Emergency tanks are good. I have 4. We also have a generator. Tanks only last abt 1hr (mine do anyhow at 3lit / min.

I have an emergency tank in my home but I'm not sure how long it will last and I have neighbors on oxygen and our building is all electric but I'm blessed to have siblings living about 10 minutes away and I can drive so I will be able to manage but I have neighbors that are alone here and don't have personal transportation and the power door locks on the main entrance unlock if we lose power and it is very disconcerting and dark outside. I'm of the opinion that the people who own the building are only concerned with their money and they don't give a hoot about the tenants that pay to live here.

When power goes out it turns on itself

We had a Generac put in. Was really expensive. Connected to our gas line in house. The Generac is out side. Nancy6

If you rely on an electric concentrator, be sure the unility company knows that you need electricity for 02. Your DME should be able to give you tanks enough for 24 hours without electricity; more than that and you should talk with your emergency management people to help you devise a plan about where you'll go. Usually the local fire department or hospital can provide 02.