Given the current economic/social/political environment your concerns are well founded, however I think the primary or basic problem will not be limited or unavailable [electrical] power, but rather the more pervasive and dangerous problem of a lack of spare parts, raw materials and most critical HSS and carbide tools and blanks.
Whether by design or stupidity, the American manufacturing/industrial infrastructure is rapidly being destroyed, primarily by management "outsourcing" and plant transfer.
With the trade deficit [current account trade balance] approaching 2 billion dollars *PER DAY* it does not require a degree in rocket science or a tarot deck to see that the time is near when imports by the U.S. economy will be on a C.O.D. or even a "pre-pay" basis [in gold, not dollars].
Given the U.S. has a very limited (and rapidly diminishing) domestic production capacity for machine tools [lathes, mills, gear shapers, etc.], C.N.C. controllers, and perhaps most critical M2 HSS and carbide inserts, this means the entire house of cards will collapse as the existing machinery wears out, replacements are unobtainable, and repair cannot be attempted.
Re-industrialization will be very expensive, time consuming and dangerous, as even the most basic industries such as iron foundries will have to be reestablished. Indeed, a generation or more will be required, as the evolution, techniques and lessons of the period 1890-1930 will have to be retraced, with no assurance that the time required will be available before America must again meet a serious international challenge to its existence / hegemony.