One of the turbines at Iowa State’s power plant was shut down three months ago due to technical issues, forcing Iowa State to find a way to make up for the loss.

“What happened was there was a problem with one of the thrust bearings that holds the rotor blades. The bearing failed and damaged the blading,” said Jeff Witt, assistant director of utilities for Facilities Planning and Management. “This happened last November, and the unit has been out of service since then.”

Witt said the timing of the failure was interesting, since this unit was scheduled for a major overhaul in the near future.

The university power plant has four generators, including the one being repaired and overhauled.

“We just moved the overhaul up and did it now, which explains the lengthy delay in getting it back online,” he said.

Witt said the repairs to the turbine should not take much longer.

“We expect to have the unit back online the first week of March,” he said.

This scenario is reminiscent of troubles the city power plant had last year, when one of the turbines was shut down and repaired due to a technical problem. While the unit was down, the city had to buy more power.

Brian Trower, assistant director of electric services for Ames, said the amount sold to Iowa State by the city has varied greatly.

“The most amount we’ve ever sold them is 189 megawatt-hours, which was on the 24th of January,” he said. “However, there have been several periods where we haven’t sold them anything. The average amount we’ve sold to them is about 97 megawatt-hours a day.”

A megawatt-hour is the amount of energy needed to provide 1 megawatt of power – enough to light 10,000 100-watt bulbs – for an hour.

Trower said that the average household uses about 650 kilowatt-hours – 65% of a megawatt-hour – per month.

“Doing some calculations, the average amount we sold is the equivalent to about what 4,400 households use in a month,” he said.

Trower said there are other sources of electrical power willing to sell their energy.

“Let’s say that our peak capacity is 80 megawatts, but they need 110. They still need to pick up that extra 30 megawatts somewhere,” he said.

Donald Kom, director of Ames electric services, said that, even with a unit down, the process doesn’t change much.

“We have really good relations with the ISU power plant. Yes, one of their units is down, and yes, we sell power to them, but we would sell power to them anyway,” he said. “The only change is in the value of power to them and how much they buy.”