Lawrence Berkeley National Laboratory

Energy information systems (real-time acquisition, analysis, and presentation of information from energy end-uses) in commercial buildings have demonstrated value as tools for improving energy efficiency and thermal comfort. These improvements include characterization through benchmarking, identification of retrofit opportunities, anomaly detection to inform retro-commissioning, and feedback to occupants to encourage shifts in behavior. Energy information systems can play a vital role in achieving a variety of ambitious sustainability goals for the existing stock of commercial buildings, but their implementation is often fraught with pitfalls. In this paper, we present a case study of an EIS and sub-metering project executed in a representative commercial office building. We describe the building, highlight a few of its problems, and detail the hardware and software technologies we employed to address them. We summarize the difficulties encountered and lessons learned, and suggest general guidelines for future EIS projects to improve performance and save energy in the commercial building fleet. These guidelines include measurement criteria, monitoring strategies, and analysis methods. In particular, we propose processes for: - Defining project goals, - Selecting end-use targets and depth of metering, - Selecting contractors and software vendors, - Installing and networking measurement devices, - Commissioning and using the energy information system.