Capacity replacement is much larger in the North because of its huge existing stock of power plants and their substantial ageing. In business-as-usual scenarios with continuous reliance on fossil energy, especially coal in the United States, China, India and the Russian Federation among others, the total new capacity to be installed is almost 50 terawatts electric (TWe) or at least 12 times the current global installed capacity. Even under these scenarios, developing parts of the world would expand installed renewable capacity through 2030 equivalent to that of all power plants in the world today and half as much again as that in additional nuclear plants. The potential improvements of this installed capacity are truly huge in the developing countries alone, indicating important investment opportunities for the private sector. However, in this scenario their impact in terms of climate mitigation would be dwarfed by the expansion of traditional fuel sources. Capacity expansion refers to new power plants, while replacement capacity refers to the power plants that are built in place of those that are to be retired between now and 2030.