APES - Unit 6

Fossil Fuels

Fuels derived from biological materials that became fossilized millions of years ago; provide most of the energy in developed countries

Nonrenewable Energy Resources

Energy source with a finite supply; fossil fuels and nuclear fuels

Renewable Energy Resources

Sources of energy that are infinite

Potentially Renewable

Energy sources that can be regenerated indefinitely as long as it is not overhervested; biomass sources (trees, water)

Nondepletable

Energy sources that cannot be used up (solar, wind, geothermal, tidal)

Commercial Energy Sources

Energy sources that are bought and sold such as coal, oil, and natural gas; developed nations

Subsistence Energy Sources

Energy sources gathered by individuals for their own immediate needs including straw, sticks, and animal dung; developing nations

Energy Intensity

Energy use per unit of GDP (gross domestic product); steadily decreasing for last 50 years (using energy more efficiently)

Fossil Fuel Combustion

Chemical reaction between any fossil fuel and oxygen

Hubbert Curve

Graphical representation of the concept that oil usage will eventually deplete oil reserves worldwide

Peak Oil

When oil extraction and use causes roughly half of the oil supply to be used up

Energy Conservation

Methods to use less energy

Energy Efficiency

Ratio of amount of energy expended to the total amount introduced into the system

Energy to Mass Ratio

Relative size/volume of energy source compared to the actual energy output

Energy Return on Energy Investment

The amount of energy we get out of an energy source for every unit of energy expended on its production

• Energy from fuel/energy invested to obtain the fuel

Biofuels

liquid fuels such as ethanol or biodiesel created from processed or refined biomass

Modern Carbon

carbon in biomass that was recently in the atmosphere; from current plants actively doing photosynthesis

Fossil Carbon

carbon that has been buried for millions of years, out of circulation until humans dug it up & used it

Carbon Neutral

any activity that does not change atmospheric carbon concentrations

Wood

Cellulose in the trunk of trees; harvested by cutting down trees; heat, pulp & paper industry, power plants

Coal

Preserved plant material from 280-360 million years ago; intense heat/pressure underground; electricity generation, industrial processes

Natural Gas

80-95% methane and 5-20% ethane, propane and butane; very few impurities; Electricity generation, industrial processes, fertilizer, home uses

Crude Oil

Preserved organic material from millions of years ago; intense heat/pressure underground; refined by heating to different temperatures; Liquid state makes it ideal for powering vehicles (combustion)

Tar sands (oil sands)

Bitumen/asphalt mix with sand, water, & clay; bacteria metabolize the hydrocarbons; remaining mix is thick & does not flow at room temp; End product of mining is crude oil → goes to refining process, similar uses as crude oil

Peat

Precursor to coal; made of partly decomposed organic material, including mosses

Lignite

A brown coal that is soft sedimentary rock that sometimes shows traces of plant structure

Bituminous Coal

A black or dark brown coal that contains bitumen, also known as asphalt

Anthracite

Has the highest quantity of energy per volume of coal and the fewest impurities; “hard coal”

Natural Gas Water Heater

• Generate heat outside of tank (loss of heat to environment)

• Byproducts from combustion used to heat tank 

• Approx 60% efficient heat to water transfer

• Requires a combustion source; can add air pollution

Electric Water Heater

• Generate heat inside the tank (reduces loss)

• No combustion byproducts

• Approx 99% efficient heat to water transfer

• Extra energy cost to create electricity 

  • Coal burning - less efficient 

  • Renewable source - more efficient

Energy Carrier

can move and deliver energy in a convenient usable form to users

Combined cycle

utilizing steam turbines to generate electricity while also powering a secondary turbine with exhaust from natural gas combustion

Capacity

max electrical output

Capacity factor

actual operating hours of a power plant; takes into account times when plant is shut down

Cogeneration

use of a fuel to generate electricity AND deliver heat (for industrial purposes or for warmth)

Electrical Grid

Network of interconnected transmission lines; delivers electricity from plant to end users

Energy Quality

The ease with which an energy source can be used to do work

Nuclear Power

Electricity generated from the energy contained in nuclear fuel

Radioactivity

Emission of ionizing radiation/particles caused by spontaneous disintegration of atomic nuclei

Radiation

Contains energy that is transferred to the surrounding environment as heat

Fission

Chain reaction started by a neutron hitting a large atomic nucleus; splits into 2 parts; releasing energy as heat

Fuel Rods

Cylindrical tube that houses nuclear fuel within a reactor; filled with U-235 pellets

Control Rods

Cylindrical devices inserted between fuel rods in a nuclear reactor to absorb excess neutrons and slow/stop the fission reaction

Radioactive Decay

Spontaneous release of alpha/beta particles or gamma rays

Half-Life

Time it takes for ½ of the radioactive atoms to decay

Radioactive Waste

Nuclear fuel that no longer produces enough heat to be useful in a power plant

U-235

half life of 704,000,000 years; waste disposal of highest concern

Becquerel (Bq)

measurement of rate at which a sample of radioactive material decays; 1 ___ = decay of 1 atom/second

Curie

Unit of measurement for radiation; 37,000,000,000 decays/second

Biomass

Biological material that has mass; can be solids or liquids

Wood

Usually from trees

Charcoal

Woody material that has been heated enough to drive off water and volatile compounds

Particulates

Particles suspended in the air (soot)

Carbon Monoxide

Colorless, odorless gas formed during combustion

Nitrogen oxides

By-product of combustion of any fuel in the atmosphere

Volatile organic compounds

Organic compounds that evaporate easily

Carbon Dioxide

By-product of all combustion

Manure

Used in regions of the world where wood is scarce

Biofuels

Liquid fuels created from processed or refined biomass; can be used as substitutes for gasoline and diesel

Ethanol

Alcohol made during anaerobic respiration of carbohydrates in plants

Biodiesel

Diesel substitute made by extracting and altering oil from plants

Passive Solar Heating

Using energy from solar radiation without active technology; cannot be stored, used immediately

Active Solar Energy

Technologies that capture and store sunlight with electric equipment and technologies

Solar Water Heating Systems

Range of uses; cold water pumped into heating mechanism; circulates back to storage tank

Photovoltaic Solar Cells

Capture energy from sun as light and convert directly to electricity

Concentrating Solar Thermal Electricity Generation

Use lenses/mirrors to focus sunlight on a small area

Hydroelectricity

Electricity generated by the kinetic energy of moving water

Water impoundment system

Storing water in a reservoir behind a dam

Run-of-the-river system

Water retained behind low dam or no dam, passes through channel with submerged turbine

Tidal Energy System

Energy from the movement of water driven by gravitational pull of the moon

Siltation

Sediment build up in bottom of reserviors

Wind energy

nondepletable renewable energy generated from the kinetic energy of moving air; result of the unequal heating of the Earth by the Sun

Wind turbine

Turbine that converts the kinetic energy of moving air into electricity

Phantom loads

electrical demand of a device that draws electrical current even when it is turned off (gaming consoles, desktop computers)

Brownout

reduced electrical flow from a power plant

Blackout

electrical flow cut off completely

Peak demand

the greatest quantity of energy used at any one time; companies need to be able to supply electricity at this amount & have back up plans

Passive solar design

construction technique designed to take advantage of solar radiation without active technology; stabilizes indoor temps without the use of heating/cooling pumps

Green roofs

roofs with soil and living plants; cool & shade the building/environment and improve air quality

Thermal mass

ability of a building material to stay hot when heated or cold when cooled (high thermal mass has higher ability)