Worldwide spending on powering and cooling spinning disks used in external enterprise storage topped $1bn in 2007, according to IDC.

The analyst firm predicts that the figure will spiral to $1.8bn by the end of the year, putting pressure on IT professionals to look at more energy-efficient alternatives.

"Data centre storage requirements are growing by 50 to 55 per cent a year, but hard drive capacities are only growing by 30 to 35 per cent a year," said Dave Reinsel, group vice president for storage and semiconductors at IDC.

"In order to keep up with this growth, you either have to put in more and more drives or look for alternatives to stave off buying new drives."

IDC reported that the storage industry will ship nearly eight times the number of spinning disks between 2008 and 2012 than it has done in the past 11 years.

Vendors have moved quickly to offer solid-state server systems, and HP and Sun Microsystems have already announced solid-state options across their server portfolios.

Flash-based solid-state storage offers power-saving advantages over conventional storage technology, but is still considerably more expensive than its platter-based predecessors.

"Vendors must do more to promote and enable well-rounded green storage strategies which include data centre redesign, data consolidation and data reduction," said Reinsel.

IDC recommends that organisations striving for greener enterprise storage solutions should consider "thin provisioning" where space is allocated to servers on a just-in-time basis.