Intermittent variable renewable energy (see Part I) generation sources are primarily wind turbines and solar photovoltaic panels (solar PV). But they can include underwater-based turbines (“tidal”) and solar collectors (“mirrors”); large-scale lithium-ion battery storage facilities (“batteries”); and electric facility-stored fuel (water/hydro, oil, coal, natural gas, or nuclear energy), to be turned into electrons when needed, since these fuels can be stored at less cost than electrons.
Storing fuel and converting it into moving electrons (electricity), with the exception of planned maintenance (relatively rare occurrences) and unplanned outages (even rarer), most generators were designed – and, more importantly, costed – to operate at a fairly steady state. This steady state is commonly called, baseload energy. When a baseload generation facility is pumping out all the electricity it can produce, it operates in a steady-state, which is good for its design life as well as maximizing revenues against costs for maintaining high performance and attracting more of the same to meet demand growth.