Electricity Generation-energy & power

Today we will learn …

•What is energy?

•What is power?

•What is electricity?

•How is electricity generated?

What is Energy ? … What is Power ???

Energy is what makes things happen!•Electricity is a very useful type of energy that we use every day to make things happen.

Power is (basically) how fast energy is used.•We can use energy quickly, or we can use it more slowly.

Energy & Power.

• Energy is what makes things happen. Measured in Joules (or Calories).

• Law of Energy (energy can neither be created or destroyed, it can only be transformed).

• Power is how much energy is transformed in 1 second. Measured in Joules per second, Watts or kilo-Watts.

• Electricity industry measures and charges for energy in kilowatt hours (kWh).

Example

Toaster:• Power rating = 2 kW• Time on = ¼ hour• Energy used = 2 x ¼ = 0.5 kWh

Light bulb:• Power rating = 100 W = 0.100 kW• Time on = 5 hour• Energy used = 0.1 x 5 = 0.5 kWh

Electricity is … a type of energy

Where does our Electricity come from in NZ?

NZ Energy Generation 2010

Geothermal, 12.8%

Gas, 21.2%

Coal, 4.5%

Wind , 3.7%

Other*, 1.4%

Hydro, 56.4%

How is Electricity Generated?

- Types of Power Station -

Hydro (spilling excess water)

Hydro

Hydro (pipes dropping down to turbines)

Francis turbine (right) and inlet scroll (left)

Turbine spins a generator

Hydro (Pelton turbine)

Pelton turbine and generator

Make your own Pelton Turbine - Generator

Wind

Enercon E126 wind turbine: •Tower 135m, •Blades 126m diameter, •Power output 7MW.

Thermal (Fossil fuels)

Geo-thermal

Solar Farm

Solar (Photo-voltaic)