As energy flows from one system to another, a difference in temperature occurs, which is called thermal energy. Solar thermal energy can also be used directly for cooling, for dehumidification and for the production of hot water. This energy uses the account for a large fraction of total energy use in buildings.
- The oceanic circulation around the equator in warm water is flowing towards the poles and the colder water at the poles is heading towards the equator.
- A star’s convection star has a convection zone in which convection transfers fuel. There is a radiation zone outside the heart where plasma is flowing. When the plasma rises and the cooled plasma drops, a convection current emerges.