Energy Consumption Monitoring With Graph Databases and Service Oriented Architecture

CERN is a major electricity consumer. In 2018 it consumed 1.25 TWh, 1/3 the consumption of Geneva. Monitoring of this consumption is crucial for operational reasons but also for raising awareness of the users regarding energy utilization. This monitoring is done via a system, developed internally and is quite popular within the CERN community therefore to accommodate the increasing requirements, a migration is underway that utilizes the latest technologies for data modeling and processing. We present the architecture of the new energy monitoring system with an emphasis on the data modeling, versioning and the use of graphs to store and process the model of the electrical network for the energy calculations. The algorithms that are used are presented and a comparison with the existing system is performed in order to demonstrate the performance improvements and flexibility of the new approach. The system embraces the Service Oriented Architecture principles and we illustrate how these have been applied in its design. The different modules and future possibilities are also presented with an analysis of their strengths, weaknesses, and integration within the CERN infrastructure.