Energy Unit 7

Energy The ability to do work

Energy Resources Most of our energy comes from non-renewable resources ◦ Supplies are limited ◦ Cannot be replenished in a short period of time

We are trying to use more renewable resources ◦ Can be naturally replenished in a short period

of time Alternate-energy sources beyond traditional

resources (fossil fuels)

How do politics and money affect the future of renewables?

Primary vs. Secondary Energy Sources

Secondary sources of energy are called energy carriers ◦ Produced from

primary energy sources ◦ Used to store, move

and deliver energy in an easily usable form ◦ Examples: electricity

Primary source of energy is one that occurs naturally ◦ Examples: Fossil fuels

(coal, oil and gas), biofuels, wind, waves, solar radiation and nuclear fuels.

Non-Renewable Energy Resources

Petroleum (oil) and natural gas-made from the accumulation of microorganisms on the ocean floor

91% of the energy consumed in the U.S comes from non-renewable energy sources ◦ Fossil Fuels-from preserved remains of once living animals

Coal-made when heat and pressure are applied to an accumulation of dead plants under layers of water and dirt

Energy production depends on carbon content ◦ Peat-not yet coal, give it a million years or so ◦ Lignite-softest, most common, used for electricity production ◦ Biturnunous-harder, used in cooking (heating for steel production) ◦ Anthracite-hardest, highest carbon content, produces LOTS of heat,

“clean” coal

Non-Renewable Energy Resources

Uranium (Nuclear Energy) ◦ Common metal

found in rocks-supply is limited ◦ Energy is harnessed

when a uranium atom is split

Non-Renewable Energy Resources

Renewable Resources Biomass-organic material (dead plants and animals) ◦ Contains stored energy from the sun that is released when burned or fermented.

Geothermal-heat energy from Earth’s core ◦ Recovered as steam or hot water ◦ Used to heat building/generate electricity

Hydropower-generated by using flowing water ◦ Hydroelectric power-hydro (water) electric (electricity)

Solar-heat/electricity generated by using radiation from the sun ◦ Photovoltaic devices-convert sunlight directly into electricity

Wind-generates electricity from moving air

#1-Potential Energy-Stored energy and energy of position

All energy forms fall into two categories:

Chemical Energy: Stored in bonds of atoms and molecules (Biomass, petroleum, Natural gas, coal)

Stored Mechanical Energy: Stored by application of force (Stretched rubber band, compressed spring)

Nuclear Energy: Stored in nucleus of atom holds nucleus together Fission (nuclear power plants) split atoms, Fusion (sun) combines atoms

Gravitational Energy: Due to position or place Hydroelectric dams, suspending object

Kinetic Energy-energy of motion

waves, electrons, atoms, molecules, substances, and objects

Electrical Energy: Movement of electrons Electricity, lightning

Radiant Energy: Electromagnetic energy traveling in waves Visible light, x-rays, radio waves, gamma rays

Thermal Energy: Heat, the internal energy of substances and how much particles are vibrating (geothermal)

Motion: Movement of objects from place to place (Wind)

Sound: Movement of energy through substances in longitudinal (compression) waves

Law of Conservation of Energy

It can change forms (and does!)

Energy is neither created nor destroyed

It can change forms (and does!)

What changes of energy can you find in these?

Car crash Food

Ref's Whistle

Typing