Solar energy is a clean energy as it generates neither greenhouse gas emissions nor pollution. Today, solar energy represents less than 1% of all energy produced by humans and Germany is the country that produces the most.
There are two technologies for generating electricity from solar energy: photovoltaic panels and solar thermal power plants.
Photovoltaic Solar Panels
Photovoltaic panels work alone without any human intervention. Their usage is so simple which is the main reason they are already being used on a daily basis at home. And regarding their efficiency and low costs, it’s predicted that they will be used more in the future.
Each solar panel captures energy from sunlight and converts it into electricity using the silicon it contains. Electricity is then transported by underground cable to users.
The Solar Thermal Electricity
Solar thermal energy is very effective and is the preferred type of solar energy in hot countries. But it has some cons as power generation is more complex: you must dispose of mirrors, pipes and turbines. It is therefore appropriate to use this technology in large power plants to produce large amounts of electricity.
How does it work? Well, large curved mirrors reflect heat from the sun on a pipe. Inside the pipe circulates a heat transfer fluid (which carries heat). It gets very hot: several hundred degrees Celsius. The liquid moves inside the pipes then heats the water reservoir. The water boils and the steam turns the blades of a turbine which a device that produces electricity.
No sun? During the day, the heat transfer liquid melts specific salts in a large bowl. At night, these salts become solid and release their heat. This is then used to generate electricity, such as during the day.
Basma – Green Energy International Correspondent – 11/12/11