Basin Electric Power Cooperative might have hit its peak electricity usage twice in one week, but it will take a few weeks to verify that, Daryl Hill, a spokesman for the company, said Thursday.

Hill said company officials believe the peak of 1,554 megawatts set in July 2004 was surpassed Saturday and again on Tuesday when temperatures broke the 100-degree mark in North Dakota.

The high usage did not cause power disruptions and did not require Basin to operate any peaking plants.

"We still have the capacity to serve the needs of our members," Hill said.

Peaking plants normally run off of fuel oil or natural gas and are designed to run for a short period of time during times of high electricity use. Most of the company's electricity is produced from coal.

Basin Electric, based in Bismarck, owns 2,499 megawatts of electricity and operates a total of 3,412 megawatts of electric generating capacity. Basin Electric serves 1.8 million people in nine states.

Hill said that although the peak was weather-driven, other states didn't have temperatures as high as North Dakota. Cooler weather in other states that Basin serves helped keep usage down far enough so that peaking stations were not needed.

Hill said air conditioners and irrigation systems are the two main sources of electricity usage during the summer.

Montana Dakota Utilities Co., also based in Bismarck, did not hit peak usage, company spokesman Dan Sharp said.

Sharp said the last time the company hit a peak was two years ago, when 472 megawatts of electricity were used in a day.

Sharp said nighttime temperatures have been cool enough to prevent a peak.

"What it takes for a peak is a warm evening followed by a hot day," Sharp said.

Montana Dakota Utilities Co. provides electricity and natural gas to customers in five states.

Although electricity use increases in the summer, the price of electricity is stable in the short term.

Hill said Basin, which is a nonprofit company, sets its rates periodically and sometimes returns revenue to its customers. Basin is not regulated by the Public Service Commission.

Montana Dakota Utilities Co., which is regulated by the PSC, has to receive approval for rate increases.

Sharp said electricity rates are usually stable for several years and that an increase in price requires a lengthy process.

(Reach reporter Tom Rafferty at 223-8482 or tom.rafferty@bismarcktribune.com)