Written by Kumara Velu in Energy
Viewed by 243 readers since 03-31-2009
You may be wondering how solar energy is created. Well, solar energy is produced by trapping the rays of the sun into solar cells that convert the light into electricity. When solar energy is converted into heat or thermal energy it can be used to heat water in homes, swimming pools and buildings. It could also be used to heat spaces as in greenhouses, homes and other buildings. There are two ways through which solar energy could be converted into electricity.
1. Photovoltaic Energy
The first is through photovoltaic devices also known as PV devices or popularly known as solar cells. They are commonly used to power watches, calculators and also lighted road signs. The photovoltaic cell was discovered in 1954 by researchers working for Bell Telephone. Towards the end of the 1950s, it was used to power space stations belonging to the USA.
The main advantage of a photovoltaic system is that conversion of sunlight to electricity is easy and direct. There’s no need to install large mechanical generators to get the conversion done. The impact on the environment is also minimal. You don’t even need water to cool the system and no harmful by-products are generated.
2. Solar Thermal Energy
This is a more popular form energy used to heat swimming pools and water in homes. There are two heating systems involved – passive and active. In passive heating, no mechanical device is required to generate heat. Air is circulated via a solar heat surface into a building through convection. On the other hand, an active heating system requires the use of a collector to absorb and keep solar energy. In such systems, circulation is necessary and fans and pumps are used to circulate the heated air.
Solar Energy Power Plants
Such plants are used to generate electricity. They make use of sunlight to heat a kind of fluid that is later turned into steam. The steam is then turned into mechanical energy through the help of a turbine. This energy is then converted to electricity through a generator attached to the turbine.
The main advantage of solar energy is it’s available all the time. In other words, it’s a renewable source of energy. As has been mentioned earlier, it doesn’t harm the environment. It causes no water or air pollution because no hazardous chemical reaction is produced in the process of generating it.
The sun doesn’t shine every day. When the sun is not shining, no energy is produced. Also, the amount of energy produced on cloudy days or at night is limited. Solar power stations are costly to build. Similarly, installing a solar energy system in your house may burn a hole in your pocket.
Despite these shortfalls, solar energy is still an attractive option for those concerned with safeguarding the environment. One thing is certain – solar energy doesn’t contribute to global warming.