With temperatures below zero, Xcel Energy was forced to conduct rolling blackouts in the Denver Metro Area Saturday morning.
Tom Henley of Xcel said by midmorning power had been restored to the entire area, although that could change at any moment.
He said the 30-minute outages affected about 100,000 customers at a time.
He said a shortage of natural gas coming into the state in pipelines was the problem, and it affected areas served by Xcel along the entire Front Range. The only blackouts were in the Denver area, however.
Henley said customers were being asked to conserve energy, including electricity. He noted that natural gas is used to generate electricity.
At 10 this morning, the temperature at Denver International Airport was minus 4.