Gloria Shae died following a blackout in the central west of NSW earlier this month.
Brian Shae said his 80-year-old mother was found deceased on the floor while attempting to reach her store of bottled oxygen on the morning of May 8.
Mr Shae said she was a registered life support customer with Origin Energy and Essential Energy when the blackout occurred shortly after 5am.
He said the company did not contact him to let him know there was a power outage in the Dubbo area.
“If there was some sort of automated system that sent out a text message I could have been there in 30 seconds,” he told Nine News.
Mr Shae said his mother was registered so the family could have more reassurance but there is nothing in place to notify next of kin in the event of a blackout.
Emergency services arrived about 15 minutes after she was found and revived her heart but Mr Shae said she was already brain-dead by that point.
Essential Energy said the unplanned power outage occurred about 5am when a member of the public reported sparks from a transformer on a power pole.
“To ensure public safety, Essential Energy remotely de-energised the local network,” a company spokesperson told AAP.
“A field team was dispatched to the site and undertook repairs so that power could be restored as safely and quickly as possible.”
The power company said supply was interrupted twice for “short durations” and fully restored about one hour after the fault was first reported.
“It is the nature of unplanned outages that they occur without notice and are of an unknown duration,” the spokesperson said.
The company encouraged customers who rely on a continuous power supply to operate medical equipment to seek advice from their medical practitioner and “have contingency plans in place”.
“But how could an 80-year-old lady whose woken up out of a deep sleep (and) short of breath manage to go out (and) start a generator?” Mr Shae asked.
Health Minister Ryan Park described the incident as a “terrible tragedy” and said he has spoken with NSW Health and encouraged energy companies to look into ways they could better support vulnerable customers.
“These type of tragic events are an opportunity to be quite blunt, to learn about what we can do better to support vulnerable customers,” he told reporters in Dubbo on Wednesday.
“I believe there is an opportunity here for energy companies to do better and I will be encouraging them to have a look at that.
“If there’s anything that we could have done differently, we will look at that.”