Duke’s problem shows what happens when basic science collides with operational reality. Solar energy is intermittent. Until a reasonable storage technology is available, natural gas plants must operate when solar is brought on and off the grid. Put simply, the gas plant is generating power when the sun isn’t shining. Duke’s applications reportedly show that, due to the see-saw effect of deploying solar, emissions of the pollutant nitrogen oxide have increased, even though the level is lower than emissions from purely coal-based energy.
North State Journal also reported on Duke’s concerns about the potential reversal of reductions in another pollutant, carbon dioxide, if North Carolina continues to impose its renewables mandate on utilities. Such a reversal is possible if regulations force Duke to reduce nuclear plant output because it must accept solar electricity instead. It turns out that when...