Energy

1. Student 4
Video of thermal power plants: www.youtube.com/watch?v=GI7AhajfhWE
Video of Hydroelectric power plants: www.youtube.com/watch?v=wvxUZF4lvGw
Video of nuclear power plants: www.youtube.com/watch?v=1U6Nzcv9Vws
Transmission and distribution of energy:www.youtube.com/watch?v=TQg2Y0kp2vI

2. Thermal power plants
-Mechanical power is produced by heat engine transforms thermal energy into rotational energy.
-First to produce electricity on an industrial scale.
• Steps for pruducing thermal energy:
1. The fuel is put in the boiler.
2. The heats up the water.
3. The remaining gases released.
4. The vapour moving very fast makes the turbine move.
5. Then the steam cools and returns to the boiler
6. Finally the generator makes electricity
and the transformer adaps it.

3. Hydroelectric power plants
• A hydroelectric power station converts: kinetic energy electric energy
• About 15% of world electricity needs are fulfilled by hydropower.
• Steps for the conversion:
1. The water is collected in a reservoir
2. The control gate is opened and the water flows trough
3. It passes through the penstock and makes a turbine move
4. This turbine powers a generator which produce electricity
5. The transformer adapts it and so we can use it
6. Finally this electricity collected in the powerhouse is distri-
7. buted to the people via power lines.

4. Nuclear power plants
• Nuclear power plants are similar to thermal power plants, but what it differenciate them is the
materal used to heat the water and transform it into steam.
• The material used is uranium and when its atoms split, it produces a nuclear fission and this is known
as a chain reaction.

5. Nuclear power plants
• There are two types of reactors:
• Pressurised water resistor and boiling water resistor.
• They have a very similar function main difference
the PWR makes the process in two different circuits
the BWR makes the process in a sngle circuit
• Steps for the process:
1. The heat from split atoms causes the water to boil producing steam.
2. This steam makes a turbine move which produce electric energy.
3. Afterwards the steam is condensed and returns to the reaction core.

6. Transmission and distribution of energy
• Transmission:
• The energy is transmitted power plants to our houses via electric wires.
• This is called power grid.
• This transmission can be done in two ways:
• Overhead transmission no insulation and are highly affected by the weather
• Underground transmission less affected by the weather, lower danger but high cost prices
• There’s always some energy lost, so we increase the voltage of the current and so if there is higher tension the current is
reduced as well as the loosing energy.
• Finally a key factor is energy cannot be stored, so it has to be produced as needed.

8. Efficiency and energy saving
• It's the goal to reduce the amount of energy required to provide products and services.
• To conserve energy, you need to cut back on your usage
use objects that consume less energy
• Examples:
• Driving your car fewer ours per week.
• Replace your inefficient light bulbs with efficient fluorescent light bulbs
• Turn down your thermostat in winter.
• Unplugging your computer or home appliances when they are not in use.

9. Emviromental impact
• Generation:
• It is very significant our society uses large amounts of electrical power.
• Mostly produced by the burning of fossil fuels coal
natural gas oil
• These resources will not last foreverand destroy our enviroment
• Transmission:
• Electrical energy is transmitted via transmission lines
• A 12% of it is loosed during the process in the form of heat
• That it's called Joule effect
• Distribution:
• The power plant producess 25,000 volts and the transformer
changes it up to 400,000 volts aproximately
• In our houses is transformed into-220 volts for larger appliances
and 110 volts for smaller ones

10. Emviromental impact
• Use of energy:
• Buildings are responsible for 40% of the total world annual energy consumption.
• Instead of using fossil fuels that can run out, use renewable sources such as sun rays.
• We use much more energy than what we need
so large amounts of fossil fuels are burnt this affects the atmosphere and contaminate the air.