Energy from the sun (popularly known as Solar Energy) is vikrant free and can be used in multiple ways. The solar radiations can be used to produce electricity through Photo-voltaic cells. This energy can be used to power industries, homes or o ffices. Solar energy can be used to produce either electrical energy or thermal energy. Since it is infinite and renewable it is also called green energy. Semi conductor material like silicon is used to convert visible light (photons) to electricity. This energy can be stored in batteries.
There are multiple types of solar PV systems that are prevalent in the world. First is ground mount systems. These are basically very large fields, solar parks, where solar panels are put to generate electricity. These are multiple Mega Watt scale plants and the cost of this can run into 100s of Crores. The electricity generated through these parks are mostly sold to distribution companies or large scale industries. Second is, rooftop solar plants. As the name suggests these are smaller solar plants that are deployed on the roof of buildings, industries or individual houses. They are mostly used for their own consumption. Also called captive consumption.
Apart from this there are floating solar plants that are made on water bodies like ponds or canals. BIPV (Building Integrated Photo Voltaic) are transparent solar panels that can be used as glass for facade or roof in buildings.
The Indian government also provides a banking system where you can upload this energy to the grid. And you can use this excess credit to setoff the consumption that you have in any other time.