BEMServer vs OpenEMS

BEMServer is an open-source platform for deploying a modular building energy management system. It gathers information from building management systems and sensors alongside weather, occupant feedback, building descriptions, and contextual data. The platform connects building hardware with data-oriented services, storing building models, time series, and events for access through documented REST APIs. Its data model follows IFC and Haystack standards. Processing modules interpret collected information to identify issues or inefficient operation and support recommendations and decisions. Listed modules cover fault detection and diagnosis, renewable energy simulation, energy management, load forecasting, indoor environmental quality, and visualization. The software is licensed under AGPL-3.0, and sellers using a modified version must publish their modifications under that license. There is no software license fee, although installation, configuration, maintenance, and selected modules may be paid services. The maker recommends help from someone with Python and Docker knowledge and says installation was tested on Debian 9. BEMServer currently supports building monitoring; other uses require extending its functionality.

OpenEMS is a free, modular open-source platform for monitoring, controlling, and integrating energy storage, renewable sources, and related devices and services. Its stack combines OpenEMS Edge for on-site device communication and control, OpenEMS UI for browser and smartphone access, and OpenEMS Backend for connecting Edge systems over the internet for aggregation, monitoring, and control. The architecture supports fast PLC-like control and reusable device-independent algorithms. Integrations cover batteries, solar and battery inverters, EV chargers, meters, tariffs, and data services, using interfaces such as MQTT, Modbus/TCP, Modbus/RTU, InfluxDB, M-Bus, 1-Wire, JSON/REST, and JSON/Websocket. Edge and Backend use Eclipse Public License 2.0; UI uses GNU Affero General Public License 3. Production deployment guidance covers Debian, Ubuntu, or Docker, and Java 21 is required. Source is available online and on GitHub, with monthly releases described. The getting-started setup is intended for testing, not production.