Solar energy is a primary source of energy which directly obtained from the sun by capturing the solar radiation and converting it into another form of energy to perform various useful activities. The solar energy received by the earth is approximately 1.4 kW/m2. It is known as Solar Constant or Solar Irradiance. For receiving the solar radiation, it is necessary for the collectors to be able to track the sun to ensure a maximum and continuous reception.
There are two ways of solar energy utilization:
1. Conversion of solar energy into thermal energy
2. Photovoltaic cells
The conversion of solar energy into thermal energy can be done by using solar collectors, whereas in photovoltaic cells the direct sunlight is used to generate electricity.
The given schematic diagram of solar power plant depicts four processes:
(i) Photovoltaic (PV) cells convert sunlight to direct current (DC) electricity.
(ii) The inverter converts direct current (DC) into alternating current (AC) electricity.
(iii) The electrical panel sends power to be consumed within property as lights and in appliances.
(iv) The distribution board supplies electricity to grid.
Advantages of Solar Energy
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- Solar energy is a clean, noise free and renewable energy source which causes no pollution.
- Very little maintenance is required to keep solar cell running as there are no moving parts in it.
- In the long term, there can be a high return on investment due to the amount of free energy a solar panel can produce.
Limitations of Solar Energy
- Electricity generation depends entirely on the exposure to sunlight; this could be limited by climate.
- Solar power stations do not match the power output of similar sized conventional power stations; they can also be very expensive to build.
- Solar energy is used to charge batteries so that solar powered devices can be used at night. The batteries can often be large and heavy, taking up space and need to be replaced from time to time.
Applications of Solar Energy
1. Photovoltaic cell
2. Solar thermal power generation
3. Solar drying system
4. Solar Cooker
5. Solar Water and Air Heater
6. Cooling and Refrigeration
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