People cranking up their air conditioners this week have put some strain on the Austin Utilities Company.

A peak alert was issued Monday and Tuesday in Austin. Over those two days Austin Utilities ran messages across television screens, asking customers to shut off unused appliances and turn up the thermostat to help conserve energy.

A peak alert means the city is approaching the highest level of usage based on the top temperature from previous years. If that peak is surpassed, Austin Utilities would be forced by law to purchase more energy the following year, regardless of the likelihood that it would need to be used.

General Manager Jerry McCarthy said exceeding that usage level could mean higher costs the next year.

"It gets expensive, so we try to control that as much as we can," he said.

Besides messages to the public, another way they are controlling the usage is through a load-control system. Eight power grids control the energy to all of the air conditioners in the city. The utilities company switches off first one power grid for 5 to 7 minutes and then the next, in a consistent rotation.

McCarthy said they have been using that system for about 12 or 13 years, and most people do not even realize it is happening.

Employees at Austin Utilities are doing what they can to conserve energy as well.

"As I sit in the office, all the people are walking up and down in a dark hallway," McCarthy said. "We do our part too."

He said if the residents of Austin make sure to use only what is necessary, there should not be a problem.

"We really do appreciate any support the community can give us," he said.

Matt Merritt can be reached at 434-2214 or by email at matt.merritt@austindailyherald.com