Yesterday there was a system wide outage which meant that power was out in the Alice Springs region for much of the afternoon and into the night.

Temperatures rose to almost 40 degrees during the day.

Crews responded immediately and critical power was initially restored to priority areas including Alice Springs Hospital.

Power was completely restored at approximately 10.47pm.

An investigation into the cause of the network outage is underway.

"I have made it clear to the CEOs of Territory Generation and Power and Water Corporation that this is unacceptable," Renewables, Energy and Essential Services Minister Dale Wakefield said today.

"Territorians deserve a stable and secure power system, and that is why I have called for an independent review into this incident."

The independent review will identify and investigate any system wide issues that led to this problem occurring and the adequacy of responses, both short and long term.

Electrical Trades Union members in Alice Springs today criticised TGen as the town of 30,000 was again plunged into darkness on Sunday.

The blackouts which affected most of the town lasted for up to 9 1/2 hours could have been mitigated or avoided altogether the union says.

ETU Territory organiser Dave "Strawbs" Hayes said the union and its members have been proactive in telling TGen management that their systems were not fit for purpose and that they needed to have Ron Goodin Power Station (RGPS) on active standby for exactly these eventualities.

"The guys on the front line live and breathe this stuff and they have been saying for months that RGPS was prematurely closed and that Owen Springs was not adequately tested to ensure continuity of supply. They have been urging TGen to complete required maintenance on RGPS to keep the generator on active standby. These requests have been denied and instead of facing a blackout extending minutes at worst residents had to endure up to 9 1/2 hours in uncomfortable heat. It's not on, TGen managers are playing Russian roulette with people's lives." Mr Hayes said.

Further, the union called for local Alice Springs ETU members to be included on the government's investigation panel, to ensure it does not end up as a sham.

Union members also demanded;

While you're with us, you can now receive updates straight to your inbox each Friday at 6am from the Katherine Times. To make sure you're up to date with all the news, sign up here.