ELECTRIC POWER PLANTS

By: Maria Garca Bermejo and Mara Alejo Hernndez.I.E.S Rodrguez Moino 3A 2011/2012

INDEX

There are different types of power plants depending on the source of the energy:Nuclear power plants

Fossil fuel thermal power plants

Hydroelectric power plants

Wind power plants and wind farms

Solar power plants

Geothermal power plants

Biomass thermal power plants

Ocean power plants

Curiosities

Nuclear power plants

These nuclear power plants burn the radioactive material (mainly uranium), to produce electricity.

Process in the nuclear power plants

First, uranium is burned in the reactor and inside the control rods, nuclear fission takes place.

Water in the reactor is heated to very high temperatures.

Then it's transported to the steam generator where the reaction of hot and cool water produces steam

The steam moves a turbine that produces electricity.

This electricity is then induced into the electric network.

While this occurs the steam produced is cooled down again to water, and is transported to the reactor.

The process is repeated.

Thermal power plants

Process in thermal power plants

These types of power plants, use fossil raw materials such as coal,natural gasl or petroleum in order to heat water in a boiler. The steam produced is then transported to a turbine and makes it turn. The turbine is connected to an electric generator that produces electricity. The steam is converted again to water and the result is the realisng water vapour through the cooling tower.

Hydroelectric power plants

Process in hydroelectric power plants

These types of power plants use the force of water accumulated in a dam in order to make a turbine move. Again the turbine is connected to an electric generator and produces electricity. The characteristics of the obtained electricity are modified in the transformer to high voltage in order to be transported. When it reaches the electric network near the cities and towns, the voltage is then reduced in order to be consumed.

Wind power plants and wind farms

Process in wind power plants

The nacelle is a metallic box in which a series of electric machines measure the physical characteristics of the wind. When a curent of wind cames, the blades move the generator inside the nacelle. The process in the hydroelectric network is then repeated, tranporting the electricity to the far away cities, passing first through a transformation and control substation.

Solar power plants

We can find two different types: Photo-thermal and photovoltaic power plants

Characteristics

PHOTOVOLTAICRadiation from the sun reaches photovoltaic cells that are capableof transforming it into electricity.

They are usually located in large areas.

Can also be obtained at home and then sold to the electric grid.

PHOTO-THERMALThe sun heats water and water vapour is produced in order to move a turbine. The turbine is conected to a generator that produces electricity.

Special mirrors are required to reflect the sun light to the boiler.

Geothermal power plants

This type of energy source is able to produce energy in two ways:

DIRECTLYThe internal heat of the Earth is used for storing hot water and heating in industrial and domestic use.

INDIRECTLYThis is the process in which the (unwanted) water vapour produced in the direct one is used (recycled) to produce electricity through a generator.

Biomass thermal power plants

Process and characteristics

This power plant uses energy from recycled waste that has non-potential use to produce electricity such as agricultural waste, agri-food industrial waste and specific crops.

These wastes are burned and as a consequence steam is produced which again moves a turbine conected to a generator.

The main disadvantage is the huge quatities of CO2 released to the atmosphere.

OCEAN POWER PLANTS

Characteristics

It uses three different types of energy from the sea:-the mechanical energy from the tides-the mechanical energy from the waves-the energy from the ocean's thermal gradient

Its principal aim is to move a turbine that is connected to a generator that produces electricity.

Advantages and disadvantages

AdvantagesIt is a clean form of energy that takes advantage of the natural force of the sea such as the waves and the tides.

It benefits from the differences in temperature between the surface and the ground soil, creating energy from the thermal gradient.

DisadvantagesIts productivity is very low because ocean power plants aren't still totally experimented.

It causes environmental impact and affects the development of the species.

Curiosities: Wind turbine creates water from thin air

This ecological purpose aims to help arid and desertic areas that have low manufacture of drinking water by taking advantage of a renewable energy. How? It's easy, the energy produced in wind power station is used to make a water generating system works. This process extracts humidity from the air and stores fresh water into stainless steel pipes. This process has been discovered by a French firm and the good point about it is that it can took place anywhere.

The end