On a bright sunny day, the sun produces approximately 1000 watts of energy per square meter of the earth’s surface. If we could collect that vast energy source, we could power our homes and offices for free. Solar power is often used synonymously with solar energy or more specifically, to refer to the conversion of sunlight into electricity. This is being done through the photovoltaic effect.
A solar cell or photovoltaic cell is a device that converts light into electricity using the photoelectric effect. Solar cells are made of the same kinds of semiconductor materials, typically silicon, which are used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current — that is, electricity.
Photovoltaic cells and panels are the most used method for taking the power of the sun and turning it into electricity.
A number of solar cells electrically connected to each other and mounted in a frame that is called a “photovoltaic module”.
Some of the modules of today’s design are rated as high as 300 watts each. When we combine photovoltaic modules together, (called an array), we can achieve the desired amount of electricity produced for the specific need. The modules in arrays can be connected in both series and parallel to produce the required voltage and current. The current produced by the modules is a Direct Current (DC) and has to be converted into Alternating Current (AC) in order to work. This conversion is done via a Converter that receives the DC and changes it to an AC.
In today’s cell manufacturing technology, we can reach up to 35% conversion efficiency of the energy spectrum of light to electricity.