Miscues combine to force Colorado outages

DENVER, COLORADO - Mechanical malfunctions, inaccurate weather forecasts and inadequate natural-gas supplies caused the rolling power outages that afflicted 325,000 customers of Xcel Energy February 18.

It marked the first time in Xcel's institutional memory that controlled electrical outages occurred in the winter.

Such disruptions typically happen on the hottest summer days when demand for power peaks.

Three outages of 30 minutes each hit customers in portions of metro Denver, Grand Junction and the central mountains. The outages lasted longer than 30 minutes for about 25,000 customers.

"The phrase 'perfect storm' is overworked, but we've never seen events like this," said Xcel spokesman Mark Stutz.

Portions of three coal-fired power plants in Colorado were out of commission Saturday morning, Feb. 18, either for scheduled maintenance or because of mechanical breakdowns.

In addition, Xcel had inadequate supplies of natural gas on hand because initial weather forecasts had not suggested the record-breaking low of minus 13 Fahrenheit that day.

The utility had enough natural gas for all of its customers' heating needs, but it ran short of the fuel to supply gas-fired power generators that supplement the electricity produced by coal-fired power plants.

The gas shortage was exacerbated by an undetermined number of Rocky Mountain natural-gas wells whose pumping equipment froze, preventing additional deliveries.

The Colorado Office of Consumer Counsel will wait for a report from Xcel before deciding if an investigation is warranted, said Jim Greenwood, director of the agency that represents consumers in utility issues.

"We will follow up and try to remedy the situation if it's warranted," he said.

Xcel routinely plans several days ahead for the amount of natural gas it will need.

When Xcel began planning for the weekend cold snap, initial weather forecasts had indicated an average daily temperature of 12 degrees for the 24 hours from 8 a.m. Feb. 17 to 8 a.m. Feb. 18. The actual average was minus 3 degrees, Stutz said.

He said Xcel will investigate its weather-forecasting sources to see if better accuracy can be obtained. In addition, he said the utility will work to communicate better with customers when planned outages become necessary.