That’s correct and in line with what The Economist had reported last week (paywalled).Random post on reddit so I can't speak to the reliability but this is more or less consistent with what I've seen mentioned elsewhere.
https://www.reddit.com/r/AskEngineers/comments/3g78nj/are_aluminium_smelters_switching_to_daytime/
Aluminium smelter cells rely on running 24/7, max shut down time is around 4-6 hours before you have to rebuild the cells. Each cell is around 300k for a rebuild, there are typically several hundred at a site. Rebuild usually takes 6-9 months for the cells to get back to production after you have been down over 12 hours.
Some of the infrastructure that is being targeted/affected, like the aluminum smelters or the liquefied LNG terminals, cannot be easily repaired and restarted right off the bat.