The North Carolina data center that Apple has touted as especially earth-friendly (for having biogas-fueled generators, for one thing) will soon have a smaller companion; Apple is expanding its presence, according to filings reported over at Slash DataCenter, with another 21,000-plus square foot facility at the same site. "Apple also plans to build a hydrogen fuel-cell facility in the area, at least based on other filed permits. That would complement the solar-array installations under construction. Apple has claimed that some 60 percent of the data center facility’s power will be generated onsite. As it stands now, the Maiden facility already incorporates energy-efficient design elements, including real-time energy monitoring and analytics."