Enviro Unit 6
What are the most common forms (mixtures) of biodiesel?
B20 - 80% petroleum, 20% biodiesel
What is an environmental justice issue connected with trying to conserve energy?
Potential environmental injustice because subsidize things/ make them more of less expensive; don't allow lower income people to access these goods so not solve problem
What are ways that you can conserve energy at HOME?
Weatherize (insulate, seal gaps) (windows bad insulators); Turn thermostat down in winter, up in summer bc a lot of heat in winter or cold in summer makes a great temperature difference so heat energy releases to atmosphere; Reduce use of hot water (do laundry in cold water/ take shorter showers); Replace incandescent bulbs with compact fluorescents or LEDs
What is charcoal?
Wood that's already been burned but not burned to ash; Drier and lights quicker than wood w moisture
What is a generator?
contains a rotor w large electromagnets connected to large copper wires, creates electricity when spinning
How is peat harvested?
strip mining, let it dry out and it can be burned
What are commercial energy sources?
COMMERCIAL ENERGY SOURCES: An energy source that is bought and sold., Typical of developed nations (EX: Coal, Oil, & Natural Gas, Nuclear Fuel, Renewables, Occasionally wood, charcoal, animal waste)
Which country has the highest PER CAPITA energy consumption? Explain why.
Canada because each person uses a lot of energy
Which country has the highest TOTAL energy consumption? Explain why.
China has the highest total energy consumption because they have a lot of people and use fossil fuels
Explain in detail how a fracking operation works.
Drill down and then turns 90*, parallel to surface, through shale rock formation and then punch hole through well casing into rock layer; 3-4 months after initial drilling, fracking fluid pumped into well at high pressure so it cracks shale rock where trapped oil can escape; Fracking Fluid: water and chemicals (acid for clearing debris, friction-reducing compounds to make slickwater, disinfectant to reduce bacteria growth, sand+clay to prop open fissures for gas and oil to leak out even after pressure is released)
How does coal form?
First forms as peat and then a lot of time passes and pressure increases to become coal
Which areas are the best to place wind turbines? Why?
High up because faster wind speeds higher up; Wind turbines on land are typically installed in rural locations, away from buildings and population centers.; Wind off of mountain ranges, in plains areas, offshore (ocean winds), coastal
Explain in detail how oil and natural gas is extracted on land.
Pump hot steam into the ground to thin the oil; takes 81 trillion BTUs daily to warm ground to soften heavy oil which is otherwise too thick to recover
What is fusion and how is is a possible energy source in the future?
Smashing atoms together where they release a ton of energy; need to figure out how to do it on Earth
What are the current trends with renewables?
They're going up as people consider renewables more
What is a hydrocarbon?
This is what fossil fuel is; Made of carbon with varying amounts of hydrogen
How is the demographic transition connected to fossil fuel use?
Transition that developing countries make as they go from developing to developed status via industrialization; In general, what helps with transition is investments in energy that all countries are trading in a way that will benefit them; Developing nations are projected to start consuming more energy and use more fossil fuels
How is crude oil used in developed and developing countries?
Transportation, heating; Consume a lot in developed countries (especially bc plastics and products we buy and fertilizers)
How is coal used as a fuel?
burned to release energy
What are the three types of coal
lignite, bituminous, anthracite
What is the most recent percentage breakdown of each energy type used in the world?
15% renewables, 32% petroleum and other liquids, 22% natural gas, 26% coal, 5% nuclear energy
How does TOTAL energy consumption differ between developing and developed countries?
20% of the world's population live in developed nations and accounts for 70% of global annual energy consumption; Developed countries have more total energy consumption versus developing countries; As most countries become industrialized, demand for energy goes up; In developed countries, it's becoming more flatlined but still overconsuming
What is the projected percentage breakdown for 2050 of each energy type used in the world?
28% renewables, 27% petroleum and other liquids, 22% natural gas, 20% coal, 4% nuclear energy
What is the most recent percentage breakdown of each energy type used in the United States?
37% Petroleum, 29% natural gas, 14% coal, 9% nuclear electric power, 11% renewable energy; Of the 11% of renewable energy: 2% geothermal, 6% solar, 21% wind, 4% biomass waste, 21% biofuels, 19% wood, 25% hydroelectric
What is biodiesel and how is it produced?
A diesel substitute produced by extracting and chemically altering oil from plants; Ethanol takes starches and sugars for gasoline/ take oils instead of starches and sugars; With modifications, any diesel engine can run on straight vegetable oil (SVO)
What are ways that you can conserve energy through sustainable building design?
A sustainable building design incorporates: Proper solar orientation (In north, face house to South; In South, face house to North; bc sun directly), Smart landscaping (raingarden [better to conserve water], big tree for regulating heat), Insulated windows+walls+floors (double pane so reduce energy loss), Thermal mass (having something in home [ie stone floor] that absorbs a lot of energy and retains energy, warm stone floor via sun and emits heat in night when cold), Recycled building materials (construct new home with recycled materials instead of fresh wood);; Passive Solar Design: Using passive solar energy can lower your electricity bill without the need for pumps or other mechanical devices, building the house with windows along a south-facing wall in Northern hemisphere (north-facing in Southern hemisphere) which allows the Sun's rays to warm the house; Overhangs over windows built long so summer months, (when sun is high in sky) additional solar radiation doesn't enter house; in winter, sun is lower in sky so can get in straight through window; Heat absorbing floor/ thermal mass for winter cold, Benefit from summer and winter
What is a turbine?
A turbine is like a fan spinning-- connected to generator
What are the advantages and disadvantages of Concentrating solar thermal electricity generation?
ADVANTAGE: Can produce energy without fossil fuels; After initial investment, no cost to harvest energy DISADVANTAGE: Requires a large amount of land (may impact desert ecosystems), Unable to generate electricity at night
What are the advantages and disadvantages of solar water heating systems?
ADVANTAGE: Inexpensive to install; Easy to add onto system if already have on; After initial investment, no cost to harvest energy; Reduces cost for home heating and hot water DISADVANTAGE: Manufacturing materials requires high input of metals and water, Geographically limited (better in South), High initial cost
What are the advantages and disadvantages of nuclear energy
ADVANTAGE: Lack of carbon emissions (indirect emissions from mining), Ability to create huge amounts of energy, Doesn't depend on conditions around them (like wind turbines that need wind), One of the safest sources of energy, No deaths as a direct result of meltdowns, No air pollution, Reduces need to import oil DISADVANTAGE: Waste management, High total expense, Meltdown can force people out of homes and area around meltdown plant, Possibility of accidents, Thermal pollution
What are the advantages and disadvantages of hydroelectricity?
ADVANTAGE: Once built minimum amount of fossil fuel needed to operate; Zero air pollution, waste products, and CO2 emissions; Less expensive than nuclear and natural gas; Provides recreation- boating, swimming, fishing; Protects against seasonal flooding DISADVANTAGE: Large amounts of energy and resources needed for construction (fossil fuels and waste), Construction may require people to relocate, Interruption of natural water flow disturbs ecosystems both upstream and downstream, Siltation (build up of sediments behind dams so might make dam useless); Interferes with fish migration, and the associated equipment may kill fish
What are the advantages and disadvantages of passive solar energy collection?
ADVANTAGE: free energy coming in DISADVANTAGE: takes a long time
What are the advantages and disadvantages of using natural gas?
ADVANTAGES: Cleanest of the fuels, Exists as a component of petroleum in the ground as well as in gaseous deposits separate from petroleum, Contains 80-95% methane and 5-20% ethane, propane, and butane; Contains fewer impurities, Emits almost no sulfur dioxide or particulates, Emits only 60% as much carbon dioxide as coal DISADVANTAGES: Methane that escapes into the atmosphere is a potent greenhouse gas, Exploration for natural gas can contaminate groundwater
What are the advantages and disadvantages of crude oil?
ADVANTAGES: Convenient to transport and use, Relatively energy-dense, Cleaner-burning than coal, Oil is used in many other applications DISADVANTAGES: Releases CO2 into atmosphere, Possibility of leaks when extracted and transported, Runoff enters marine waterways; Releases sulfur, mercury, lead, and arsenic into the atmosphere when burned
What are the advantages and disadvantages of using coal?
ADVANTAGES: Energy-dense, Plentiful, Easy to exploit by surface mining, Needs little refining, Inexpensive, Easy to handle and transport; DISADVANTAGE: Contains impurities that are released into air when burned; metals like mercury, lead, and arsenic are found in coal; Combustion leads to increased levels air pollutants; Ash is left behind, leads to possible runoff; Carbon is released into the atmosphere
What are the advantages and disadvantages of hydrogen fuel cells?
ADVANTAGES: Fuel cells are 80% efficient; Water is the only byproduct DISADVANTAGES: Currently most commercially available hydrogen is produced by an energy-intensive process of burning natural gas (A separate option of electrolysis uses electricity); Hydrogen is explosive, so fuel cells can be very dangerous
What are the advantages and disadvantages of wind energy?
ADVANTAGES: It is a nondepletable and free energy resource; After manufacturing and installation, little energy input other than wind is required; Wind-generated electricity produces no pollution and no greenhouse gases; Wind farms can share the land with other uses. DISADVANTAGES: Most off-grid residential wind energy systems rely on batteries to store it (bc wind doesn't always blow); Wind turbines can be noisy and unattractive; NIMBY: Not In My Backyard (this killed the Cape Wind project); As many as 40,000 birds are killed by wind turbine blades in the United States each year; Bats can also be killed by wind turbines.
What are the advantages and disadvantages of photovoltaic systems?
ADVANTAGES: Non-depletable resource; After initial investment, no cost to harvest energy; Can connect to main grid so owner can sell excess energy back to electricity provider DISADVANTAGES: Manufacturing materials requires high input of metals and water; No plan in place to recycle solar panels; Geographically limited; Limited by weather (winter/ cloudy is bad); High initial cost; Storage of batteries required for off-grid systems; Most electricity use in evening, but solar panels not good at night so must store energy well
What are the advantages and disadvantages of geothermal energy?
ADVANTAGES: Nondepletable resource, Drilling technology is very well developed due to investment in petroleum drilling, After initial investment, little cost to harvest energy DISADVANTAGES: Expensive to find and drill sites for a power plant; Plants can emit some harmful gases, e.g. hydrogen sulfide, sulfur dioxide, and ammonia; Can cause thermal pollution of water
What are the advantages and disadvantages of using biofuel?
ADVANTAGES: Potentially renewable, Carbon neutral (some scientists dispute this), Significantly less air pollutants released (some scientists dispute this), Biodiesel can be produced with wood scraps or algae DISADVANTAGES: More expensive, Less miles per gallon, Potentially leads to long term corrosion of the engine, High amounts of waste, Relies on industrial agriculture
What are the advantages and disadvantages of using biomass?
ADVANTAGES: Potentially renewable; Carbon neutral; Reduced dependency on fossil fuels; If manure is burned, it removes pathogens from the surrounding ecosystem and reduces disease transmission DISADVANTAGES: Potentially renewable so net removal can make it unsustainable if you're taking more than it's replenishing, Can lead to deforestation, Large amounts of land needed, Produces variety of air pollutants because burning releases more than just carbon that are impurities
How does crude oil form?
AKA petroleum; liquid petroleum removed from the ground; Formed w natural gas by marine phytoplankton that get heat, pressure, and pushed under ground w plate tectonics; get transformed into oil (further heat to become gas); Less dense so floats up towards the surface through porous rocks, but can only reach surface if there is NOT an impermeable layer and can then get back into atmosphere; Most reservoirs we go for is trapped under shale (an impermeable layer), the reservoir is within the pore spaces of a rock it is NOT a cave
What is LIGNITE?
After millions of years and continued buried by overlying sediments and pushed down further by heat+pressure, it transforms into lignite coal; Most impure out of types of coal, lowest energy per square volume of coal, but more common
What is ethanol and how is it produced?
Alcohol made by converting starches and sugars from plant material into alcohol and carbon dioxide; US + Brazil produce the most in the world
What influences energy source choice?
Availability, price, government regulations (Government can subsidize energy to lower price and make it so consumer will go after it)
What are the units of measuring radioactivity?
Becquerel (Bq) measures the rate at which a sample of radioactive material decays; 1 Bq = decay of 1 atom or nucleus per second; Curie is a unit of measure for radiation; 1 curie = 37 billion decays per second
Where are the major deposits of COAL in the United States?
Big mining happens at rust belt (PN, OH, WV), but also other spots
What are the different types of solid biomass and how are they harvested?
Biomass is organic material made from leftovers broken down (extreme heat) and then refined into biofuels; wood, manure, clippings, etc
How is a biofuel different from solid biomass?
Biomass is solid and biofuel is liquid (kind of interchangeable)
What is the chemical equation for the combustion of fossil fuel?
Burning Hydrocarbons + Oxygen Gas generates Carbon Dioxide + Water + energy
What are ways that you can conserve energy by switching DEVICES?
Buy Energy Star devices and appliances (Devices designed to use less energy but cost more), Unplug when possible or use a power strip, Use a laptop rather than a desktop computer
Explain active solar energy collection.
Capture the energy of sunlight using advanced technologies that transform the energy into heat or electricity that's stored for later use; More expensive, greater output from sun
What are the three famous nuclear accidents?
Chernobyl (Soviet Union 1986), Fukushima (2011- caused by earthquake and tsunami that struck coastal plant), Three Mile Island (Pennsylvania 1979)
What are the current trends with coal?
Coal is on the decline, but still used in developing
What is liquified coal?
Coal that can be turned into liquid fuel (just need to know that it's a possibility); If the availability of petroleum is diminished, coal can be converted into liquid fuel (CTL, "coal to liquid")
Where are the major deposits of OIL and GAS in the world?
Come from marine phytoplankton settling down to bottom of ocean and then pushed underground via plate tectonics; A lot of this forms around coastal and tropical (sunlight) regions; If it's on land then there was ocean there before it was land; Convergent boundaries where there is marine snow pushed underneath
Explain in detail how coal is mined.
Continuous miner machine chops out rock to make access tunnels and feeds coal behind it into shuttle car (makes 5 tons of coal every minute); Longwall shearer smashes 50 tons of coal every minute; Conveyer takes coal into processing plant where it's graded according to size and then fed into a flotation tank because rock is heavier than coal, it can be removed while coal floats; Now coal is wet so put in spin dryer and then fed into tanks while contaminants removed as waste slurry and disposed of
Describe how a coal power station functions and generates electricity.
Converts energy from burning coal into electricity; Coal is grinded into powder, lit on fire in furnace lined w boiler tubes filled w water that is turned into steam via heat energy from burning coal; Steam move blades of turbine bc high pressure+speed; turbine blades connected to a generator that contains a rotor w large electromagnets connected to large copper wires; As generator rotor spins it form electrons/ electricity that's stepped up in voltage via transformers; Steam is condensed back into water and restart process; Wasted heat energy, exhaust gases (CO2) and other impurities, ash (waste) are toxic and lead to water pollution; Turbine+Condenser on edge of aquatic body to get water resource to cool steam leads to thermal pollution of water bodies
How does fracking pollute surrounding waterways (and especially groundwater)?
Disposing of used fracking water; Flow-back liquid comes up that has radioactive material, salts, heavy metals, and hydrocarbons that are usually disposed of on-site in deep wells w cement casing but can leak or water treatment facilities recycle it, but it increases contamination of radioactive material; Methane leaks out during fracking process is very potent than CO2
What is EROEI? How is it calculated?
EROEI: Energy Return on Energy Investment; EROEI is energy obtained from fuel/ energy invested to obtain fuel; The best form of energy to use depends on the particular purpose for which it is needed and it is possible to determine energy efficiency by calculating the energy return on energy investment (EROEI or EROI); The larger the value of EROI, the more efficient the fuel; We use EROEI because we want to get maximum energy and not waste it
How can we improve the electrical grid for society?
Electrical Grid is network of power lines connected to power stations throughout country/ world; Delivery of electricity can be problematic; Electricity for urban areas is typically generated in a remote location; US electrical distribution system ("the grid") is outdated and subject to overloads and outages, US spends over $100 billion every year to deal with overloads and outages, Between 5-10% of electricity is lost as it is transmitted across electrical lines; SOLUTION: Upgrade to a Smart Grid. A Smart Grid is an efficient, self-regulating electricity distribution network that accepts any source of electricity and distributes it automatically to end users; Implement devices that do work for you ie Nest (automatically adjusts temperature to fit need) or motion sensors trigger lights when in or out room or smart appliances to sync w home and know how they use energy
Explain about energy efficiency with regards to appliances and light bulbs.
Energy efficiency: constant technological advancement allows for products that consume less energy while producing the same desired outcome
Define the term "renewable".
Energy sources that can be replenished naturally, at or near the rate of consumption, and reused
Explain in detail how a tidal system can generate electricity.
Energy that comes from the movement of water driven by the gravitational pull of the Moon (and Sun); Put turbines underwater (where there is significant tidal flow); As the tide comes in and goes out, it spins turbine and runs generator; Does not have the potential to become a major energy source; In most places, the difference between high and low tide is not great enough to provide significant kinetic energy; takes a lot of time
What is hydraulic fracturing?
Extract natural gas, long vertical pole (well bore) drills down 3000 meters where it can do horizontal drilling
Explain in detail how oil and natural gas is extracted on the ocean.
Find reservoirs under water, get drilling rig, drill bit cuts into soft ground ("spudding in" the well), put drill pipe into place so well doesn't collapse while drill bit digs deeper down, put manmade 'mud' from surface down to drill bit to keep lubricated + equalize pressure + prevent outside things flowing in, bit is pulled out of hole and smaller pipe or casing run down into pipe and permanently sealed w cement and mud (separated by cementing plug) btw small pipe and big pipe, extend another pipe further, repeating the process and then install Blowout Preventer at seafloor to protect rig and environment from oil+gas flow if weight of mud is too low
What are examples of nonrenewable energy resources?
Fossil fuels (coal, oil, natural gas): biological material fossilized millions of years ago by being; Nuclear Fuel: Derived from radioactive materials that give off energy, A rock that contains uranium is radioactive that is decaying naturally overtime and releasing heat energy, take lots of uranium put into a nuclear plant and controlled to make heat energy for electricity
Why would developing countries opt to use fossil fuels rather than renewable energy sources?
Fossil fuels are what's used by most countries and is traded with other countries
Explain in detail how nuclear plant generates electricity`.
Fuel (usually uranium) is mined and formed into pellets that are place in rods within the reactor; Uranium undergo controlled chain reaction to produce heat; The heat energy turns the water around the reactor into steam which turns the turbine and generates electricity; Later, steam condensed back into water to reuse
What are the most common forms (mixtures) of ethanol?
Gasohol is 10% ethanol and 90% gasoline; E85 is 85% ethanol and 15% gasoline (Flex-fuel vehicles can run on this or traditional gasoline, More common in the midwestern states)
Explain in detail how how a geothermal energy is harvested to generate electricity.
Geothermal energy is heat that comes from the natural radioactive decay of elements deep within Earth NOT solar; US, China, and Iceland, all of which have substantial geothermal resources, are the largest geothermal energy producers (depends on plate tectonics; good at divergent boundaries where it releases heat energy or volcanoes); Harvest heat from Earth's crust bc it warms water in underground reservoirs; reaches Earth's surface when it's hot enough to be hot water or steam (usually happens where plates shift); Drill into ground to get water down closer to that hotter area; let water into steam which spins turbine and generator and then sent back underground
What is ANTHRACITE?
Give bituminous more time and pressure, it becomes anthracite and gets continuously squished and impurities are pushed out and become more concentrated; Most energy per unit volume of all coals
What is BITUMINOUS COAL?
Give lignite more time and pressure- hundreds or millions of years-- gets continuously squished and impurities are pushed out and become more concentrated
How do green roofs help conserve energy?
Green building design for water management and thermal mass; In summer months, evapotranspiration from vegetation reduce amount of cooling in home; In winter, soil acts as hat and helps retain heat
What is a ground source heat pump? Why is it not actually geothermal energy?
Ground source heat pumps transfer heat from the ground into a building; Although the heat tapped by ground source heat pumps is often informally referred to as "geothermal," it comes from solar energy that has heated the surrounding land
What is half life?
Half-life is amount of time it takes for a sample of radioactive material to decay into half of its existing radioactive
How is natural gas used as a fuel?
Heating and cooking and making nitrogen fertilizers
Explain in detail how hydrogen fuel cells can generate electricity.
Hydrogen fuel cells have many potential applications; Sort of like a battery; generates electricity from abundance of hydrogen and oxygen; it's waste is water; Hydrogen gas is fed into one side of fuel cell from external source and air (contains oxygen gas) is fed in other side; Protons from hydrogen passes through membrane of fuel cell, with electrons flowing around membrane, and then proton and electron recombine on other side of membrane, generating an electric current; Hydrogen combines with oxygen on other side and reacts to form water (H2O); Hydrogen is clean energy bc it stores energy (but getting hydrogen [ie splitting it from water] takes energy); In a fuel cell vehicle, hydrogen is the fuel that reacts with oxygen to provide electricity to run the motor.
What are oil sands (also called tar sands)?
If crude oil isn't stopped by impermeable layer, it can reach surface and become in contact with modern sediments and microbes which interact and degrade that oil; Bitumen is a degraded petroleum that forms when petroleum migrates to the surface of the Earth and is modified by bacteria; Petroleum is then very mixed with sediment and bitumen so it becomes slow flowing, viscous deposits of bitumen mixed with sand, water, and clay; We extract it (easy bc on surface so strip mine), but a lot of processing/ energy costs; Worst form of fossil fuel bc even though they don't release as much CO2 as coal when burned they need a lot of energy for processing
What is the half life of uranium-235?
If you have a kg, it takes 700,000,000 years; And then another 700 mill for it decay another half (exponential, divide by 2)
Explain control rods
Inside nuclear core, fuel rods of uranium; Control rods inside fuel rods to control reaction; Core is surrounded by water; Core and steam generator are sealed within a containment structure to prevent leaking radiation and harming humans; Fuel rods are cylindrical tubes that enclose nuclear fuel within a nuclear reactor; Control rods can be inserted in between fuel rods to absorb excess neutrons to slow or stop the fission reaction
Is peat modern carbon or fossil carbon? Explain.
It's kind of both. The carbon has been buried under the ground for hundreds of years so technically fossil, but was more readily in the atmosphere
What are the current trends with nuclear energy?
It's relatively flat and increasing super slowly
How does peat form?
Leaf matter + sticks fall to bottom of forest floor or lake; as long as there are cold temperatures or low oxygen then little to no decomposition occurring; Over time, as the matter builds up, it crushes itself into a solid form of organic carbon that can be extracted and burned; Need sediment layers to form on top and crush it as lake dries up in aquatic succession
What is the purpose of a levee? A dike?
Levees and dikes are built to prevent flooding; Levees are enlarged banks built up on either side of a river that occur naturally; Humans build them higher for protection; Dikes are structures built to prevent ocean water from flooding adjacent lands (sea walls)
What happened to the town of Enfield, Massachusetts?
Location of Enfield Massachusetts was decided to be good valley for Quabbin reservoir so everyone living there was forced out, everything was ripped out, and reservoir filled it in
What is modern carbon vs fossil carbon?
MODERN CARBON: Carbon in biomass that was recently in the atmosphere; It was recently CO2 in the atmosphere and then pulled into a plant and then turned into biomass (ie wood); Does not change atmospheric CO2 so it's carbon neutral because that CO2 was recently just in the atmosphere FOSSIL CARBON: Carbon stored in fossil fuels for millions of years (coal, natural gas, crude oil); This will increase CO2 in atmosphere because it was in deep storage of carbon cycle and by extracting this, it adds to the CO2 count
How does natural gas form?
Marine organisms fall to the ocean floor and build up and get pushed down; In lack of oxygen they become kerogen; heat and pressure changes the kerogen into oil or gas (over millions of years); Constant pressure and movements of Earth's crust squeezes oil and natural gas up through pores and spaces in rocks and some get to surface but others get stopped by an impermeable layer where it forms a reservoir underground
What is uranium-235?
Most common nuclear fuel is uranium-235; Electricity generation from nuclear fuel uses uranium-235 as a fuel source; decays into thorium
What are SOLAR WATER HEATING SYSTEMS? Explain how the work.
Mostly used for heating pools or generate hot water; Solar collector in which water cycles through it w pipes so pump cold water in and sun heats up water and then bring hot water down to hot water tank to be stored for later use
What is the controversy surrounding disposing nuclear waste?
Need to bury it in a secure location where people can't access it for protection of humans, but also national security; High level wastes-- no agreed upon storage so just leave them on site
What is the difference between a potentially renewable resource and a non depletable resource?
Nondepletable can never go away or be used up, while potentially renewable can be indefinite as long as we use it properly
What states have the least amount of solar energy (kWh/m2/day)? Why?
Northeastern states, Michigan, Washington, and Alaska; Gets low sunlight bc weather (temperate rainforest)
Explain the process of nuclear fission.
Nuclear reactors use nuclear fission; Fission is a nuclear reaction in which a neutron strikes a relatively large atomic nucleus which then splits into two or more parts, releasing additional neutrons and energy in the form of heat.; We want heat energy to make water into steam and pass it by turbine to generate electricity
How is wood used in developed and developing countries?
Often used in developing countries because it is easily accessible (rural areas); Used for heating homes, cooking, boiling water, everything
What are the current trends with petroleum and natural gas?
Oil and natural gas is increasing as most of the world is going through the demographic transition; 80% of the energy used in the world is fossil fuels
What are examples of renewable energy resources?
POTENTIALLY RENEWABLE: An energy source that can be regenerated indefinitely as long as it is not over harvested; Fall under MSY category; Can be burned to get heat energy and use it, but might run out of wood/ forest and might not have that resource; Biofuels from monocropped corn that we can turn into gas or fuel that we can burn NONDEPLETABLe: An energy source that cannot be used up; Can never be used up; The wind, sun, hydroelectricity from water flow, wave/ tide energy, geothermal
What are the pros and cons of man-made levees?
PROS: Protect people near rivers from flood events CONS: Diverts floodwaters from one location to another; If high precipitation it now goes downstream and floods another group; OR we make levies all along it and it shoots into the ocean; Large floods or storms can breach a levee, either flowing over the top of destroying a portion of it; No sediment replenishment in the floodplain; All sediment shoots into ocean
What are the overall pros and cons of using solar energy?
PROS: Renewable energy source, non-depletable, Reduce electricity bills, Low maintenance cost, Overall use less fossil fuel CONS: Storage is expensive, Initial building is expensive, Can only obtain energy during the day so must find a way to store it for use when energy is used the most at night, Depends on geography (best in the South or where there is more direct sunlight), Depends on weather and other irregular factors
Explain how solar energy is converted to electrical energy in a photovoltaic cell.
Photovoltaic solar cells capture energy from sunlight and convert it directly into electricity; Solar energy has photons that radiate and collide with semiconductor of solar panel; Panel made up of multiple individual cells w a positive and negative layer, creating an electric field; When photons hit panel, they knock out electrons in semiconductor material which create electric current; These currents are harnessed by wires connected to positive and negative cell; Advantage: produce clean energy, no emissions, no moving parts, doesn't make noise, doesn't need water or fossil fuel
What happened to New Orleans, and specifically the 9th Ward, during Hurricane Katrina?
Poorest district in city because it's in flood plain, lowest lying area, most susceptible to flooding (so home prices have urban blight); Hurricane Katrina made its way through gulf of mexico and hit new orleans dead on and slammed into coast forcing water up the river systems and up into lake that's above new orleans and the excess water overpowered the levees and overflowed
What are ways that GOVERNMENT can help conserve energy?
Providing public transportation; Taxing fossil fuel use but NOT using this tax money to make wider highways or promote urban sprawl; Offering rebates or tax credits for renovating homes or investing in energy saving technologies (if you have electric car or alternative energy improvements, might be able to get tax credits); Mandating standards for various companies
How does restricting the flow of the Mississippi River using levees cause severe land loss in coastal Louisiana?
River used to flood regularly and deliver silt to the land to keep it above water, but walls around river to keep it from flooding so no delivery of silt; No replenishment of sediment and river forced to flow in one way, so ocean gets all the sediment and erodes land
What are subsistence energy sources?
SUBSISTENCE ENERGY SOURCES: An energy source gathered by individuals for their own immediate needs, Typical of developing nations in rural areas (EX: Straw, Sticks, Wood, Animal waste)
Where are the major deposits of SHALE OIL and GAS in the world?
Shale: location where natural gas and some oil can seep into an impermeable shale layer via small cracks in rock-- what we extract when we are fracking; A lot exists in continental US (this is why US oil is booming)
What are different ways that solar energy can be collected actively?
Solar Water Heating Systems (heat pools); Photovoltaic (PV) Systems (solar panels); Concentrating Solar Thermal Energy Generation (CST; large conical systems in desert to direct energy inward)
What is biomass?
Solid biomass: anything modern carbon, recently in atmosphere and taken by plants and now used for energy
What states have the greatest amount of solar energy (kWh/m2/day)? Why?
Southwestern parts and Hawaii because the biome, cloud formation, weather, dry air; Upwards of 6.5-7 kWh of energy striking every square meter everyday
Explain passive solar energy collection.
Taking advantage of solar radiation without complex technology; Typically no extra equipment needed; Primarily used to heat homes, Can be used to cook food, Cost is relatively low; EX: positioning windows on south-facing walls, using dark materials to absorb more solar energy; Developing nations can harvest forests for wood and other biomass--- but instead heat/ cook food here easily
Where are the major deposits of COAL in the world?
Tend to form in forested, temperate forested regions; Form in places that are cold or with low oxygen conditions
How does plate tectonics play a role in the global distribution of fossil fuels and mineral ores?
The fossil fuel created is based off of the area and conditions so if plate tectonics shift, the fossil fuels and mineral ores might exist in an area where conditions don't seem to be right for the creation of this form of energy
Explain in detail how how a water impoundment system generates electricity.
The kinetic energy of water can generate electricity; The amount of hydroelectricity depends on the flow rate, the vertical distance water falls, or both; Water flows from higher elevation to lower elevation and use motion to spin turbines and generators; Impoundment system = dams; Store water in reservoir and when it is released it flows through dam and spins a turbine, turning a generator that produces electricity; Most common method of hydroelectricity generation; flow rate is controlled by opening and closing gates
What are the cost and storage issues associated with renewable energy technology?
The major impediments to widespread use of wind, solar, and tidal energy (renewables with the least environmental impact) are cost and the limitations of energy storage technology; Cost of renewables have been falling; Energy storage technologies are constantly improving, BUT expensive need to invest in it
How does a fish ladder help migrating fish? How can it be a problem?
They aim to reserve fish passage; Fish enter through vertical slots that lead into a series of small pools that create gentle flowing currents and contain rocks that provide shelter for smaller fish; The fishway creates a gradual ramp of water for fish to travel across the dam; with pools where tired fish can rest; This can be a problem because predators can have an easier time tracking when they're migrating so more fish get killed
Why do rivers tend to meander over time?
They carve out areas in mountain rock; On plains, rivers flow through soft soil that can be shifted into new banks and shapes by the river, Disturbance time allows changes in river flow; i.e animal burrows hole in river bank and the soil erodes, slowing river, dropping sediment to make it shallower and shallower until the water doesn't flow over it anymore; the force of the river going around this curve has a lot of momentum slamming it into the other side of the river bank which shapes it curvier
What are ways that ENERGY COMPANIES can help conserve energy?
Tiered rate systems (if you use less energy, you'll be charged a lower rate; if you use more, you're charged higher rate); Better access to your home energy data so homeowner/ you can better analyze what they can do to save energy
Explain how uranium is mined.
Tunnel underground; Uranium ore lies beneath water saturated sandstone; Drill bits punch into the rockface; First pipes pull heat out of the ground to freeze it around the ore; Make small initial pilot hole to guide larger equipment and then widen hole; Broken ore falls into extraction chamber where tram picks up the rock (keep humans from radiation and falling rock) and delivers uranium to scanner to decide percentage of it then brings it to a shoot where hammer breaks into bits and then smushes it into powder and add water into slurry; Slurry transported to mill and sucked up
Define the term "nonrenewable".
Types of energy sources that exist in a finite supply; When they run out, they are gone and can never be used again
What is the trend of wind production in the United States?
US generates more electricity from wind energy than any other country; However, some relatively small countries generate a much higher percentage of their total electricity from wind.
Why did humans originally want to settle in floodplains? Why are we still living in these areas today?
Under heavy precipitation or seasonal snow pack melt, rivers will overflow banks and create flood plains; this is where humans set up bc fertile soil for agriculture and river transport/ trade, but seasonal flooding so move in and out; Now, we have cities along river and so we can't have it flood anymore so we create dams and levees (larger banks, sediments build up holding river back) so we can control the flow
What are CONCENTRATING SOLAR THERMAL ELECTRICITY GENERATION? Explain how the work.
Uses lenses or mirrors and tracking systems to focus sunlight falling on a large area into a small beam where it is collected in the center (like solar oven) and turned into electricity (like turbine/ generator)
How is coal used in developed and developing countries?
Vital for developing countries to become developed countries
What are ways that you can conserve energy via TRANSPORTATION?
Walk or ride a bike, Take public transportation, Carpool, Consolidate trips (do multiple errands in one trip)
How can smart technology help us conserve energy?
Want to use energy more efficiency by replacing appliances with devices intended to conserve energy; Energy Star appliances, but cost more money; Standards and condescents lightbulbs being replaced by CFL (compact fluorescent lamp) and LED (produce same amount of lumens/ light, but fewer watts/ electricity used and last longer)
How is radioactive waste disposed?
Waste is nuclear fuel that can no longer produce enough heat to be useful in a power plant but continues to emit radioactivity; We bury it in secure location bc don't want people getting their hands on it for national security reasons; High-level waste (Used fuel rods)-- haven't agreed on where to store it, currently stored on-site of plants; Low-level waste (Contaminated protective clothing, etc.); Uranium mine tailings; Containment (placement of exhausted fuel into safe containers where it will remain for a very long time); Reprocessing (More expensive, Treats the waste so it can be used in a reactor again, Not practiced in US bc lack of facilities)
Explain in detail how a run-of-the-river system generates electricity.
Water is retained behind a low dam (or no dam at all) and runs through a channel before returning to the river; Channels portion of river through canal into a generator and turbine; Uses natural run of the river, doesn't require dam; Relatively little flooding occurs upstream; Seasonal changes to the river are not disrupted; Extremely dependent on the flow of the river; System generates little to no electricity in periods of low precipitation
What are other methods in which moving water can be converted into electricity?
Wave energy: Use flow of water in and out on edges where waves start to crash in; Pumped-Storage hydropower: provides peak-load supply, harnessing water which is cycled between a lower and upper reservoir by pumps, use surplus energy from the system at times of low demand, When electricity demand is high, water is released back to the lower reservoir through turbines to produce electricity.
What is peak demand? Why is it important to conserve energy during this time?
When most people are trying to access energy (mostly electricity); Most people try to get lowest solar energy at night, and high energy during day; In Summer, peak use of energy happens after school/ work day when everybody gets home and uses devices/ air conditioning; In Winter, peak in morning and evening and dip at midday bc not using as much electricity, more oil and natural gas to heat homes; We're trying to find way to reduce energy use at those peaks
Explain in detail how a wind turbine can generate electricity.
Wind energy is the most rapidly growing source of electricity; Wind turbine blade has shape so as wind passes around it, there's higher pressure on one side and lower pressure on the other side which allows the blade to spin; There's a weather vane on top connected to a computer that keeps the turbine facing the way with the most wind to capture max energy; Blades attached to shaft inside turbine which spins 18 revolutions per minute, connected to series of gears (gearbox) that increases rotation to 1800 revolutions per minute which is connected to the generator
How can an activity be considered carbon neutral?
any activity that does not change atmospheric CO2
What are other ways that fracking impact the environment?
increased seismic activity in fracking locations
What is cogeneration?
occurs when a fuel source is used to generate both heat and electricity; Take waste heat to make steam and use steam and chilled water to heat and cool areas
What is radioactivity?
occurs when the nucleus of a radioactive isotope loses energy by emitting radiation; Nucleus of chemical elements aren't fixed and can change spontaneously from one element to another; Proton in nucleus spontaneously changed into a neutron and stayed behind where the electron (beta particle) shoots out; Also shoot out alpha particle (8000 times larger than beta particle), made of 2 neutrons and 2 protons-- helium nucleus
How does graphing energy consumption in the United States from 1850 to present reveal a demographic transition?
reveals a nation undergoing industrialization by increase in energy uses; Before industrial revolution, form of energy was wood; After industrial revolution, coal helped through transition; Modern times: fossil fuels (oil, natural gas) high
