A captive power plant is a power plant owned by an factory for its own power consumption. That is, all the power generated in the captive power plant is consumed by the factory itself.
Many industries such as textile units, cement factory and petrochemical industries require cheap and reliable power. The utility may not always meet their needs. Hence, they set up their own power plants. These plants do not supply power to the grid.
These plants are mostly less than 50 MW.