The study looked at both electricity and non-electric markets. For electricity markets, some experts anticipated that due to large penetrations of variable renewables, other sources of power generation will need to be much more flexible than today, capable of load-following with high ramp up/down rates. Others believed that due to demand smoothing and increased energy storage capacities, only limited load-following capabilities will be needed. Today, nuclear power plants have the capability to load follow, though the ramp up/down rates are much less than for peaking technologies such as gas. More advanced generation III reactor designs have greater flexibility than previous generations, and utility requirements actually specify flexibility capabilities.
If the whole energy sector needs to be decarbonised, technologies that can produce low carbon heat will be required to substitute fossil-based heat. Nuclear power plants can provide both low carbon electricity and heat. The study investigated what are the cogeneration capabilities of various advanced reactor designs, as well as the flexibility they may have to switch from electricity generation to heat production depending on electricity market conditions.