How do Solar Panels work

Here you will find useful information on how do solar panels work…

Let’s start by explaining the basis, the photo-electric effect

 

 

The photovoltaic is the direct conversion of sunlight to electricity. Light striking solar cells is converted into electric energy. This occurs according to a principle called the ‘photo-electric effect’. Solar electric devices are also called photovoltaic or PV devices.

The photo-electric effect was first discovered during the 1830s by a French physicist, Alexandre Edmond Becquerel, who noted that certain materials produce electric current when exposed to light. The amount of power produced, however, was insignificant and the property did not find a useful power- generating application until the 1950s, when the United States space program decided that solar cells would be a good electrical power source for satellites. Following the oil crisis in 1973, much research was put into improving PV technology for applications on Earth. The first automated production of solar cells began in the US in 1983. By 1990, the industry was well established and growing. Today solar cells are manufactured in many countries, led by China, Germany, Japan, Spain, the US and India. Figure 1.1 shows the increasing trend for world shipments of PV modules since the mid-1990s.

 

A basic explanation of how solar cells work:

Solar cells rely on the special electric properties of the element silicon (and other semiconductor materials) that enable it to act as both an insulator and a conductor. Specially treated wafers of silicon ‘sort’ or ‘push’ electrons dislodged by solar energy across an electric field on the cell to produce an electric current. Other materials are also used but the vast majority of solar cells are made from silicon.




Solar radiation is made up of high-energy sub-atomic particles called photons. Each photon carries a quantity of energy (according to its wavelength); some photons have more energy than others. When a photon of sufficient energy strikes a silicon atom in a solar cell, it ‘knocks’ the outermost silicon electron out of its orbit around the nucleus, freeing it to move across the cell’s electric field, also called the p-n (positive-negative) junction. Once the electrons cross the field, they cannot move back. As many electrons cross the cell’s field, the back of the cell develops a negative charge.

If a load is connected between the negative and positive sides of the cell, the electrons flow as a current. Thus, solar energy (in the form of photons) continuously dislodges silicon electrons from their orbitals and creates a voltage that ‘pushes’ electrons through wires as electric current. More intense sunlight gives a stronger current. If the light stops striking the cell, the current stops flowing immediately.

 

 

Please watch the following short video to see a detailed explanation on how do solar panels work…