A power grid alert was issued across Alberta Tuesday morning as temperatures dropped.

The Alberta Electric System Operator (AESO) issued the grid alert at 7:15 a.m., with normal operating conditions returning just over an hour later at 8:22 a.m.

The AESO said the cooler temperatures contributed to the network alert, leading to increased demand during the morning peak hours.

Three large thermal generators were also out of service and renewable energy production was low due to weaker than expected wind and the fact that solar power was not yet available.

“AESO successfully managed these conditions using established tools and processes,” AESO said in an emailed statement.

“We maintain between 550 MW and 600 MW in our contingency reserve margin when we are in our highest demand periods, and there was always a very strong supply cushion in place.”

The AESO says that although electricity consumption peaks during periods of extreme temperatures in summer and winter, the highest annual peak usage typically occurs in winter.