GESE: Granular Electric Sub-Metering Economics in the Context of Automated Demand Response

Granular electric sub-metering is a key component of progressive building operations. It enables use cases including: electricity and carbon accounting, tenant or departmental billing, measurement and verification for energy conservation measures, and fault detection and diagnostics. It also enables emerging practices like predictive maintenance, occupancy detection, and Automated Demand Response (ADR). This paper compares 3 design patterns that elevate a sub-metering system to an ADR capable system to determine if networked smart plugs and breakers facilitate ADR at a lower cost than traditional building automation system (BAS) equipment. We consider the requirements of our ADR systems to be: knowing real-time energy consumption and being able to programmatically switch loads or branch circuits. We also experimentally validate the accuracy of lower-cost metering solutions. We find that smart plugs are not meaningfully less accurate than traditional power meters. We find that while smart breakers are less accurate than smart plugs, they are accurate enough to be used for informational purposes. We find that the infrastructure required to deploy an ADR solution on top of either a smart breaker or smart plug based metering system has fewer components is likely less expensive than an ADR system based on a BAS architecture. In conclusion, we find that IoT-style smart plugs and breakers offer a viable and relatively low cost alternative to traditional BASs for the purpose of ADR. However, because of the limitations of switching loads entirely off, the useful application of this approach may be limited to residential settings.