TOPIC: EnergyAIM: How does the earth supply us with energy?

Remember the Law of Conservation of Energy:Energy can’t be created nor destroyed, just changed from 1 form to another

Majorsource ofEnergyon earth

•The sun

NonrenewableEnergyResources

•Resources that can’t be replaced by natural processes as quickly as they are used

•Takes millions of years for nature to reproduce

•formed from remains of ancient plants & animals

•Ex: Coal, natural gas, petroleum, oil

A. Fossil fuels

•When burned release carbon dioxide (CO2)

•Types of:

Petroleum•Formed from plant

remains•Contain stored

energy from the sun•Liquid, highly

flammable

•Used to produce: •A) Oil = burned to produce energy

•B) Lubricants (grease, motor oil)

•C) Plastics•D) Asphalt

NaturalGas

•Burned to provide energy for cooking, heating…

•Burns more cleanly than other Fossil fuels

OIL and NATURAL GAS (Methane)

Even though it was not made from dead plants or animals, nuclear fuel is considered to be a fossil fuel because it comes from the ground and is running out.

Made from the decayed remains of sea creatures which died millions of years ago

Coal •Solid fossil fuel

•90% of coal used is burned to generate electricity

•Creates more pollution

B. Nuclear Energy

•Energy found in the nuclei of atoms

•Power plants convert this to electrical energy

•Advantages:

•1. Do not produce air pollutants or CO2

•2. Single pellet contains energy of 1 metric ton of coal

•Produced from uranium

•Disadvantages:•1. Nuclear explosions •Create big side affects!

Chernobyl, Ukraine, 1986 = reactor core overheated during safety test. Materials in the core caught fire and caused a chemical explosion that blew a hole into the reactor. Radiation was carried by the wind. Twenty-eight people died of radiation sickness.

•2. Water used to cool power plants excess heat may kill organisms in the streams & rivers it’s released into

•All the animals!

•3. radioactive wastes •Where do we put it?

TOPIC: EnergyAIM: How does the earth supply us with energy? Cont’d…Do Now: Complete worksheet- “energy sources”

RenewableResources

•Energy sources that can be replaced as quickly as it is used

•Will be around for millions of years

•Examples:

•1. Wind•Windmills = use wind energy to pump water connected to electric generator

             

•No pollution•Low costs•But if there is no wind no energy

             

•2. Solar energy•(Amt of solar energy that falls

on US in 1 day = more than total amt of energy used in US in 1 year)

•More expensive than using fossil fuels

•3. Moving water•Hydroelectricity = electricity produced from energy of moving water

These use the GPE of water on hills to generate electricity as it flows downhill.

Tidal Power.

•4. Geothermal energy •Heat from earth’s interior (magma)

•Used to generate electricity

•5. Biomass •Renewable organic matter•Example: wood

Ethanol = clear, colorless alcohol fuel made from the sugars found in grains, such as corn & wheat, and potato skins & rice. It is renewable because it is made from plants. To make ethanol we use yeast to ferment the sugars and starch in corn. Corn is the main ingredient for ethanol in the US due to its abundance and low price. The starch is fermented into sugar fermented into alcohol. Other crops such as, barley, wheat, rice, sorghum, sunflower, potatoes, sugar cane and sugar beets can also be used to produce ethanol.