Solar panels do not produce electricity when it is dark or in bad weather. This makes solar unreliable and solar plants require 100% back up all the time by fossil fuels. Battery technology doesn't exist to store even 1 day of energy in the USA.
Solar and wind require that natural gas plants, hydro-electric dams, batteries or some other form of reliable power be ready at a moment’s notice to start churning out electricity when the wind stops blowing and the sun stops shining. Read full article.
For the kinds of energy I call “unreliables”--solar and wind, whose fuel sources are intermittent, unpredictable, and most of the time unavailable, the term “capacity” is inherently misleading.
Fluctuating solar and wind power require lots of energy storage, and lithium-ion batteries seem like the obvious choice - but they are far too expensive to play a major role
