Electricity can't be stored in bulk. Whatever the country switches on,
power plants have to produce at that exact moment — every hour of
every day, forever.
This page shows what the lower 48 US states actually used, and what
produced it, hour by hour.
Why it matters now: US electricity use barely moved for a
decade. It is rising again, and the power needed for AI data centres is
the most-cited reason. The Demand
by year chart is where you can see that for yourself.