Exam 1 study guide (Renewable Energy)
What is an oil or gas play?
-is a group of oil fields or prospects in the same region with the same geologic settings. -These are often quite large, like the Marcellus Shale which stretches across several states including most of Pennsylvania and West Virginia
Name two ways in which pollutants from fracking can leak into water resources
-Well casing leaks (casing is a pipe that is cemented in place to prevent leaks) -Leaks through fractured rock -Drilling site discharge or spills -Wastewater disposal -Transportation Spills
What is meant by renewable and non-renewable energy sources? Give some examples.
-Any resource that can naturally replenish in a reasonable amount of time. solar energy, wind energy, water, geothermal energy, and Organic materials like wood crop waste ("biomass") -Coal, oil, nuclear energy and natural gas are not renewable. These resources were formed through natural decomposition of buried organic materials over millions of years. This process is much too slow for fossil fuels to be considered renewable.
What is the greenhouse gas effect?
-CO2 and other greenhouse gasses traps heat that has been radiated from Earth & keeps it from being lost to space -Atmospheric particles transmit nearly all of the incoming shortwave radiation from the sun. However, the longwave radiation from the earth is absorbed very well (in particular by water vapor, CO2, and methane). -This role of the atmosphere in heating Earth by transmitting shortwave solar radiation but absorbing outgoing longwave radiation is called the greenhouse effect. -There is a natural greenhouse gas (GHG) effect because the atmosphere naturally contains CO2. This natural GHG effect keeps Earth's 33°C (59°F) warmer than it would be otherwise. An enhanced (anthropogenic) GHG effect is occurring because we add more greenhouse gases so that additional heat is retained by the atmosphere.
Briefly state some reasons why we are interested in using renewable energy sources
-Emission of greenhouse gases that cause climate change -Pollution of air, water, and soil; waste; health risks, other environmental impacts (e.g. destruction of ecosystems) -Energy production from fossil fuels needs water -Resource limitations of fossil fuels. As resources become more scarce, extraction costs rise. -Political instability of oil exporting nations -Fossil fuel prices are volatile (they go up and down unpredictably) -Growing world population and growing need for energy -Energy justice: not everyone has access to energy, and some people carry more of the environmental impacts than others -New technological opportunities: energy storage, long-distance trans-mission, international electricity trade, smart grids, community solar, microgrids, energy efficiency, electric cars. Also note that some of the lowest electricity costs are now achieved by renewables (wind, solar)
What is hydraulic fracturing ("fracking")?
-Hydraulic fracturing involves horizontal drilling and injection of a fracking fluid (water and chemicals) under high pressure -The injected fluid will create cracks through which gas can flow -The figure below compares vertical drilling for a conventional gas reservoir (right) and horizontal drilling (fracking) to extract Shale gas (left)
What is co-generation or combined heat and power?
-In a cogeneration or combined heat and power (CHP) plant, heat drives a turbine and the waste heat is used for space or water heating. -Typical cogeneration plants are powered by natural gas (here at Eden Hall!), biomass, biofuels or solid waste. -Efficiency is much higher than for regular coal plants, because regular coal plants do not use the waste heat resulting from burning the coal
Name two air pollutants emitted by burning coal for electricity generation
-Particulate matter (PM): tiny particles of soot (carbon matter), smoke and other small particles. Classified as Group 1 human carcinogens (cancer-causing agents) by the World Health Organization -Nitrogen oxides (NOx): gases that are composed of nitrogen and oxygen. NOx rritates respiratory tract and weakens immune defenses to respiratory infections. -Sulfur dioxide (SO2) contributes to formation of microscopic particles that can be inhaled deep into lungs and aggravate respiratory conditions such as asthma and chronic bronchitis -Mercury is toxic to the nervous system, the vapor has harmful effects on the digestive and immune systems, lungs and kidneys. Mercury can be transported long distances by wind
Why has there been a decline in employment in the coal industry?
1.Loss of profitability due to decline in demand and falling prices, which is in turn attributed to cheaper production in China (and to a lesser extent other countries) as well as increases in oil prices. 2.Also, mechanization has dramatically reduced the number of miners needed to produce a given quantity of coal
What are conventional and unconventional gas resources? What is the difference between resources and reserves?
Conventional: -reservoirs typically allow extracting the gas by simply drilling down vertically. -In these reservoirs the rock above the gas is generally very permeable: the tiny pores in the rock are close enough to each other and large enough that gas can flow easily ------------------------------------- Unconventional: -reservoirs cannot be drained economically with vertical drilling because they are trapped in rock structures with low permeability (small disconnected pores). -Here, horizontal drilling and "fracking" (hydraulic fracturing of the rock with a fluid under pressure) is needed to create a pathway for the gas to flow toward the surface -An example of unconventional gas is Shale gas. Shale gas is natural gas trapped within shale formations - fine-grained rock that is originally composed of mud
Describe some problems with nuclear energy generation.
Rising costs of nuclear power plants : -Nuclear plants have become very costly across construction, reprocessing, storage, decommissioning, fuel, security and research -A key problem is that the time required to build plants is increasing steadily. This is due to changing safety regulations and changing design, contract disputes, and shortages of parts and skilled labor -In addition operation and maintenance costs rise with plant age and fuel costs also grow every year -------------------------------------- Beyond rising costs there are other problems: -Waste storage -We need safe long-term storage option for high level nuclear waste (HLW). Finding a safe storage site and process is a major challenge. The amount of accumulated HLW is growing every year. -Due to the long half-life of nuclear elements (the time needed to reduce radioactivity by 50%), HLW will remain unsafe for tens of thousands of years. -Accident risks -Many nuclear plants are old and no longer meet Federal safety requirements -Earth quake and tsunami risks -Terrorist attack risks
What can we learn from studying the history of energy use?
-We have used energy for a very long time. -Being dependent on a particular energy source can become a serious problem - unless it is a renewable source that is always reliably available. -Producing energy is hard work and can cause serious pollution and health impacts. However, people have historically been very creative in finding new ways to produce and use energy.
What is the name of the Act that proposes to use funds from the Surface Mining Control and Reclamation Act to revitalize communities affected by the decline in mining jobs?
-The RECLAIM Act (Revitalizing the Economy of Coal Communities by Leveraging Local Activities and Investing More Act) was simultaneously introduced in the Senate and House of Representatives in March 2017 -The bill authorizes the use of funds generated by the Surface Mining Control and Reclamation Act of 1977 (SMCRA) to be invested in communities adversely affected by the cessation of mining operations -RECLAIM has not been sponsored till date
What are fossil fuels? Explain briefly and give examples.
-There are three types of fossil fuels used by society: coal, oil and natural gas. Fossil fuels are composed mainly of hydrocarbons (molecules containing primarily combinations of carbon and hydrogen) -Petroleum is a broad category of fossil fuels that includes crude oil. The gasoline that we use as fuel is derived from crude oil. -Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane.
List three forms of energy other than electricity
-Thermal energy or heat -Electricity -Light (radiant). Example: the sun's light. -Motion (kinetic). Example: molecular motion on a hot object. -Chemical (like fuel). Example: gasoline in car. -Nuclear energy Gravitational. Example: falling water in hydropower plant.
What is surface mining and what are some of the associated environmental impacts?
-Surface mining includes -Strip mining: mining minerals near the surface by first removing a strip of overlying soil -Open pit mining: extracting coal from an open pit -Mountain top removal: removing mountaintops so that we can extract the coal seams buried underneath ------------------------------------ Impacts: -It is highly invasive, in particular mountain top removal - profound changes in topography and disturbance or destruction of ecosystems such as forests (1.5 million acres of forest lost in Appalachia) -Hazardous wastes are often deposited on the ground or even in water ways -Reclaiming sites focuses on stabilizing rock, controlling erosion, replanting with quick-growing (often non-native) grasses. -Reclamation does not usually target rebuilding the landscape, restoring wastelands for agricultural production, cleaning waterways of hazardous compounds, reforestation, species restoration, or compensation of nearby landowners.
What is meant by clean coal?
-"Clean coal" is any technology deployed at a new or existing coal-fired power plant which will significantly reduce emissions of sulfur dioxide, nitrogen oxides, or CO2. -The most promising technologies are for removing sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter, and mercury. CO2 removal is much more difficult.
What is energy and what is power?
-A given amount of energy measures the quantity of the work that can be done (unit: Joule). -Power specifies how fast we can do this work. So, power is the amount of energy consumed per unit time. Common unit for power: Watt (J / second)
What is radioactive decay and how does a nuclear reactor work?
-some chemical elements have atoms that change. During this change they lose energy by emitting radiation in the form of a small particle (such as an alpha particle or beta particle). -is the division of an original nucleus (the small dense region at the center of an atom) into two smaller nuclei. The mass lost is emitted as heat (which we use to generate electricity) and harmful radiation like gamma rays. -------------------------- -Free neutrons hit uranium and plutonium atoms, causing the nucleus to split into two nuclei that are in total lighter. The "lost" mass is available as heat. -We use the heat to generate steam and drive a turbine