In November I observed that US electricity production had remained stagnant since 2008. Basically, manufacturing had stalled. The December 2015 decline to 95 shows a far more worrying event: manufacturing is now shrinking.
Decline of the ISM Manufacturing PMI Composite Index below 50 tends to bear this out. But a secular decline would be far more serious than your common-or-garden-variety cyclical contraction.
Does this measure of electricity production count the renewables, including domestic solar generation? Domestic solar has boomed over the last 10 years in some areas.
This is production (including renewables) by utilities. It excludes domestic solar.