Energy Resources and Consumption

renewable energy

energy that can be replenished naturally, if consumed at or near the rate of regeneration and reused

rate of regeneration

the rate at which a renewable energy resource is replenished

depletable renewable energies

energies that can run out if overused

example: biomass (wood, charcoal, ethanol)

nondepletable renewable energies

energies that can not run out, even if overused

examples: solar, wind, hydroelectric, geothermal

nonrenewable energy

energy that exists in fixed amounts on Earth and can’t be easily replaced or regenerated

examples: fossil fuels, nuclear

developed nations and energy consumption

typically use more energy on a per capita basis

developing nations and energy consumption

typically use more energy in total, as a result of higher populations

when these nations become more developed, there is an increased reliance on fossil fuels for energy

subsistence fuels

biomass that can be easily gathered or purchased; typically used by residents of less developed nations

availability

the number of discovered reserves of fossil fuels and the accessibility of the reserves

price

dictates fossil fuel usage, typically dependent on the availability of fossil fuels for consumption

government regulations

policies that can alter the prices of fossil fuels as a result of indirect actions, such as taxes, or discourage the usage of fossil fuels, such as rebates for using renewable resources

factors that affect energy source consumption

availability, price, and government regulations

wood

used in either its natural form or charcoal; more commonly used in developing nations because of its accessibility

peat

partially decomposed organic matter, which is found in wet, acidic ecosystems (like bogs and moors) that can be burned for fuel

lignite coal

the least energy dense type of coal; buried the least deep and thus experiences the least amount of pressure

bituminous coal

the medium-energy dense type of coal; buried at a medium deepness, and thus experiences a medium amount of pressure

anthracite coal

the most energy dense type of coal; buried the deepest, and thus experiences the most amount of pressure

natural gas

formed from the remains of plants and animals; composed of mostly methane and found atop oil deposits

cleanest fossil fuel, because it releases the fewest carbon dioxide and pollutants when burned

crude oil

formed from the remains of plants and animals; can be drilled via a well through overlying rock layers, but can also be removed from tar sands (combination of clay, sand, water, and bitumen)

fractional distillation

the process of converting crude oil into various different products by burning it in a furnace, where its vapor is then passed into a column that separates its hydrocarbons based on boiling points

allows for crude oil to be used into specific fuel types for specialized uses

examples: gasoline (cars), diesel (trucks), naphtha (plastic)

cogeneration

the ability for a fuel source to be used to generate both meaningful electricity and heat

a common solution to the inefficiencies of energy generation, as a result of losing energy of fuels as heat

main coal reserves

United States, Russia, China, Australia

main natural gas reserves

Russia, Iran, Qatar, United States, Saudi Arabia

main oil reserves

Venezuela, Saudi Arabia, Iran, Canada, Iraq

fossil fuel combustion

a chemical reaction between oxygen and fossil fuels that releases energy as carbon dioxide and water, with a byproduct being energy release

a component of the carbon cycle

energy production from fossil fuels

fossil fuels are burned to generate heat, which then heats up water and allows it to transform it into steam; the steam then travels to a turbine, which allows it to spin and generate electricity via a generator

environmental consequences of fracking

flowback water, or used fracking fluid, that flows back out can contaminate ground- and surface-water sources; releases volatile organic compounds; makes the soil more susceptible to sink holes as a result of increased permeability

nuclear fission

the process of firing a neutron into the nucleus of a radioactive element, like Uranium-235, forcing it to break apart and release lots of energy and more neutrons, which break more nuclei apart and continue the cycle

radioactivity

refers to the energy emitted via radiation by the nucleus of a radioactive isotope

nuclear power

fission of Uranium-235, which is stored in fuel rods and stored in water, releases a large amount of heat. The heat is utilized to turn water into steam, which spins a turbine that generates electricity via a generator

control rods

rods that are lowered into the reactor core, where nuclear fission occurs, and absorbs neutrons and slows down the reaction, preventing meltdown

water pump

brings in cool water, which not only is turned into steam but is also responsible for cooling the reactor down, preventing it from overheating

cooling tower

allows steam from the turbine to condense back into liquid and cool down before being reused, releasing water vapor into the atmosphere

environmental impact of nuclear power

doesn’t release air pollutants (sulfur dioxide, nitrous oxide, carbon dioxide, particulate matter, etc.) when electricity is generated

releases water vapor into the atmosphere, leading to thermal pollution, however water vapor stays in the atmosphere only briefly

thermal shock

a situation that arises as a result of hot water being released into surface waters, leading to decreased oxygen levels and thus suffocation in marine organisms

consequences of nuclear power plant accidents

radiation leaks lead to genetic mutations and cancer in nearby people and animals

environmental consequences of burning biomass

produces carbon dioxide, carbon monoxide, nitrogen oxides, and volatile organic compounds, which are all respiratory irritants, and can be worsened if burned indoors

overharvesting trees from forests can lead to deforestation, because biomass is a depletable renewable resource

ethanol

a biofuel that is used as a substitute for gasoline and doesn’t release new carbon dioxide into the atmosphere, however it has a low energy return once burned

environmental consequences of ethanol

utilizes large amounts of corn to be produced, and thus is commonly monocropped, which has many consequences (like topsoil erosion)

passive solar energy

energy that is obtained and utilized by absorbing or blocking heat from the sun, and without the use of mechanical or electrical equipment

examples: orienting buildings to let in the most light via southern facing windows and using the sun’s heat to cook food in a solar oven

active solar energy

the use of mechanical or electrical equipment to capture the sun’s heat or convert the light rays directly into electricity

photovoltaic cells (PV)

also called solar panels; capture light energy from the sun and transform it into electrical energy by causing the separation of charges between semiconductor layers

drawback of photovoltaic cells

have an issue with intermittency, since solar energy can only be obtained during the daytime or clear daylight conditions

concentrated solar thermal (CST)

mirrors that reflect the Sun’s rays onto a central water tower in order to heat water, which will produce steam to turn a turbine, which further generates electricity via a generator

drawbacks of concentrated solar thermal

can negatively harm desert ecosystems by causing habitat destruction, as a result of clearing land for the mirrors

rooftop solar

solar panels/PV cells that supply energy for a singular home or business

community solar

large-scale solar “farms,” or fields, that generate lots of electricity, but can cause habitat loss and fragmentation

benefits of solar energy

release no carbon emissions when generating electricity and will not run out

drawbacks to solar energy

semiconductor metals required for solar energy conversion must be mined and the technology can be expensive

hydroelectric energy

channels within dams allow for the moving water in the reservoirs to spin a turbine, which generates electricity

placing turbines into small, fast-moving rivers and allowing for the river to spin the turbine, generating electricity

tidal energy

the use of the Earth’s tides to spin a turbine, which generates electricity

dams

barriers in bodies of water that create reservoirs, or large artificial lakes, that operators can control, and thus allow more or less water through the channel in the dam, leading to an increase or decrease in electricity production

drawbacks of hydroelectric energy

can change or destroy habitats as a result of the construction of dams and the construction of power plants can also be economically taxing

benefits of hydroelectric energy

doesn’t generation air pollution or waste as a result of the generation of electricity; a reliable electricity source; and generates jobs as a result of maintenance and construction

fish ladders

series of elevated pools that allow migratory fish, like salmon, to continue to migrate upstream, around or over dams

geothermal energy

energy obtained by piping water into the ground, into a rock layer close to the mantle, which will be heated into steam and utilized to turn a turbine on the Earth’s surface, which in turn generates electricity

benefits of geothermal energy

far less carbon dioxide emissions, when compared to fossil fuels; potentially renewable, if water is piped back into the ground for reuse

drawbacks of geothermal energy

isn’t available in every geographic location, because the water may not become hot enough; hydrogen sulfide has the ability to be released and built up; and the initial cost is extremely expensive

hydrogen fuel cells

a renewable, alternative fuel source to fossil fuels; hydrogen and oxygen are combined to produced energy, specifically electricity, and water vapor (emission)

benefits of hydrogen fuel cells

produce no carbon dioxide emissions; can be stored in tanks to be transported and used at a further distance or later point in time

drawbacks of hydrogen fuel cells

energy, typically fossil fuel-based, must be used in order to obtain hydrogen gas from water; the technology involved is extremely expensive

wind energy

wind (kinetic energy) spins a turbine (mechanical energy), which generates electrical energy (electricity) via a turbine

drawbacks of wind energy

can kill migratory birds and bats that are hit by the blades of the turbine, and thus migration patterns will be disrupted

small-scale conservation

conserving energy around the home or an individual building

examples: lowering the thermostat to use less heat and AC, conserving water by planting native plants and water-efficient appliances, replace insulation to keep in heat better

large-scale conservation

conserving energy in larger areas or systems

examples: improving fuel economy standards, subsidizing electric and hybrid vehicles, increasing public transport, utilizing green building designs