Solar energy is the energy that is in sunlight. It has been used for thousands of years in many different ways by people all over the world. As well as its traditional human uses in heating, cooking, and drying, it is used today to make electricity where other power supplies are absent, such as in remote places and in space. It is becoming cheaper to make electricity from solar energy and in many situations it is now competitive with energy from coal or oil. A solar cooker can be used for cooking food. Solar energy is also called "Heat Trapper" as it is the automatic, non-mechanical, sun ray trapper. This Sun trapper like devices were used by soldiers during WWII for heat requirements in the army and enemy directions.