2. Alternating Current-The current switches back and forth in direction
Alternating Current-The current switches back and forth in direction. Used in generators, motors, and power distribution centers
Direct current- electricity flows in a constant direction. Used in batteries. There is a positive and a negative terminal
Resistance- the property of a conductor in which the passage of a current causes electric energy to be transformed into heat. Measured in ohms. You want low resistance in electrical wiring!
Capacitor- device for accumulating and holding a charge of electricity
Frequency- the number of cycles or completed alternations in a given unit of time (how many times it turns)

3. Turbine- a machine with a rotor (blades) that are driven by pressure or momentum (such as water pushing them around)
Circuit-the complete path of an electric current, including the generating apparatus, resistors, capacitors, and the load
Motor-converts electrical energy into motion (ex. The fan motor makes the fan turn around)
Generator- converts motion energy into electricity (ex. Generators are found inside power plants, or are gas powered that can power your appliances in a power outage situation)
Transformer- increase OR decrease the voltage of electricity

4. Ground- a conducting connection between an electric circuit or equipment to the earth OR some other conducting body . It turns out that the power company uses the Earth as one of the wires in the power system. The planet is a good conductor, and it's huge, so it makes a handy return path for electrons. "Ground" in the power-distribution grid is literally the ground that's all around you when you are walking outside. It is the dirt, rocks, groundwater and so on. The bare wire running down the power pole runs directly to the earth.
Step up transformer- Increases the voltage in order to travel long distances over transmission power lines
Step down transformer- decreases voltage from 350,000 to 12,000 volts in preparation to go into the home

5. Transmission line- interconnected lines that electricity travels on from the power stations as it makes it way to homes
Distribution lines- overhead OR underground lines that carry electricity to the homes
Substation- small fenced in building that contains transformers, switches, and other electrical equipment
Voltage- the force of an electric charge. The higher, the more charge
Renewable energy- Any naturally occurring source of energy (example: water)
Nonrenewable energy- energy source that has a limited supply (example: fossil fuels, nuclear fuels)

6. Watt- Unit of electrical power
Watt- Unit of electrical power. Appliances require a certain number of watts to work correctly
Kilowatt-hour- measures the amount of electricity used in one hour. (this is how we pay for the electricity we use in homes and businesses)
Efficiency- the ratio of work done to the energy supplied to it (think high effieciency washers. They are efficient in washing our clothes with little water)

7. Greenhouse gases- any of the gases whose absorption of solar radiation is responsible for the greenhouse effect (warming) This includes CO2, ozone, CFCS, methane
Global warming- The increase in the earths average atmosphere temperature that causes changes in climate
Recycling- to treat or process used materials so as to make suitable for re-use
Deforestation- to clear off (cut) forests or trees

8. So What Exactly Is Electricity?
Electricity by definition is electric current that is used as a power source!
This electric current is generated in a power plant, and then sent out
over a power grid to your homes, and ultimately to your power outlets.

9. I guess the next question would be...
What is Electric Current?
The movement of charges such
as electrons is called current, and
this electrical current is what
powers household appliances.

10. So How Is An Electric Current Generated?
Electric current generation - whether from fossil fuels, nuclear, renewable fuels, or other sources is usually
based on the:
Simple Equation
For
Electricity Generation

11. Simple Electric Generator
So simple electric generators found in power plants contain, magnets
and copper wire that when put into motion relative to one another
create the electric current that is sent out to homes.
The major problem in
electricity generation
Is where does the
Motion come from
that keeps the
copper wire and
magnets moving
relative to one
another.
In this case, wind power applies a force to the blades that turns them.
The spinning blades, spin an armature that turns the copper wire
relative to the magnetic field. As long as the blades spin, electricity
will be generated!

12. What Happens At Home? At home, electric current that was generated by
generators in the power
plant is used to power
electric appliances.
The electric current,
running through the
copper wire causes
the armature to spin
which is how most
motors generate
motion.

13. Current Electricity Electrons flow through a conductor
Negative to positive
Circuit = continuous loop for electrons to flow
Needs energy supply (battery)
Energy user (bulb)
Supply = battery
User is bulb
Free electrons need to pass round unbroken circuit
H/O EXPT insulators and conductors

14. CIRCUIT TYPES
The simplest type of circuit involves electricity going around with no “choices” (electrons don’t really choose). This is called a Series circuit.
The other main type of circuit has two or more branches. This is called a Parallel circuit.
Circuit diagram practice H/O series circuits practice drawing

15. Series circuit Has a single loop for electrons to travel round
Components are connected one after another
Current has to travel through all components
Current is the same at all points
Voltage is shared between components
EXPT make buzzer game groups attempt each others

16. Parallel circuit Has two or more paths for electrons to flow down
Current is shared between the branches
Voltage is the same in all branches
H/O drawing parallel circuits
ARB H/O what wrong with circuit?

17. Open & Closed Circuits
Open current stops the flow of electrons (turn light switch off)
Closed circuit allows the circuit to be complete and then they can flow (turn light switch on)

18. SUMMARY In Series In Parallel Current Voltage
The branches share electrons and add to the total
Always the same
Voltage from source = voltage used
Voltage is shared between power users
Current Series is the same
Current Parallel is shared so branches = total
Voltage series from source = voltage used and voltage is shared between users
Voltage parallel is the same in all branches
Voltage is the same in all branches

19. Electricity
Electricity is forced around a circuit by an electrical force field of electrons
Flow of electricity around a circuit is called CURRENT (I) measured in amps (A) by an ammeter
Draw battery +ve has deficit of e-, -ve has surplus so there is a difference in the charge which creates force field pushing electricity
Symbol for current is I (intensity)
Unit of current is amp measured with ammeter
Current AC or DC in batteries flow is in one direction, mains changes direction 50x sec
Voltage is increased as it passes through batteries
Voltage is decreased as it passes through components (bulb, resistors)

20. Voltage (V) – Increase or decrease in the amount of electrical energy carried by the current, measured by voltmeter

21. Current (I) Current is the flow of electrons around a circuit
DC = direct current like battery
Electrons flow in one direction
AC = Alternating current like outlets
the charges move in one direction for a very short time, and then they reverse direction

22. Resistance
electrical resistance - a material's opposition to the flow of electric current

23. Power Grids
Power travels from the power plant to your house through an amazing system called the power distribution grid.

25. electricity is generated in a power plant
electricity is generated in a power plant

26. A transformer designed to increase voltage from primary to secondary is called a step-up transformer.
A transformer designed to reduce voltage from primary to secondary is called a step-down transformer.

27. Transformers (step up) at the power plant boosts the voltage
Transformers (step up) at the power plant boosts the voltage

28. Draw your own flow chart for power grid

29. Step-up and step-down transformers for power distribution purposes can be, some units standing as tall as a home. This photograph shows a substation transformer standing about twelve feet tall:

30. smaller transformers on the poles take that voltage down (step down) to usually 7,200, from the power leaving this substation.

31. Forms of Energy
Mechanical
Chemical
Electrical

32. Forms of Energy
Mechanical- the energy an object has from its motion or its potential.
a. kinetic- an object in motion
b. potential- a result of position or ability to perform work

33. Forms of Energy
Chemical- released in a chemical reaction, often forms heat
Batteries
Biomass
Petroleum
Natural gas
coal

34. Forms of Energy
Electrical- energy made available by the flow of electric charge through a conductor

35. Electricity and Resources
Does it matter how we get electricity?

36. Ways to Get Electricity
Nonrenewable
Fossil Fuels (natural gas, coal, oil)
Nuclear (uranium)
Renewable
Hydroelectricity
Wind
Tidal
Geothermal
Solar

39. Fossil Fuels
Fossil fuels or mineral fuels are fossil source fuels, that is, hydrocarbons found within the top layer of the earth’s crust. 
It is generally accepted that they formed from the fossilized remains of dead plants and animals by exposure to heat and pressure in the Earth's crust over hundreds of millions of years. This is known as the biogenic theory and was first introduced by Mikhail Lomonosov in 1757.

40. Fossil Fuels
Once used up takes MANY, MANY years (longer than our lifetime) to replenish that’s why we call them non-renewable
3 types
Coal
Oil
Natural Gas

41. Fossil Fuels
Fossil fuels are hydrocarbons found within the top layer of the earth’s crust. 
Formed from the fossilized remains of dead plants and animals by exposure to heat and pressure in the Earth's crust over hundreds of millions of years.

42. Disadvantages
Carbon dioxide (CO2) is a "greenhouse gas," trapping heat in the lowest part of the earth's atmosphere. This contributes to "global warming" –

43. Sulfur dioxide (SO2) is a key contributor to acid rain, primarily in the northeast U.S.
Nitrogen oxide contributes to acid rain and smog, as well as health issues such as lung inflammation, immune system changes and eye irritation.

44. They use up valuable and limited natural resources
They can produce a lot of pollution-When coal, natural gas or oil are burned, they release gases into the atmosphere:

45. Hydroelectric power

46. Produced by Using water to turn a turbine to generate electrical
Most hydroelectric power plants have a dam and a reservoir.
Hydropower is the most important and widely-used renewable source of energy.
Hydropower represents 19% of total electricity production.
China is the largest producer of hydroelectricity, followed by Canada, Brazil, and the United States (Source: Energy Information Administration).

47. Hydro Dam
Water rushes through to the Clutha River from Clyde Dam in Central Otago on the South Island of New Zealand.
The largest hydroelectric dam in New Zealand is the Clyde Dam which was built along the Clutha River near the town of Clyde and generates a capacity of 400 megawatts. There are a million cubic meters of concrete in the dam with a further 200,000 in the powerhouse. The Clyde Dam stands at 100 meters in height, 70 meters wide at the base
The Waikato River system is the most highly developed for electricity generation in New Zealand.  It supplies eight hydro-electric stations and provides cooling water for two geothermal and one thermal station.
                     
The eleven stations on the Waikato produce 65% of the North Island's power generation and approximately 25% of New Zealand's hydro power.  This is 15% of New Zealand's total power.

48. Advantages Fuel is not burned so there is minimal pollution
Water to run the power plant is provided free by nature
Hydropower plays a major role in reducing greenhouse gas emissions
Relatively low operations and maintenance costs
The technology is reliable and proven over time
It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there

49. Disadvantages High investment costs
Hydrology dependent (precipitation)
In some cases, using up land and wildlife habitats
In some cases, loss or modification of fish habitat
Fish entrainment or passage restriction
In some cases, changes in reservoir and stream water quality
In some cases, displacement of local populations

50. Nuclear power

51. This is the energy stored in the bonds inside atoms and molecules.
When nuclear energy is released, it can emit radioactivity and heat (thermal energy) as well.
Nuclear

52. Wind Power
Wind power is produced by using wind generators to harness the kinetic energy of wind.
Only provides less than one percent of global energy consumption.

53. Tidal Power
Tidal energy is produced through the use of tidal energy generators.
These large underwater turbines are placed in areas with high tidal movements, and are designed to capture the kinetic motion of the ebbing and surging of ocean tides in order to produce electricity.

54. Geothermal Heat from the Earth It's clean and sustainable.
From the shallow ground to hot water and hot rock found a few miles beneath the Earth's surface, and down even deeper to the extremely high temperatures of molten rock called magma.
The first geothermal power station was built at Landrello, in Italy, and the second was at Wairekei in New Zealand.
The centre of the Earth is around 6000 degrees Celsius - hot enough to melt rock. Even a few kilometres down, the temperature can be over 250 degrees Celsius.
In general, the temperature rises one degree Celsius for every 36 metres you go down.
In volcanic areas, molten rock can be very close to the surface.
Hot rocks underground heat water to produce steam. We drill holes down to the hot region, steam comes up, is purified and used to drive turbines, which drive electric generators.

55. Solar
Energy radiates from the sun and the light rays can be captured with photovoltaics and semiconductors.
Mirrors can be used to concentrate the power, and the sun’s heat is also a thermal source.

56. Solar Solar water heating Photovoltaic cells Solar furnace
Water piped through thin pipe gets heated and stored in insulated tank
Photo cells turn solar energy into electrical not very efficient at the moment
Furnace is an array of mirrors which concentrates suns rays to heat water into steam and turn turbine - possibly arranged as a tower full of turbines surrounded by greenhouse
Demo solar cell lighting bulb/ whistle

57. Transferring Heat Energy
Heat is transferred from hot to cold objects in 3 ways
Heat is transferred from hot to cold objects in 3 ways
Conduction mainly applies to solids as liquids and gases are poor conductors. Heat one side of metal particles vibrate (increase kinetic) and collide with adjacent in so doing pass the energy through the solid. Metal free electrons good conductor, wood, plastic poor therefore insulators
Convection occurs in liquids and gases as the molecules move in currents (magma in mantle) Hot liquid/gas expands, therefore less dense so it rises. Cooler, less dense sinks to replace it. Circular movement called convection current. Day hot air off land rises draws cold air in from sea = sea reeze
Radiation heat from sun travels through vacuum so conduction and convection wont work. Black absorbs and radiates energy best. Hot days wear white not black.

58. Effects of Heating
Temperature Rise
Expansion
Change of State

59. Life Cycles

60. Carbon Cycle

61. Carbon Cycle
In the atmosphere, carbon is attached to some oxygen in a gas called carbon dioxide.
Plants use carbon dioxide and sunlight to make their own food and grow.
The carbon becomes part of the plant. Plants that die and are buried may turn into fossil fuels made of carbon like coal and oil over millions of years.
When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide.

62. Nitrogen Cycle
Like all living things, your body needs nitrogen. Your body gets the nitrogen it needs to grow from food.

63. Most plants get the nitrogen they need from soil.
Many farmers use fertilizers to add nitrogen to the soil to help plants grow larger and faster.

64. Both nitrogen fertilizers and forest fires add huge amounts of nitrogen into the soil and nearby lakes and rivers.
Water full of nitrogen causes plants and algae to grow very fast and then die all at once when there are too many for the environment to support.

65. Carbon dioxide is a greenhouse gas and traps heat in the atmosphere.
Without it and other greenhouse gases, Earth would be a frozen world.
But humans have burned so much fuel that there is about 30% more carbon dioxide in the air today than there was about 150 years ago, and Earth is becoming a warmer place.

66. Oxygen Cycle

67. Oxygen Cycle
Plants are able to use the energy of sunlight to convert carbon dioxide and water into carbohydrates (C6H12O6 -sugar) and oxygen in a process called photosynthesis.