geothermal, nuclear, etc

Fossil Fuels

Derived from biological materials that became fossilized millions of years ago.

Coal, Oil, and Natural Gas

Come from deposits of organic matter that were formed 50 million to 350 million years ago.

Nonrenewable Energy Source

Finite supply.

Calorie

Amount of energy it takes to heat 1 gram of water 1 °C, used in human food consumption and energy transfer.

Calorie (Food)

Calories in food.

Btu

British thermal unit, energy it takes to heat 1 pound of water 1 °F, for energy transfer in air conditioners and water heaters.

kWh

Kilowatt-hour, amount of energy expended by using 1 kilowatt of electricity for 1 hour, for energy use by electrical appliances.

Best Candidates for Replacing Nonrenewable Fossil Fuels

Solar and wind.

Conventional Energy Resources

Petroleum, natural gas, coal, uranium ore (nonrenewable).

Renewable Energy Sources

Infinite sources of energy that fall under two categories: potentially renewable and nondepletable.

Potentially Renewable

Can be regenerated indefinitely as long as they are not consumed more quickly than they can be replenished, e.g., wood, biofuel.

Nondepletable

Cannot be used up no matter how much is used, e.g., solar, wind, geothermal, tidal energy.

3 Largest Energy Sources

Oil, coal, and natural gas (80%).

Percentage of Global Energy Use that is Renewable

15%.

Largest Renewable Source

Hydroelectric, followed by wind and solar.

Commercial Energy Source

Sources that are bought/sold; coal, oil, natural gas, wood, charcoal, and animal waste.

Subsistence Energy Sources

Sources that are gathered by individuals for their own immediate needs; straw, sticks, animal dung.

Major Outputs of Energy

End use of energy (transportation, residential, commercial, and industrial) and waste (heat, CO2, pollutants).

Fossil Fuel Combustion

Chemical reaction between any fossil fuel and oxygen, resulting in CO2 and other greenhouse gases.

Hubbert Curve

Bell curve representing oil use, maximum use, and when oil will be depleted - 2 estimates (lower and higher).

Peak Oil

Point where half the oil supply has been used up and use will decline.

Energy Conservation

Finding and implementing ways to use less energy.

Energy Efficiency

Ratio of the amount of energy expended in the form wanted and the total amount of energy introduced into the system.

Energy for Transportation

Gasoline or diesel fuel (liquid is compact and has a high energy-mass ratio).

2nd Law of Thermodynamics

When energy is transformed, its ability to do work diminishes because energy is lost during each conversion.

Energy Lost as Waste Heat

⅔.

Energy Return on Energy Investment (EROEI)

Energy obtained from fuel / energy invested to obtain the fuel.

Concerns About Nuclear Power

Radioactivity, use of weapons, potential for accidents.

Radioactive Decay

Spontaneous release of material from the nucleus when the isotope emits alpha/beta particles or gamma rays.

Half Life

Time for ½ of the original radioactive parent atoms to decay - allows scientists to know how long an element may be dangerous.

Radioactive Waste

Nuclear fuel that continues to emit radioactivity; stored in special, secure locations.

High Level Radioactive Waste

Used fuel rods; causes immediate damage by organ failure, radiation sickness, death.

Low Level Radioactive Waste

Contaminated PPE, tools, rags, mine tailings; causes DNA damage, cancer, tumors.

Bq

Becquerel measures rate that a sample of radioactive material decays; 1 Bq = decay of 1 atom per sec.

Curie

Unit measure for radiation; 37 billion decays per sec.

Radioactive Waste Disposal

Stored in water or lead-lined containers (cannot be burned).

Geothermal Energy

Heat energy that comes from the natural radioactive decay of elements inside of the earth.

Heat Exchangers

Collect heat by circulating liquid underground until it is heated.

Disadvantages of Geothermal Energy

Less accessible, expensive to drill wells, hydrogen sulfide and methane can be emitted.

Ground Source Heat Pumps

Transfer heat from ground to a building (technically comes from solar energy).

Hot Water Heat Pump

Extracts heat from the air then transfers it into a domestic hot water tank.

Fuel Cell

Electrical-chemical device that converts fuel into electrical current.

Advantages of Fuel Cells

Only waste is energy and water.

Disadvantages of Fuel Cells

Requires hydrogen, must be separated.

Electrolysis

Electric current is applied to water to split it into hydrogen and oxygen.