Colocation and peering provider CoreSite has settled on a target date for opening its new massive Silicon Valley data center complex. Phase 1 of the facility in Santa Clara, Calif., will come online in the first quarter of 2010, the company said Wednesday.

The phase will provide 50,000 square feet of data center floor. CoreSite plans to build two more phases in the future, each yielding about 180,000 square feet of space. The site will receive about 49 MW of power from Silicon Valley Power - the city-operated utility - at full build-out.

The company is planning to invest a total of about $350 million in building all three phases.

The data center is being built to the US Green Building Council's specifications for LEED Gold certification. It will take advantage of free cooling, 95-percent efficient UPS units, variable-speed fans, zoned lighting and other efficiency measures.

The company (formerly named CRG West) operates two more data centers in California's Bay Area region: an 80,000-square-foot facility in Milpitas and space in one of Silicon Valley's most prominent peering points at 55 S. Market St. in San Jose.