The PC and server power management software market is set to expand nearly five-fold by 2015, saving businesses $18.6bn and reducing energy use by more than 191 billion kWh, according to a report from Pike Research.

The report, PC and Server Power Management Software, finds that much of the power currently consumed in IT operations is wasted, and added that Idle servers, meanwhile, continue to consume more than half the power they do when fully utilised.

Servers use 60% of their maximum power while doing nothing at all and typically only run at around 15% utilisation, the report said.

Pike Research senior analyst Eric Woods said using power management settings on a single PC could save 746 kWh of electricity in just a year, which translates into savings of almost $77.

"Yet, in 2010, only a little over one-fifth of users employed power management settings effectively," Woods said.

Most companies that operate servers and data centres have more pressing concerns than energy use – namely, availability and response times, the report said.

Many different IT functions distributed across many different servers, using virtualisation software, and it is hard even to know which tasks servers are actually performing and how much power is being consumed, it added.