: Water flowing over dams, tidal flows, and ocean waves.

• Production: Uses the kinetic energy of moving water. The world’s leading renewable energy source. China, Brazil, and the United States are the top producers.

• Environmental Impacts: Dams can cause habitat alteration and evaporation.

• Hydrogen:Potential: Clean energy source if produced without fossil fuels. Combines hydrogen and oxygen to produce electricity and water vapor in fuel cells.

• Challenges: Hydrogen is chemically locked in water and organic compounds and has a negative net energy when using fossil fuels to extract it. Fuel cells are costly.

IV. Energy Efficiency:

• Cogeneration (Combined Heat and Power): Produces two forms of energy from the same fuel source.

• Industry & Utilities: Improvements can be made by replacing energy-wasting electric motors, recycling materials, using LED lighting, metering energy use, and shutting down unused equipment.

• Vehicles: Switching to gasoline-electric hybrids, plug-in hybrids, electric vehicles, and hydrogen fuel cell vehicles, as well as using lightweight materials, can improve efficiency.

• Buildings: Green architecture, living roofs, superinsulation, and LEED standards can save energy and money.

V. Country-Specific Examples:

• Germany: Aims to obtain 60% of its energy from renewable resources by 2050, increase electricity efficiency by 50%, reduce CO2 emissions by 80-95%, and sharply reduce coal use. Employs a "feed-in-tariff" where utilities buy electricity from homeowners with solar cells.

• China, U.S., India: Largest consumers of coal.

• Russia, Saudi Arabia: Major oil producers.

• Norway: Highest percentage of its own electricity from hydroelectric power.

• France: Highest percentage of its own electricity from nuclear power.

• Iceland: Relies heavily on geothermal energy and aims to move its entire fleet to hydrogen fuel by 2060 (experimental).

VI. Energy Math Basics

• Power x Time = Energy (P x t = E)

• P = E/t (Power = Energy /time)

• P = V x I, where P = power, V = voltage, and I is the current in amps (A)

• American household voltage is 100 V (Air conditioners, electric stoves and dryers are 220 V).

• 1 kwh = 3600 kJ or 3.6 x 106 J

• % Change: Remember NOO =(New-Old)/Old x 100%

VII. Key Takeaways:

• Net Energy is Crucial: Evaluating the net energy yield is a primary factor in determining the long-term usefulness and sustainability of any energy resource.

• Fossil Fuels Dominance and Impacts: Conventional fossil fuels are abundant but have high environmental impacts.

• Renewable Energy Growth: Renewable energy sources are becoming increasingly viable and are essential for mitigating climate change and pollution.

• Efficiency Matters: Improving energy efficiency is crucial for reducing overall energy consumption and environmental impact.

Nonrenewable & Renewable Energy Study Guide

I. Key Concepts & Learning Objectives

• Energy Resources: Differentiate between renewable and nonrenewable energy sources, providing examples of each.

• Net Energy: Define net energy yield and net energy ratio. Explain how these concepts are used to evaluate the true energy return of various resources.

• Fossil Fuels: Identify the major types of fossil fuels (oil, natural gas, coal) and discuss their formation, extraction, advantages, and disadvantages.

• Oil & Natural Gas: Summarize the processes of horizontal drilling and hydraulic fracturing (hydrofracking). Discuss the benefits and environmental consequences of these technologies. Identify countries that are the largest producers and consumers of oil and natural gas.

• Coal: Outline the formation of coal and its different types (lignite, bituminous, anthracite). Assess the environmental impacts of coal mining and burning, including air and water pollution.

• Nuclear Power: Describe how nuclear fission reactors work. Discuss the nuclear fuel cycle, including uranium mining, enrichment, and waste disposal. Outline the environmental impacts of nuclear power, including the risk of accidents and the challenges of radioactive waste management.

• Energy Efficiency: Define energy efficiency and provide examples of how it can be improved in industries, transportation, and buildings.

• Renewable Energy Sources: Identify and describe the main types of renewable energy sources: solar (active, passive, photovoltaic), wind, geothermal, biomass, and hydropower. Discuss the advantages and disadvantages of each, considering environmental, economic, and social factors.

• Germany's Energy Transition: Summarize Germany's renewable energy goals and the feed-in-tariff system.

• Hydrogen Fuel: Discuss the potential of hydrogen as an energy source, including its advantages and limitations.

• Environmental Leadership: Define environmental leadership and provide examples of ways to implement sustainable practices.

• Energy Math: Use math equations for energy to make informed choices about energy consumption and efficiency.

II. Quiz

Answer each question in 2-3 sentences.

1. What are the three primary nonrenewable energy sources that constitute 90% of the world's commercial energy?

2. Explain the difference between net energy yield and net energy ratio.

3. What are the main environmental concerns associated with hydraulic fracturing (fracking)?

4. Describe the process of extracting kerogen from shale oil and the potential environmental impact.

5. What is bitumen, where is it found, and what are the environmental costs associated with its extraction?

6. Why is methane considered a more potent greenhouse gas than carbon dioxide, despite natural gas burning cleaner than other fossil fuels?

7. What are the primary environmental costs associated with the mining and burning of coal?

8. Briefly describe how a light-water nuclear fission reactor works.

9. What are the main challenges associated with safely storing radioactive nuclear waste?

10. What are the main components of Germany's renewable energy goals for 2050?

III. Quiz Answer Key

1. The three primary nonrenewable energy sources are oil, natural gas, and coal. These fossil fuels currently dominate the world's energy supply due to their established infrastructure and, in some cases, relatively high net energy yield. However, they contribute significantly to air pollution and climate change.

2. Net energy yield is the amount of high-quality energy available from a resource after subtracting the energy needed to make it available. Net energy ratio, also called energy returned on investment, is the energy obtained per unit energy used to obtain it; both are used to assess the overall energy efficiency of a resource.

3. Environmental concerns with fracking include the enormous water volumes required, the production of hazardous wastewater, the potential for earthquakes, and the risk of groundwater contamination. The exclusion of natural gas fracking from EPA regulations adds to these concerns.

4. Shale oil production involves mining, crushing, and heating shale rock to extract kerogen, which can then be distilled into oil. This process has a high environmental impact due to mining, water usage, and pollutant emissions.

5. Bitumen is a thick, sticky form of heavy oil found in oil sands (tar sands), particularly in Canada. Extracting it requires clear-cutting forests, strip-mining the land, and using large amounts of water, resulting in a low net energy yield and substantial pollution.

6. Methane, the primary component of natural gas, is a much more potent greenhouse gas than carbon dioxide, despite emitting less CO2 per unit of energy when burned. Leaks during drilling, production, and distribution contribute significantly to global warming.

7. The environmental costs of coal include severe land degradation from mining, air and water pollution from burning, and emissions of soot, carbon dioxide, mercury, and radioactive materials. The disposal of coal ash also presents a significant environmental challenge.

8. A light-water nuclear fission reactor works by using a controlled nuclear fission reaction to heat water, producing steam that spins a turbine connected to a generator. This process converts nuclear energy into electricity, with uranium fuel rods and control rods regulating the reaction.

9. Challenges in safely storing radioactive nuclear waste include finding a permanent, secure repository, dealing with the long storage times required (up to 240,000 years), and the enormous costs associated with plant decommissioning and waste management. The abandoned Yucca Mountain site plan highlights the difficulties.

10. Germany's renewable energy goals for 2050 include obtaining 60% of energy from renewable resources, increasing electricity efficiency by 50%, and reducing CO2 emissions by 80-95%. These goals also include sharply reducing the use of coal.

IV. Essay Questions

1. Discuss the advantages and disadvantages of hydraulic fracturing (fracking) as a method for extracting oil and natural gas. Consider environmental, economic, and social factors in your analysis.

2. Compare and contrast the environmental impacts of burning coal versus using nuclear power for electricity generation. What are the trade-offs associated with each energy source?

3. Evaluate the potential of renewable energy sources (solar, wind, geothermal, biomass, hydropower) to replace fossil fuels. What are the primary barriers to widespread adoption, and how can these be overcome?

4. Analyze the concept of net energy yield in the context of different energy resources. How does net energy influence the long-term viability and sustainability of these resources?

5. Examine the role of government policies and incentives in promoting the transition to a more sustainable energy future. Provide specific examples of successful and unsuccessful strategies.

V. Glossary of Key Terms

• Nonrenewable Resources: Resources that are finite and cannot be replenished at a rate comparable to their consumption. Examples include oil, natural gas, coal, and nuclear energy.

• Renewable Resources: Resources that can be replenished naturally over a relatively short period. Examples include solar, wind, hydropower, biomass, and geothermal energy.

• Net Energy Yield: The amount of high-quality energy available from a resource after subtracting the energy needed to make it available.

• Net Energy Ratio: The ratio of energy obtained from a resource to the energy used to obtain it; also called energy returned on investment.

• Horizontal Drilling: A drilling technique that allows access to oil and natural gas trapped between compressed layers of shale rock formations.

• Hydraulic Fracturing (Hydrofracking): A process that involves pumping water, sand, and chemicals into cracks in shale rock to release oil and natural gas.

• Shale Oil: Oil integrated within bodies of shale rock, extracted through mining, crushing, and heating.

• Oil Sands (Tar Sands): Extensive deposits containing bitumen, a thick form of heavy oil.

• Bitumen: A thick, sticky form of crude oil found in oil sands, requiring extensive processing for extraction.

• Natural Gas: Primarily methane, a fossil fuel with a medium net energy yield that burns cleaner than oil and coal.

• Liquefied Petroleum Gas (LPG): Natural gas stored in pressurized tanks for use in rural areas.

• Liquefied Natural Gas (LNG): Natural gas that has been converted to liquid form for ease of storage or transport.

• Coal: A solid fossil fuel formed from the remains of land plants and burned in power plants to generate electricity.

• Synfuels: Synthetic natural gas (SNG) or liquid fuels produced from coal gasification or liquefaction.

• Nuclear Fission: A nuclear reaction in which a heavy nucleus splits into smaller nuclei, releasing energy.

• Light-Water Reactor: A type of nuclear reactor that uses ordinary water as both a coolant and moderator.

• Control Rods: Rods made of neutron-absorbing material used in nuclear reactors to control the rate of fission.

• Nuclear Fuel Cycle: The processes involved in mining, processing, using, and disposing of nuclear fuel and waste.

• Energy Efficiency: Getting more useful work using less energy, reducing waste, and improving the use of energy resources.

• Cogeneration: Combined heat and power (CHP), the simultaneous production of two forms of energy from the same fuel source.

• Green Architecture: Designing buildings to minimize environmental impact, conserve energy, and use sustainable materials.

• Active Solar Heating System: A system that captures energy from the sun in a heat-absorbing fluid and uses pumps to circulate the heated fluid.

• Solar Thermal Systems: Systems that concentrate sunlight to boil water and produce steam to generate electricity.

• Photovoltaic (PV) Cells: Cells that convert solar energy directly into electric energy.

• Wind Turbine: A device that captures the kinetic energy of wind and converts it into electricity.

• Geothermal Energy: Heat stored in soil, underground rocks, and fluids in the earth's mantle, used for heating and electricity generation.

• Biomass: Plant materials and agricultural waste that can be burned for fuel.

• Biofuels: Fuels produced from biomass, such as ethanol and biodiesel.

• Hydropower: Electricity generated from the kinetic energy of moving water.

• Hydrogen Fuel Cell: A device that combines hydrogen and oxygen to produce electricity and water vapor.

• Feed-in-Tariff: Utilities must buy electricity from homeowners with solar cells and feed into electrical grid.

Here's an 8-question FAQ based on the provided sources, covering key themes and concepts:

What are the primary nonrenewable energy sources used globally, and what percentage of the world's commercial energy do they represent?

Approximately 90% of the commercial energy used worldwide comes from nonrenewable resources. The main nonrenewable sources are oil, natural gas, coal, and nuclear energy. While offering advantages like established infrastructure and (in some cases) high energy density, their extraction and use can lead to significant environmental consequences, including pollution and greenhouse gas emissions.

What is "net energy yield" and why is it important in evaluating energy resources?

Net energy yield refers to the amount of high-quality energy available from a resource after subtracting the high-quality energy needed to make that energy available. It's a crucial factor in assessing the long-term usefulness and economic viability of any energy resource. Resources with higher net energy yields are generally more desirable because they require less energy input to produce a usable amount of energy. The net energy ratio (or energy returned on investment) is the energy obtained per unit energy used to obtain it.

What is fracking and what are its advantages and disadvantages?

Hydraulic fracturing, or fracking, is a technique used to extract oil and natural gas trapped in shale rock formations. It involves pumping water, sand, and chemicals into cracks to release these resources. While fracking has increased access to previously inaccessible oil and natural gas, it poses several environmental risks, including the potential for water contamination from hazardous waste slurry and the possibility of induced earthquakes. It also requires significant volumes of water.

What are the major environmental concerns associated with using coal for energy?

The environmental costs of burning coal are substantial. Mining operations can severely degrade land and pollute water sources. Burning coal releases air pollutants such as soot, sulfur dioxide (SO2), particulate matter (PM), carbon monoxide (CO), and carbon dioxide (CO2), as well as trace amounts of mercury and radioactive materials. Scrubbers can remove some pollutants, but the process generates coal ash that must be safely stored. Coal combustion contributes to gray smog, acid rain, respiratory diseases, and mercury contamination.

What are the primary concerns associated with nuclear power, despite its low CO2 emissions during operation?

While nuclear power plants themselves don't emit CO2, the nuclear fuel cycle does. The major drawbacks are the high costs associated with construction and operation, the low net energy yield, the risk of accidents (like Fukushima and Chernobyl), the challenge of safely storing long-lived radioactive wastes, and the potential for nuclear technology to contribute to the proliferation of nuclear weapons. There is currently no permanent, secure repository for nuclear waste.

What is energy efficiency, and what are some strategies for improving it?

Energy efficiency involves getting more useful work out of a unit of energy. Examples include heating buildings, producing electricity, or driving more efficient cars. Strategies for improving energy efficiency include cogeneration (combined heat and power), replacing energy-wasting electric motors, recycling materials, using LED lighting, metering energy use, and adopting green building design principles like superinsulation and green roofs.

What are the main advantages and disadvantages of using solar energy, and what are some different methods of harnessing it?

Solar energy is renewable and produces minimal air or water pollution during operation. Different methods of harnessing solar energy include active solar heating systems (using a heat-absorbing fluid), solar thermal systems (concentrating sunlight to boil water for electricity), photovoltaic (PV) cells (converting sunlight directly into electricity), and solar cookers. PV cell production can involve toxins. Challenges include the intermittent nature of sunlight, the need for energy storage solutions, and the low net energy yields of some solar technologies.

What are the benefits and drawbacks of using biomass as a source of energy?

Biomass (plant materials and agricultural waste) is a potentially renewable resource that can be used for cooking, heating, electricity generation, and transportation fuels like ethanol. However, using biomass can lead to deforestation, soil degradation (due to fertilizer and pesticide use), and emissions of CO2, CO, and particulate matter. While biofuels can lessen dependence on oil, some biofuel crops (like corn for ethanol in the US) have low or even negative net energy yields and can increase greenhouse gas emissions compared to gasoline.

Okay, here is a timeline of the main events and a cast of characters related to energy resources, based on the provided sources.

Timeline of Main Events & Concepts

• Prehistoric Era: Formation of fossil fuels (coal, oil, natural gas) from the remains of plants and animals over millions of years.

• Industrial Revolution: Increased use of coal for power generation.

• 20th Century:Growing dependence on oil for transportation and other uses.

• Development of nuclear fission technology for electricity generation.

• Establishment of OPEC and its role in regulating global oil prices.

• Late 20th and Early 21st Century:Increasing awareness of the environmental impacts of fossil fuels (air and water pollution, CO2 emissions, climate change).

• Development of unconventional oil sources like oil shale and oil sands.

• Rise of natural gas production via hydraulic fracturing (fracking), with associated environmental concerns.

• Growing interest in renewable energy sources (solar, wind, hydropower, geothermal, biomass, hydrogen) and energy efficiency.

• 2005: Natural gas fracking excluded from EPA regulations.

• 2011: Fukushima Daiichi nuclear power plant accident in Japan.

• 2014: Nuclear reactors produced 19% of U.S. energy. The U.S. used 43% of its corn to make ethanol.

• 2015: Coal generated 40% of the world's electricity. 67 new nuclear reactors were under construction worldwide.

• 2020 (Projected): Peak in domestic production of tight oil from shale rock in the U.S., followed by decline.

• 2050 (Goal): Germany aims to obtain 60% of energy from renewable resources, increase electricity efficiency by 50%, and reduce CO2 emissions by 80-95%.

Cast of Characters

• OPEC (Organization of the Petroleum Exporting Countries): A group of 12 countries that play a role in regulating global oil prices by agreeing to increase or decrease production amounts.

• Mark Lynas: Climate change author, who stated that cutting global CO2 emissions in half between 2015 and 2040 and meeting energy needs would require building 12,000 nuclear power reactors.