RENEWABLE ENERGYYR. 8 SCIENCE

ELECTRIC CIRCUIT SYMBOLSsymbols used in electric circuits:

**REMEMBER: when drawing circuit diagrams, Always use a Lead Pencil and a Ruler

Drawing Circuits 1) Draw a circuit with a battery and lamp.

2) Draw a circuit with a battery, lamp and open switch.

3) Draw a circuit with a Battery, two lamps and a closed switch.

SERIES VS PARALLEL CIRCUITS Series Circuit: there is only 1 path for the

electricity to flow along.

https://www.youtube.com/watch?v=RQ3djos_LY8

Parallel Circuit: there is more than1

path for the electricity to flow along.

SERIES AND PARALLEL CIRCUITS

• Conduct the experiment on series and parallel

• circuits • Investigate how they differ? • Record all answers on your practical sheet

CURRENT & VOLTAGECurrent: the rate of flow of electrons flowing along a wire in an electric circuit.

Measured in: amperes, or amps for short (A).

Ammeter: device used for measuring current

**Ammeter be placed in series in the circuit

CURRENT & VOLTAGEVoltage: a measure of the electrical energy that causes an electric current to flow.Also known as potential difference

measured in: volts (V).

measuring a difference in voltage, you must connect the voltmeter in parallel across the component whose voltage you want to measure

Voltmeter: device used for measuring voltage.

http://www.youtube.com/watch?v=G1wU8AYGD7Q

Electrical Energy: energy possessed by electrons in an electric circuit. Measured in

joules (J).

Electrical power: a measure of how much energy is transformed per secondin an electric circuit. measured in units called watts (W).

1 W (watts) = 1 J/s (Joules/second)

ELECTRICAL POWER

ELECTRICAL POWER

P= VI

The electrical power delivered (i.e. transformed) by an energy source can be calculated from the voltage across the energy source, and the amount of current flowing in the circuit.

P = electrical power (W)

V = voltage (V)

I = current (A)

The following formula is used:

ELECTRICAL POWER Calculations

1) Voltage was 4V and Current was 16A what was the electrical power?

2)If Current was 10A and Voltage was 6.5V what would electrical power be?

P= VI3)The Voltmeter has a reading of 1.5 V and the Ammeter has a reading of 25mA what is the amount of electrical power ?

ELECTRICAL POWER Experiment

Measurement

Lamp Buzzer Fan LED

Voltage (V)Current (mA)Power (mW)

• Measuring the current and the voltage delivered by the STELR battery to the various components on the STELR testing station.

• We will be able to calculate the power (P = VI) delivered to each part.

• Fill in your results in the table

Transforms the kinetic energy of the wind into mechanical energy of the turbine

then the generator transforms it into electricity.

A good site for wind turbines might have a 35% capacity factor.

Good sights for Wind turbines?

WIND TURBINES

https://www.youtube.com/watch?v=a09vHnVrBi0

Wind Turbines in South Australia

Eyre Peninsula: Port Lincoln

Fleurieu Peninsula: Cape Jervis

Hallet Hill (Burra, Jamestown area)

- Away from obstacles - Highest point possible- Clear space around 10 times

the height of the local

• Best place on top of smooth hilltop

WIND TURBINESSome energy is wasted, due to the fact that

some is transformed into heat and sound energy.

A set of wind turbines that are linked together to supply electricity for a larger population= a wind farm.

Is there a difference between a windmill and wind turbine?

https://www.youtube.com/watch?v=tsZITSeQFR0

WIND TURBINESAdvantages of Wind Turbines:

1. They are a renewable energy source.

2. They do not emit greenhouse gases.

3. They are more energy efficient than most power stations that burn fossil fuels.

WIND TURBINESAdvantages of Wind Turbines:

4. They are cheaper to run than many other energy resources.

5. They can be established in remote areas.

WIND TURBINESDISADVANTAGES OF WIND TURBINES:

1. The electrical power delivered varies because wind speed and direction vary.

2. They can be damaged by strong winds and corroded by salt in the air when near the sea.

3. It can be costly to connect them to the grid, due to the large distances involved.

WIND TURBINESDISADVANTAGES OF WIND TURBINES:

4.Some people believe the sound produced by wind turbines is annoying or even harmful.

5. Some people think they spoil the landscape.

6. Injury or death of birds and animals

https://www.youtube.com/watch?v=79aARWPalt4

https://www.youtube.com/watch?v=lm0Oe8J6qT8

HOW MANY BLADES SHOULD A WIND TURBINE HAVE?

Measure the power delivered by the STELR model wind turbine, and determine how this is affected by the number of blades.

Number of turbine blades 2 3 4 6 12Electrical Power (mW)

(P=VI)

HOW DOES BLADE LENGTH AFFECT THE OUTPUT OF A WIND TURBINE?• Measure the power delivered by the STELR model wind turbine, and determine how this is

affected by the length of the blades.• All groups will set their blade angles to 45.• Each group will compare the number of blades . Starting at:

1. 12 blades2. 6 blades3. 4 blades4. 3 blades5. 2 blades

• Record Results in table: Voltage (V) & Current (mA)• Calculate Electrical Power: P=VI

Show your working out!!!

HOW DOES BLADE LENGTH AFFECT THE OUTPUT OF A WIND TURBINE?

Measure the power delivered by the STELR model wind turbine, and determine how this is affected by the length of the blades

Graphing Wind Turbine Results

Graph 1O Discrete Data: how many blades practical

O Independent variable: No. of blades O Dependent: Power (mw)

Graph 2O Continuous Data: Blade

length O Independent variable:

Blade lengths O Dependent: Power (mw)

https://www.youtube.com/watch?v=niZ_cvu9Fts

SOLAR CELLS

Solar cells, also known as photovoltaic (or pv) cells

Converts the energy from the Sun (i.e. solar energy) directly into electricity.

A solar panel consists of a set of solar cells

SOLAR CELLSAre connected together to produce a desired voltage and current.

A solar array is a set of solar panels connected in a grid

Found on the rooftops of buildings to help meet their energy requirements.

https://www.youtube.com/watch?v=NDZzAIcCQLQ

Solar Panels in Australia

1.1 percent of Australia's electrical energy comes from solar panels

Solar Power Projects in South Australia

Adelaide Showgrounds

Wilpena pound 'Australia's largest' solar farm Royalla, south of Canberra

83,000 solar panels and can power more than 4,500 ACT homes

https://www.youtube.com/watch?v=YD6m98mRBMQ

ENERGY SPELLING WORDS11. appliance12. conservation 13. destroyed14. efficiency15. bicycle16. renewable17. alternative18. geothermal19. turbine20. photovoltaic

1. energy2. kinetic 3. potential4. gravitational5. electricity6. transfer7. transformation8. battery9. kilojoules10. parallel

WHAT POWER CAN YOU GET FROM A SOLAR PANEL?

Four Solar Cells from the Sun

Solar Cells Advantages of Solar Panels:

1. They are a renewable energy source.

2. They do not emit greenhouse gases.

3. Solar energy is free and the panels have a long life.

4. They operate without noise.

5. They can be used in remote areas (e.g. space) where there is no access to an electricity grid.

Solar Cells Advantages of Solar Panels:

6. The heat energy produced can also be used to heat water.

https://www.youtube.com/watch?v=x4CTceusK9I

SOLAR CELLS DISADVANTAGES OF SOLAR PANELS:

1. The amount of power they generate varies due to the changing position of the Sun, cloud cover, etc.

2. They are expensive to install.

3. Greenhouse gases are made during manufacture,

transport and installation of solar panels.

5. They do not produce power at night.

SOLAR CELLS DISADVANTAGES OF SOLAR PANELS:

4. Some people do not like their appearance.

6. They have low energy efficiency ( 10 – 15%).

WHAT POWER CAN YOU GET FROM A SOLAR PANEL?

Four Solar Cells from the Sun

ENERGY SPELLING WORDS1. energy2. kinetic 3. potential4. gravitational5. electricity6. transfer7. transformation8. battery9. kilojoules10. parallel

11. appliance12. conservation 13. destroyed14. efficiency15. bicycle16. renewable17. alternative18. geothermal19. turbine20. photovoltaic