Tecnologia, 2 ESO, CLIL, AICLE Technologies

1. CLIL Technologies
2nd ESO
Jordi Pipó Vicent

2.  Where does the electricity transported by high voltage
power lines come from? Where does it go?
 What is a thermal power plant?
 What are the solar panels located on the roofs of some
buildings used for?

3.  Buildings or facilities that use primary energy
 Primary energy is converted to mechanical energy
 Finally, to electricity

4.  Turbine-alternator system
 Turbine: converts mechanical energy into the rotating
movement of a shaft.
 Alternator: consists of two parts:
 Stator: fixed part.
 Rotor: moving part connected
to the shaft.

5.  Transport and distribution of electricity
 Transformers: facilities that convert electrical energy
 Transport: increase the voltage (220-400kV) avoiding the Joule
effect, decrease the voltage with substations reducing it to 230-
400V.

6.  Energy sources
 Natural resources from which we obtain different forms of
energy for a specific use.
 Explain the difference between the concepts of source and form
of energy.
 Think about five different energy sources.

7.  Types of power plants
 Renewable : These sources are inexhaustible, therefore we can
use them continuously.
 Non renewable : These sources are exhaustible, therefore we
consume the source when we use it.

8.  Types of power plants
Energy
source
Renewable Non
renewable
Hydraulic X
Geothermal X
Nuclear X
Wind
power
X
Solar X
Petroleum X
Coal X
Natural gas X
Biomass X
Tidal
power
X

9.  Thermal power plants
 Water is heated in a boiler heated with natural gas or coal. The
steam moves a turbine.
 Advantages: cheap production.
 Disadvantages: CO2, acid rain, global warning, non renewable.

10.  Combined cycle power plants
 First cycle: a gas turbine with a compressor where gas mixed
with air is burnt. Generates electricity. Resultant combustion
gases are transported to a boiler.
 Second cycle: Water boils. The steam moves a turbine
generator system. Produces new electricity.
 Advantages: more efficient, less pollution.
 Disadvantages: CO2, acid rain, global warning, non renewable.

11.  Nuclear power plants
 A nuclear fission reactor produces pressurized steam which
moves a turbine motor. Uses uranium as a fuel.
 Advantages: high production, no CO2.
 Disadvantages: dangerous waste and accidents, non renewable

12.  Hydroelectric power plants
 Uses the potential energy provided by the water stored in a
dam. Potential energy is converted to kinetic energy. The water
moves the blades of a turbine.
 Advantages: no greenhouse gases, renewable.
 Disadvantages: drought season, flooded area.

13.  Photo-thermal power plants
 The heat generated by solar radiation produces steam. The
steam moves the rotor in a generator. A mirrors called
heliostats reflect sunlight to one point in a tower.
 Advantages: clean, renewable, used in isolated houses.
 Disadvantages: don’t work at night, low energy, big lands.

14.  Photovoltaic power plants
 Solar radiation is transformed directly into electricity by
panels of photovoltaic cells. Panels are made of silicon.
 Advantages & disadvantages: the same as photo-thermal.

15.  Wind power plants
 The wind moves the blades of a rotor at the top of a tower.
 Advantages: clean, renewable, isolated houses.
 Disadvantages: low energy, places with appropriate
conditions, noise, visual effect.

16.  Geothermal plants
 Use the heat found at deep levels in the earth. The steam moves
a turbine and produces electricity. It can be used also for
heating.
 Advantages: clean, renewable.
 Disadvantages: not many places, short life time.

17.  Ocean power plants
 Tides: mechanical energy. Special sides, dam.
 Waves: mechanical energy. Electricity transport to the land.
 Ocean’s thermal gradient: pollution, deep ocean.
 Advantages: clean, renewable.
 Disadvantages: experimental phase, low production.

18.  Biomass thermal power plants
 All organic compounds produced through natural processes.
Forestry and agricultural waste, crops like sunflowers or sugar
beet, agri-food industries waste.
 The steam generated moves the turbine. It can also be
converted to charcoal, alcohol or biogas.
 Advantages: waste with no other use, cheap.
 Disadvantages: greenhouse gases, not enough land, energy
instead of food. .

19.  Fusion plants
 Work like the Sun. Need hydrogen. Join the atoms.
 Advantages: clean, renewable.
 Disadvantages: may be in the future, extremely high
temperatures.

21.  Extraction of natural resources
 Depletion of fossil and nuclear fuels.
 Fuel extraction can damage the environment. For example,
timber extraction in big areas or water pollution.

22.  Fuel transport
 Oil is transported by oil pipelines and oil tankers.
 Oil tankers have accidents at sea with the risk of oil slicks.

23.  Electricity generation
 Conventional thermal power plants:
 Air pollution: CO, heavy metal molecules, …
 Greenhouse effect: CO2
 Acid rain: SO2, NO

24.  Electricity generation
 Nuclear thermal power plants:
 Nuclear accidents: Chernobyl, Fukushima, Vandellós
 Nuclear waste: radiation can last thousand of years.

25.  Waste treatment
 Thermal power plants: filters, coal with a low sulphur content,
increase the size of large forested areas, low temperature combustion,
decrease the use of coal.
 Nuclear power plants: waste stored in thick drums in underground.
They don’t let the nuclear radiation escape.

26.  Some solutions
 Efficiency: policies, reduction of energy (electric cars, home insulation,
low fuel cars, …).
 Energy diversification: renewable sources.
 Energy savings: shared cars, public transports, local goods.