A recent review of an energy-efficiency system the city of Spokane bought and installed on its network-connected desktop computers has found that the system saves the city more than $14,000 in energy costs annually.

That savings, coupled with incentives from Spokane-based energy company Avista Corp., already have paid for the system, which was developed by Seattle-based Verdiem Corp., says Michael Sloon, the city's director of management information systems.

"A piece of software resides on every PC (personal computer) connected to the network," Sloon says. "It helps us manage when devices are turned off."

The city's computer network connects nearly 1,300 desktop computers across more than 20 departments in several buildings, he says.

The annual savings estimate is based on a comparison of the amount of electricity used by desktop computers before and after the installation of the Verdiem product and assumes electricity costs 7.3 cents per kilowatt-hour.

A full-year summary of the system's performance says that as of June 12, the city's desktop computers with the Verdiem system installed consumed energy at the annual rate of 397,401 kilowatt-hours, down from the baseline annual energy consumption of 598,000 kilowatt-hours prior to installing the Verdiem system.

The city paid $22,730 for the Verdiem product, called Surveyor. The price included setup, licenses, taxes, and first-year maintenance. The city, though, received a $13,000 incentive from Avista to implement the energy-saving measure, reducing the cost of the system, Sloon says.

The ongoing cost for Verdiem software maintenance is $2,800 annually, he says.

"We run audits to confirm the savings are ongoing, and the product is meeting its intent," Sloon says.

The Verdiem system can be configured remotely by the city's centralized information technology team to synchronize with each department's operational hours, because peak and off-peak computer hours vary between departments, Sloon says.

An average computer and monitor draws 120 watts when turned on, seven watts in sleep mode, and one watt when off.

In addition to automatically switching computers into sleep and off modes, the Verdiem system gathers power consumption information that IT support staff can use to adjust times that computers in each department should go into energy-saving modes.

The system also allows IT administrators to wake machines up at night to install software updates. "It enables us to do automated work after hours without having to impact employees or business," Sloon says.