Alternative sources of energy (comenius)

DEFINITION

There are forms of alternative energy called «clean energies» because they don’t introduce polluting substances in the atmosphere.They are also called «sustainable energy» because they protect the environment and they are at low cost of production.The UE Directives of the 2009 establish that the alternative energiesare:• Hydroelectric energy;• Tidal energy;• Geothermal energy;• Solar energy;• Aeolian energy;• Biomass energy;• Biogas energy.

HYDROELECTRIC ENERGY

The hydroelectric energy is, probably, the earliest renewable energy.The first dam in the history, was built by the ancient Egyptians 6000 years ago.This energy exploits the course of river and the artificial lake created with a masonry dam.

There are two types of dam:• Gravity dam,• Fluent water.

HYDROELECTRIC POWER PLANT

The hydroelectric power plant converts the potential energy in electric energy.The dam carries the water in a penstock which makes some turbines work.The water goes back in the river while an alternator spins.The alternator is connected to the transformer.

HYDROELECTRIC POWER PLANT IN ITALY AND IN THE WORLD

This renewable energy is used all over the world.In Italy it is produced 15% of total energy demand.In China 58%, Brazil 45%, India 42% and Canada 48%.This type of energy raises the tourism which has increased greatly in the last fewyears because the rivers ad the lakes are an attraction for all the people.

TIDAL ENERGY

This energy utilizes high and ebb tide.The water flows in a large basin through of the tunnels where there are a turbine and an alternator.These buildings are too expensive.

The world's first large-scale tidal power plant is the Rance Tidal Power Station in France, which became operational in 1966.

GEOTHERMAL ENERGYThis renewable energy uses the heat inside of the Earth. The earliestindustrial exploitation began in 1827 with the use of geyser steam toextract boric acid from volcanic mud in Larderello, Italy. In the 20th century,demand for electricity led to the consideration of geothermal power as agenerating source. Prince Piero Ginori Conti tested the first geothermalpower generator in 1904, at the same Larderello dry steam field wheregeothermal acid extraction began. It successfully lit four light bulbs. Later, in1911, the world's first commercial geothermal power plant was built there.It was the world's only industrial producer of geothermal electricity untilNew Zealand built a plant in 1958. In 2012, it produced some 594megawatts.There are two types of power buildings: vertical drill line andhorizontal drill line.

GEOTHERMAL ENERGY IN THE WORLD

This energy is accesible only in some nations as UnitedStates, Central America, Indonesia, Estern Africa, Philippines and Italy. These places are very hot so here it is very easy to produce this kind of low cost energy.

Solar energy

It is an important source of renewable energy.This energy comes from the light and the heat of the sun.Active solar techniques include the use of three types of installation:• Photovoltaic system;• Concentrated solar power; • Solar water heating.

AEOLIC ENERGY

It is produced by the transformation of the kinetics energy of the wind in other sources through wind farms. The wind turns the blades, which are connect to the air generator that generates energy.They are about 50 m high and they are a propeller with five blades 20 m long.The wind farm are placed on the land orin the water, so called off-shore.

BIOMASS

This kind of energy comes from the organic materials we have in nature.We can obtain energy throughthree ways:• Action of combustion;• Gasification;• Thermal degradation.

The rubbish, put in a big reservoir, ferments; later it is assembled in a container withairtight closure. From thisprocess we obtainBiogas that is an ecologicalfuel.We also get the fertilizer.

The UE did new legislationsabout renewable energiesand it gave some incentivesfor increasing itsproduction.

ANTONIO SALZANO IIIB