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4th “Newsletter” – abril 2014 – Portugal Theme: “Alternative energy sources/renewable energy”

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Natural resources

We call natural resources to all elements that

are in the Nature, used by man to improve his

life. The sun, wind and water are some of these

resources.

Renewables

We call renewable energy to all energy

sources that do not deplete.

Renewable energy is virtually inexhaustible,

but limited in terms of the amount of energy that

can be extracted at any time.

Renewable energy sources are characterized

by their capacity to regenerate and, as such, are

virtually inexhaustible and still respecting the

environment.

Both properties are its main difference with

respect to traditional energy sources.

Solar energy, wind energy, hydropower,

geothermal energy, wave energy, tidal and

biomass are renewable energy.

Solar energy

It is used to produce heat through solar

panels, or to produce electricity through

photovoltaic panels. During its construction, the

Solar Photovoltaic of Amareleja (Portugal), in

2008, was the largest in the world.

Photovoltaic of Amareleja

To capture solar photovoltaic panels (panels

with small light sensitive cells) are required.

When the sun's rays reach these cells, it produces

a reaction called photoelectric effect. It generates

electric current that can be consumed at the

moment or stored in batteries.

Wind energy

The wind turbines or wind generators are

used to produce electricity using the wind force.

“Caramulo” Wind Farm

The wind turbine comprises a tower, in its top

blades and a box called "nacelle" are installed.

The wind moves the blades of the turbine. Inside

the "nacelle" there are gears that increase the

speed produced by the blades and a generator

that transforms this motion into electricity.

Hydropower

It uses the power of water to produce electricity.

But for this to be possible, it is necessary to build

a dam.

Hydroelectric dam of Castelo de Bode

In a hydropower plant is the strength of the

accumulated water in the dam which drives a

turbine connected to a generator. From its

rotation results the production of electricity.

Geothermal energy

Inside Earth Planet exists much heat. But in

some locations this heat is closer to the surface

and can be harnessed to produce electricity. It's

what happens in this geothermal power station

located in the Azores Island (Atlantic Ocean)

Geothermal Central of Pico Vermelho - São Miguel Azores

Here was installed a pipe through which the

water runs and becomes steam due to the

temperature. It is the steam which drives the

turbine which is connected to a generator, which

transforms this movement into electricity.

Wave energy and tidal

Harnessing the energy released by the

movement of waves and tides. These movements

drive a turbine connected to a generator,

producing electricity.

WaveRoller in baleal - Peniche

Biomass

Biomass uses urban, forest and agricultural

residues. There are several types of biomass:

• With timber we build fires and produce heat.

• With vegetable and animal oils we can produce

biodiesel.

• Using organic matter can produce biogas, as

this plant.

It can still be transformed into biofuel, called for

biodiesel.

Unit Energy Use of Windward in Portimão (south Portugal)

The biomass is transformed into gas by

chemical processes, which can be used in

engines, for heating and electricity production.

Did you know that ...

Energy from the sun takes 8.5 minutes to reach Earth?

The sun's energy can be used to heat water?

In the Azores Islands people use up energy from inside the earth to make the stew from Furnas?

In the Tagus river tide mills still exist in activity that harnesses the energy of the ocean?

In Portugal almost half of the electricity comes from hydropower?

Work made by students of class 5th A