fossil fuelsspeech transcript
speech transcript
VittoriaInternationalSchool - Torino
from fossil fuels
to alternative energy sources
in accordo con il
Ministero dell’Istruzione, Università, Ricerca
e sulla base delle
Politiche Linguistiche della Commissione Europea
percorso formativo a carattere
tematico-linguistico-didattico-metodologico
scuola secondaria di secondo grado
professor
Elena Tibaldi
1
eniscuola / smartenglish – A cura di Linda Rossi Holden Label europeo 2010
fossil fuelsspeech transcript
From fossil fuels to alternative energy sources
Good Morning.
Today I am going to talk about the fossil fuels and alternative energy sources.
Why do we need energy? For transportation, for production of electricity, for house heating and for cooking gas.
Which are the traditional energy sources? Coal, petroleum or oil, natural gas.
The traditional sources are depleted by use are widely used at present and they will be exhausted in the near future.
What is coal?
Coal is a solid fossil fuel, responsible for the development of western industrial growth.
Coal is used for production of electricity in thermal power stations, and in production of chemical compounds. CO2 emission upon combustion causes environmental pollution.
What is petroleum?
Petroleum is a mixture of different hydrocarbons derived from decomposition of organic matter in anaerobic conditions.
Through fractional distillation, crude oil is boiled and condensed over several fractions to give the desired mixture of compounds, so we can obtain: natural gas, gasoline, kerosene, up to bitumen and asphalt.
What is natural gas?
It is a mixture of hydrocarbons, mostly methane. In the worldwide, natural gas reserve mostly are in Middle East and Eurasia.
In its pure form, natural gas is colourless and odourless. So for safety reason and detection leaks,mercaptan is added to the gas before delivering.
Which are the problems related to the use of hydrocarbons?
First of all CO2 production causes environmental pollution and consumption of world reserves determines an increase of costs and extraction and transportation are often object of environmental disasters.
Which are the alternative sources?
Nuclear energy for example. Some of the alternative sources are also renewable, for example:
solar energy, wind energy, hydro-electric energy, biomass, tidal and geothermal energy.
What about solar energy?
It produces hot water with solar thermal energy or electricity production with photovoltaic solar energy.
Wind energy is converted into electricity by using turbines and generators so the kinetic energy is transformed into electric energy.
Wind farms are groups of wind turbines in the same location.
Geothermal energy: exploiting endogenous heat inside the earth and with the technological improvements no geographical limitation is due to the power plants.
Hydroelectric energy is exploiting gravitational force of falling or flowing water, so potential energy of dammed water drives a water turbine and a generator.
An example of hydroelectric energy is the tidal energy which exploits daily rise and fall of tides.In Saint-Malo, France, a 13,5 m gap between low and high tide is exploited for energy production.
Nuclear energy is using fission of uranium which releases thermal energy which is exploited to produce water heating and steam production to (obtain) the production of electricity.
But it is a controversial issue because of disposal of radioactive waste.
Biomass energy is exploiting garbage, wood, waste, landfill, gases and alcohol fuels and using conversion technology goes up to production of heat and electricity.
In conclusion, in this video we revised the most important traditional energy sources as well as alternative sources of energy. Good bye and good energy to everyone!
Materiale sviluppato da eniscuola nell’ambito del protocollo d’intesa con il MIUR
1