Where does Electricity Come From?

1.Renewable sources2.Non-renewable

sources3.Fossil Fuels4.Nuclear Power5.Solar 6.Wind7.Hydroelectric8.Future Technologies

Learning Goals

• LG: Assess the major social, economic, and environmental costs and benefits of using electrical energy and distinguish between renewable and non-renewable sources.

Success Criteria

• I know the difference between renewable energy and non-renewable energy sources and can give examples of each

Electricity Production

Energy Resources“original source”

Renewable

Renews itself over the course of a normal human life span.

Non-renewableIs not able to replenish itself within a human life span

Non-renewable Resources

Fossil fuels• Oil, gas, coal• Energy released

from combustion is relatively cheap

• The world supply is decreasing

• Pollution problems

Fossil Fuels

Fossil Fuel Electricity Production• (1)Fossil Fuels are burned (2) in order to

heat water which creates steam (3) which causes a turbine to spin (4) which causes the generator to create electricity

1

2

3 4

Fossil Fuels• Coal, oil and gas are called "fossil fuels"

because they have been formed from the organic remains of prehistoric plants and animals.

Electricity Production – Fossil Fuel Power Plants

Nuclear power

Nuclear Fission• Uranium

atoms are broken down releasing atomic energy

• Radioactive waste problem

• Waste materials will be deadly for centuries

• The reactor uses Uranium rods as fuel, and the heat is generated by nuclear fission.

• Neutrons smash into the nucleus of the uranium atoms, which split roughly in half and release energy in the form of heat.

Nuclear• Is the same as Fossil Fuels except that the

heat generated is from a nuclear reaction. Water is heated which creates steam which spins a turbine creating electricity inside a generator.

Electricity Production – Nuclear Power Plants

Nuclear vs. The Rest

End of Day 1

Renewable Resources

Solar• Radiated energy from

the sun• Good for heating• No efficient solar

collection method has been devised yet for direct conversion to electrical energy.

Types of solar

• Solar Cells (really called "photovoltaic" or "photoelectric" cells) convert light directly into electricity.

• Solar water heating, where heat from the Sun is used to heat water in glass panels on your roof.

Solar• The energy gained from the sun is stored

inside a battery which supplies the power• The larger the battery, the more power

that can be stored

Wind

• Kinetic (motion) energy from the wind can be transformed into mechanical energy, then electrical energy is made with turbines and generators (as seen before)

• Windy plains and shallow water are excellent location choices for wind turbines since flat open spaces offer little resistance to high speed winds.

Wind power generator

Electricity Production – Wind Power

Hydro-electric Electricity

Hydro-electric Energy (Dams)

• Water cycle causes evaporation and rain to fall in high geographic areas, then water flows back to sea level.

• The motion of water flowing down is converted to electrical energy as it flows through turbines.

Hydro-electric Energy

A dam is built to trap water, usually in a valley where there is an existing lake.

• Water is allowed to flow through tunnels in the dam, to turn turbines and thus drive generators.

Hydroelectric

Hydroelectric power

Tidal Energy

• The motion of tides is harnessed.

• Similar to hydroelectric, but the cause of the water’s rise is different.

• Shown below is the Annapolis Royal generating station which is the only modern tidal generating station in North America. The station is located in Nova Scotia

Canada• Currently, most of our energy is produced using

Fossil Fuels, Nuclear energy and Hydroelectric means

• Unfortunately other sources such as solar and wind do not produce enough electricity to be a viable source

Energy Source Number of Stations % of total Electricity supply

Fossil Fuels 6 26

Nuclear Energy 5 50

Hydroelectric 69 22

Other 2

Total 100

Future Technology and some that have been tried already

Geothermal

• Thermal energy from beneath the earth’s crust is harnessed to heat water tanks.

• Thermal energy can also be used for the heating of homes

Geothermal

• Hot rocks underground heat water to produce steam.

• We drill holes down to the hot region, steam comes up and is used to drive turbines, which drive electric generators.

Electricity Production – Geothermal Energy

Nuclear Fusion

• Joining Nuclei from small particles to form one large nucleus.

• The “grail” of energy researchers.

• Nuclear fusion is the process that occurs within our sun as hydrogen nuclei combine to form helium.