Index● 1 Energy sources. -1.1 Electricity● 2 Electric powers plants. -2.1 Conventional power plants. -2.2 Non-conventional power plants.● 3 Environmental impact.
1 Energy sources● Energy sources are natural resources from which different forms of energy are obtained.
● We can clasify energy sources in several ways: -by availity in nature: renewable or non- renewable. -by origin:primary or secundari. -by use: conventional or mom-conventional. -by enviroment impact: clear or polluting.
1.1 Electricity Electricity is the most widely used form of energy in industrialised societies for two seasons:● Its capacity to be easily transformed into other forms of energy.● The possibility of transporting it long distances at a low cost.
2 Electricity power plants● Electrical power plants use an external source of energy produce electricity. To do this, they rely on a turbine-alternador system. ● The turbine: converts ● The alternador is mechanical energy connected to the into the rotating turbine shaft. As the movement of a shat. shaft moves, it produces alternating electrical current
2.1 Conventional power plants● The thermal power The stean that is plants, water is generated moves the heated in a bolier by turbine connected to the heat generated the generator. from the combustion of a fossil fuel.
● Combined cycle power plants obtain electricity as the result of two combined cycle: that uses air and gas, and a conventional thermal cycle. During the first cycle, a gas turbin is used that incloudes a compresor. The combustion gases from the first cycle are transporte to another boiler, where they transfer their energy.
● Nuclear power plants used a nuclear fission reactor that produce heat to generate the pressurised stean needed to moved the turbine rotor.
● Hydroelectric power plants use the potential energy provided by the height of the water stored in a dam, converting in into kinetic energy. This energy moves the blades of the turbin. There are two tipes: gravity and pump.
2.2 Non-conventional power plants● The enviromental problems caused by conventional power plants have led to the creation and development of non-conventional or alternative energy power plants. ● Wind farms use the kinetic energy of the wind to move the blades of a rotor at the top of a tower; this is referred to as a wind turbine.
● Solar power plants use the Suns energy. There are two types: Photo thermal power plants and Photovoltaic power plants.● Geothermal power plants use the heat found at deep layers in the Earth.● Biomass consists of all organic compounds that are produced through natural processes.
3 environmental impactThe exploitation of fossil fuels and nuclearenergy leads to the depletion of resources.Furthermore, fuel extraction processes aresometimes harmful to the environmentPetroleum is transported by means of oilpipelines and oil tankers both can haveaccidents which means the risk of a spill.