This high-yield structure handles the energy strains of some later, more power-intensive structures. It may cost a bit more than the original Power Plant, but it generates double the amount of power (200 units). - Command & Conquer (1995) manual
With the advent of atomic energy, nuclear power plants replaced coal power plants. Eventually, advanced nuclear power plants were built, featuring an auxiliary reactor as well as more efficient coolant system and in the First Tiberium War, formed the basis of power supply means.
After the war, GDI pursued the development of more compact, upgradeable power plants, while Nod decided to stick to reliable designs, with their advanced power plant being an efficient nuclear power plant with two additional generators, providing extra power. After the Firestorm Conflict, Nod decided to build efficient power plants with liquid Tiberium cores, which replaced advanced power plants in the role of power generation.
This power plants provides a large amount of power; a few of these are sufficient for a large base. While the advanced power plant provides double the power the basic power plant provides, it is more than twice as expensive. It does, however, save space. Power output is directly related to the power plant's condition, so commander are encouraged protect them during battles.
Advanced power plants in GDI and Nod house colours