Facebook officials announced plans Tuesday to build a second data center in Prineville a year earlier than expected because of increasing demand from its users and surplus energy from its first data center, which is partially completed and already storing data.

Company officials told The Bulletin they expect to break ground Oct. 1 on the first half of a 334,000 square-foot center just west of the company’s first data center.

“We should be able to serve the West Coast once data centers one and two are completed,” said Tom Furlong, Facebook’s director of site operations. The Prineville data centers will provide new and backup data storage for centers in California and other states.