Sun is a great source of energy but very little used by our world. It currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. This energy, which can take between 10,000 and 170,000 years to escape from its core, is the source of the Sun’s light and heat.

Sunlight is a portion of the electromagnetic radiation given by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is filtered through Earth’s atmosphere, and is obvious as daylight when the Sun is above the horizon. When the direct solar radiation is not blocked by clouds, it is experienced as sunshine, a combination of bright light and radiant heat. When it is blocked by clouds or reflects off other objects, it is experienced as diffused light. The World Meteorological Organization uses the term “sunshine duration” to mean the cumulative time during which an area receives direct irradiance from the Sun of at least 120 watts per square meter. Other sources indicate an “Average over the entire earth” of “164 Watts per square meter over a 24-hour day.

For the first time, to create an electrical charge from sunlight with some materials was observed by  Alexandre-Edmond Becquerel. Though the initial solar panels were too inefficient for even simple electric devices. In 1873 Willoughby Smith discovered that the charge could be caused by light hitting selenium. After this discovery, William Grylls Adams and Richard Evans Day published “The action of light on selenium” in 1876, describing the experiment.

However, these solar panels were very inefficient, especially compared to coal-fired power plants. In 1939, Russell Ohl created the solar cell design that is used in many modern solar panels. He patented his design in 1941. In 1954, this design was first used by Bell Labs to create the first commercially viable silicon solar cell.

Each module is ranked by its DC output power under standard test conditions (STC), and typically ranges from 100 to 365 Watts (W). The efficiency of a module determines the area of a module given the same rated output – an 8% efficient 230 W module will have twice the area of a 16% efficient 230 W module. There are a few commercially available solar modules that exceed efficiency of 24%

This much cheaper and easier way to produce electricity. To date it is easy to get efficient solar panels with various rating. You can select as your demand of electricity.