A 2008 study by the management-consulting firm McKinsey & Co. projected that the world's data centers would surpass the airline industry in greenhouse gas emissions by 2020. Certainly adding to those emissions are K-12 districts, whose data centers hold the equipment that serves as the backbone for an ever-growing number of computing initiatives. Inevitably, the dramatic rise in K-12 technology use in recent years has given way to soaring energy usage and power bills in many districts. The good news is that many K-12 school districts are recognizing their data centers as fertile ground for energy and cost savings and are taking steps to improve their energy efficiency. Not all energy-saving plans are created equal; some greening measures clearly rise to the top of the list of best practices. In this article, the author discusses five essential elements to any data center greening initiative: (1) measuring energy usage; (2) virtual servers; (3) incorporating the cloud; (4) climate control; and (5) collaboration. These essential elements may help ensure one is not missing steps integral to achieving strategic energy and cost savings. Tools for tracking energy usage and top energy-saving consolidation measures are presented.