Impact of nuclear energy on fossil fuel substitution

Abstract

A viable strategy to reduce the global carbon dioxide emissions is the substitution of fossil fuels with non-carbon sources for electricity generation. Because wind power is intermittent and solar irradiance is periodically variable, the capacity factors of renewable units are significantly lower than those of fossil fuel units. As a consequence, the needed installed capacity for wind and solar units is higher than the capacity of the fossil fuel power plants to be substituted. In addition, energy storage becomes necessary to satisfy the fluctuating demand of all electricity grids. Nuclear energy will assist with this substitution, because nuclear power plants generate continuously and exhibit capacity factors very close to 100%. Using data for the hourly power demand and supply in a large electricity grid, this paper examines the effects a nuclear-renewables mix will have on the electricity generation industry. It is determined that the addition of some nuclear generating capacity decreases by a factor of approximately 3 the required wind capacity and by a factor of 6 the required solar installed capacity. The contributions of nuclear energy also result in reductions of the dissipated energy in the storage-regeneration processes and the needed utility-level storage capacity.