We describe the energy monitoring system installed in the Leslie Shao-ming Sun Field Station at Stanford University’s Jasper Ridge Biological Preserve. This system, installed in April 2003, provides real-time data on the world-wide-web from 14 sensors that monitor various aspects of energy flows to and from this building. The system also maintains an extensive database of minute-by-minute data for subsequent retrieval and analysis, and regularly updates hourly, daily, and monthly summary performance graphs.