> Aluminum Foundries in particular are extremely power intensive and have been run during off-peak times (or are built in areas with cheap plentiful electricity like nearby hydro-electric dams).

Fun fact: this is a big reason why aerospace congregated in the pacific northwest during WWII (eg Boeing in Seattle).

Aluminum is key to aircraft because it's lightweight, and at the turn of the century the US went on a dam-building spree with a lot of hydro (ie large consistent baseload) being located in the pacific northwest.