Did the ACT switching off power during the heatwave actually stop rolling blackouts?

As the temperature peaked at 41 degrees, the territory government asked Canberra residents to switch off unnecessary appliances and lift their air conditioning to 26 degrees to alleviate pressure on the power grid.

This was because the Australian Energy Market Regulator had predicted demand would outstrip supply across the NSW grid, of which the ACT is a part, as the temperatures soared.

While ACT electricity use during the peak time on Friday was about 15 per cent higher than the previous day, no load-shedding was required (although Mr Rattenbury said there were some unrelated blackouts in Belconnen).

"To my knowledge this is the first time this has ever happened in the ACT, largely driven by broader events in the NSW grid but I have instructed my directorate to undertake a close evaluation of how last Friday played out for a couple of reasons," Mr Rattenbury said in question time on Tuesday.

"In light of the shortfall we did ask the community to consider switching off unnecessary power needs to try and avoid that situation where there was an energy shortfall and we need to evaluate how effective that was.

"There's certainly indications across the ACT and NSW where a similar call was made that the community did respond and there was a reduction in demand and that appears to be what ensured there was not a shortfall.

"We are likely to have more extremely hot days, that is certainly the modelling for the ACT and surrounding regions so we need to look very closely on this occasion at what works, what didn't and what protocols we might put in place if this happens again."

Businesses also heeded the call to shut off power during the heatwave.

Early on Friday afternoon, the Belconnen Arts Centre decided to shut its doors immediately for the weekend to help reduce energy demand.

ActewAGL asked the Canberra Airport to power its terminal by diesel generators to relieve the grid of 1.9 megawatts of power.