Pearson Environmental Science: Chapter 17

Energy

The ability to do work or cause a change

Kinetic energy

The energy produced by motion

Potential energy

The energy that an object has because of its position or shape

Law of conservation of energy

Energy cannot be created or destroyed, only transformed

Energy transformations in a thermal power plant

Primary energy source (coal, natural gas) is burned, boils water that turns to steam, the steam turns a turbine, the turbine is connected to a generator that transforms the motion into electricity

secondary energy source

A form of energy such as electricity that must be produced from a primary energy source such as coal or radioactive material.

Generator

A device used to convert mechanical energy into electrical energy. Magnets surrounding a coil of wire.

Battery

A device that converts chemical energy to electrical energy - anode, cathode, electrolyte

Benefit of batteries

mobility - ability to go off grid

off the grid

not connected to public utilities/powerlines

chemical energy

Energy stored in chemical bonds - coal, natural gas, food

electrical grid

connects power plants together and links them with end users of electricity

Combustion

Burning; the chemical reaction when fuel combines rapidly with oxygen

Energy efficiency

An expression of how much of the energy put into a system actually does useful work

Renewable energy

An energy resource that is readily available or that can be replaced in a relatively short time; includes wind, moving water, the sun's heat, and wood

Nonrenewable energy

An energy resource that cannot be replaced in a relatively short time; includes fossil fuels and nuclear energy

Electricity

The energy produced by the flow and interaction of electrons

Strip/surface mining

A type of mining in which layers of surface soil and rock are removed within 200ft from the surface from large areas to expose the resource

Subsurface mining

A type of mining in which vertical shafts are dug deep into the ground and networks of horizontal tunnels are dug or blasted out to follow deposits of a resource

mountaintop removal mining

Type of surface mining that uses explosives, massive power shovels, and large machines called draglines to remove the top of a mountain and expose seams of coal underneath a mountain.

coal

Fossil fuel created from remains of plants that lived and died 100-400 million years ago - through HEAT, PRESSURE, AND TIME - reserves that have been buried longer are more energy dense

main use for coal

generating electricity

coal benefits

Cheap, abundant, little refining, easy to transport

coal cons

nonrenewable; mining dangers for workers and environment - acid mine drainage; combustion - carbon emissions and air pollutants that lead to acid rain, smog, and mercury exposure

natural gas

Fossil fuel created from the remains of tiny sea plants and animals that died and were buried on the ocean floor over hundreds of millions years ago - sedimentary rock - HEAT, PRESSURE, TIME

hydraulic fracturing

Drill into shale rock with a mix of water, chemicals, and sand

Pressurized streams cracks shale open (mini earthquakes and methane can escape)

Pull natural gas and wastewater from rock

Natural gas main uses

Electricity, heating, raw material, transportation fuel

natural gas pros

Cheap, domestic energy, versatile - can use for many forms of energy and as a raw material, burns “cleaner” than the other fossil fuels

natural gas cons

Nonrenewable

Fracking - habitat destruction, uses lots of water, mini earthquakes, waste water can contaminate local sources, methane escapes during the process

Combustion - greenhouse gas emissions released - carbon dioxide and methane

Drilling for petroleum

Use rig - apply pressure to release oil from limestone - force oil upwards (like squeezing a sponge)

offshore drilling

Much more costly - close to shore on stilts, far offshore floating - to extract petroleum

Petroleum Pros

Transportation infrastructure set up for gasoline vehicles, convenient products can be made (petrochemicals - plastics)

Petroleum Cons

reserves depleted soon, pollution during drilling, transport and refining, burning makes CO2

Exxon Valdez Oil Spill

Major tanker accident in Alaska in 1989, that resulted in a major oil spill in Prince William Sound, AK when ship hit a reef

Deepwater Horizon Oil Spill

Offshore platform exploded, causing history's largest accidental marine oil spill as of mid-2010 - Gulf of Mexico - 87 days before capping spill

Petroleum

A liquid fossil fuel made up mostly of hydrocarbons - formed from the remains of tiny sea animals and plants buried hundreds of millions of years ago on the ocean floor; the primary source of gasoline

Petrochemical

A chemical compound derived from oil that is used to make plastics, detergents, and other products

Acid drainage

When coal ore is exposed - acid and the metals it causes to leach from rock that seep into groundwater or enter streams and lakes as runoff

acid rain

Rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water.

Energy conservation

Reducing energy use to prolong the supply of fossil fuels

Nuclear energy

The energy that holds protons and neutrons together in the nucleus of an atom

Nuclear fission

The conversion of the energy within an atom's nucleus to usable thermal energy by splitting apart atomic nuclei

Nuclear reactor

A facility within a nuclear power plant that generates electricity through controlled nuclear fission

Meltdown

The accidental melting of the uranium fuel rods inside the core of a nuclear reactor, causing the release of radiation

Nuclear waste

The radioactive material left over from the production of energy and other processes in a nuclear power plant

How is nuclear fuel made?

Uranium is mined, milled to separate from rock, concentrated into yellow cake, enriched, fabricated into pellets and stored in fuel rods

Nuclear main use

electricity

Nuclear Energy Pros

Produces a lot of energy; does not cause pollution; safe for workers

nuclear energy cons

Expensive to build facilities

Nuclear waste is a problem - where to store - still radioactive

Mining for uranium destroys habitats

Catastrophic events are possible

3 mile island

Nuclear reactor accident in PA 1979, partial meltdown, caused U.S. to strengthen nuclear regulatory laws

Chernobyl

Nuclear power plant in Ukraine that had an explosion in 1986 & released radioactive materials into the air - 119,000 evacuated, 30 died immediately, thyroid cancer

Fukushima

Nuclear power plant in Japan, 2011 - Series of equipment failures, after tsunami caused by earthquake - nuclear meltdown (core was damaged due to overheating)

How would the ability to store electricity change the way it is produced?

We could feed electricity into storage and use it when we need it - this makes renewables like solar and wind better options - we can generate power where it is cheapest and most abundant (super sunny or windy)

How will energy demands change as people in countries like India and China continue to move into the middle class?

Their demands for energy will greatly increase, exceeding those of the US and Europe combined.

What is meant by 'energy poverty'?

Living without available, affordable, reliable, and safe energy

Why is it a challenge to expand the grid to rural areas?

It’s expensive to build power lines

What 3 things are now affordable and necessary to be off grid?

Small solar panels - energy source

Batteries - energy storage

Efficient electronics - so energy output is less

What are the benefits of efficiency?

Reduces emissions

Extends energy supplies

Increases energy security

Saves money - fewer resources used and less infrastructure needs to be built

What are 3 big challenges of efficiency?

Hard to incentivise suppliers to sell less energy

Retrofits can be costly (adding new technology for efficiency improvements)

Changing our habits to use less energy - cultural

Describe ONE way to conserve energy

Conserve energy: includes any behavior that results in the use of less energy: shut off lights and unplug appliances when not in use, turn down the thermostat in your home when you leave, pull down blinds to prevent light from heating the indoors, use cold water for washing clothes, drive your car in a way that saves gas (less quick acceleration and revving the engine - combine errands for one trip, keep tires inflated at recommended pressures)

Describe ONE way to use energy more efficiently.

Efficiently use energy: includes the use of technology that requires less energy to perform the same function: Change light bulbs and appliances to models that require less energy for the same function

Nuclear fusion

The conversion of the energy within an atom's nucleus to usable thermal energy by forcing together the small nuclei of lightweight elements under high temperature and pressure