Basics of Solar energy

What is solar energy?

In simple terms solar energy is the energy provided by the sun. Solar energy comes in the form of radiation, which in turn helps to produce electricity. It is actually the light and not the temperature that matters when it comes to producing electricity from solar energy.

The Real Working

The light energy is converted into usable solar energy by the panels, with the help of N type and P type semi-conductors. When lights falls on the panels, it is absorbed and it knocks electrons from their atoms, which in turn allows electrons to run through the material which in turn produces electricity. Solar panels mainly convert about half of the ultraviolet and infrared spectrum, while most of the visible light is usable solar energy.

Different Solar Energy Technologies used in the Indian Market 

Photovoltaic (solar cell) systems – Solar cells are often used in the past to power calculators and watches. They are mainly made up of semiconductor material. They are used to convert light (photon) into electricity (voltage) which is called as photovoltaic effect (PV) effect. Solar cells are normally mounted on a module, which would contain about 40 cells. These modules are connected together and used to power houses partly or fully. They are mounted on rooftops or on floors with the help of structures facing in the south direction with a small tilt which depends on the geographical location of the site.

The performance of a solar cell is usually measured in terms of its efficiency of converting light into electricity. Usually on the market the average efficiency of cells are about 14-15%. There are higher quality cells available which gives about 30 -35% efficiency but those panels are very costly and hence not feasible for everyday projects. The first solar cell was built in 1950 and it had about just 4% efficiency.

Solar Hot Water – For solar water heaters the panels are setup in a way so that they are facing south (this is to  make sure that the system receives more of the sunrays throughout the day).  This  system consist of mainly 2 parts. A solar collector and a storage tank. Most of the  systems come with a flat plate collector having a transparent cover that faces the sun.  There will be small tubes running through the box carrying water to be heated. Once    the heat starts building up in the collector the water running through the tubes also  gets heated up.

The storage tank is responsible for holding the hot liquid. It usually comes in 100Litres or 200Litres in the Indian market. Another type of classification comes in this system when it comes to the way the heated water is transferred. Active system uses a pump to transfer the water while passive system using the normal gravitation force.

Environmental impact

• Solar energy is one of the forms of cleanest energy as it doesn’t produce any greenhouse gases. In effect setting up a solar system helps in offsetting CO2 from the earth’s atmosphere. 10kw solar electricity will help to reduce about 10kg of CO2 equivalent.
• Solar energy doesn’t produce smoke.
• It doesn’t involve destroying the environment.
• Conserves so much water used in electricity production.
• Eliminating the needs to burn fossil fuel.
• Planting acres of trees.