Integration of a Microgrid Energy Management System in a Building Management System

Maintaining a continuous balance between energy production and consumption is essential for the reliable operation of the electricity system. The importance of managing power balance has been emphasized as the share of weather-dependent renewable energy production has increased and the share of fossil-based control power has decreased. As local consumer level production increases, so does the need for intelligent energy management. Energy management systems enable the fusion of local renewable energy sources and storages into a small intelligent and independent power grid; a microgrid. Microgrids are able to interact in real time with the operation of the entire energy system, taking into account energy market prices, weather conditions and locally forecasted energy needs and production volumes. In this thesis microgrids and energy management were studied based on the latest literature to form the starting point for an integration of a microgrid energy management system in a building management system. The thesis literature review comprehensively examined the structure of the Finnish energy system and the management of its balance, both locally and at the system level. In addition, the work focused on the areas that enable energy management in microgrids, such as the determination of the flexibility potential and the modeling and optimization of the energy system. The integration requirements were evaluated based on the use case examination and the literature reviewed. Implementation approaches were compared based on the reviewed literature. The communication between the two systems was tested with performance tests in a test environment. Communication protocols BACnet IP and Modbus TCP were selected for the performance tests, as they are widely supported in building management systems. The performance of these protocols in a automation server was measured with performance indicators specified from the automation server’s perspective. The suitability of these protocols was evaluated based on the test results. In the use case performance tests, Modbus TCP met the integration requirements with significantly lower automation server resource requirements. Based on the results, it can be concluded that the communication between these systems is straightforward to implement in a similar use case. The same implementation principles can be applied between different building automation systems as well as energy management systems. In terms of energy management, the most complex area is the energy modeling of the system and the construction of the optimization methods used to fulfill the system goals. A great deal of research has been done in recent history of optimization approaches in different microgrid use cases. Based on the literature reviewed in the work, significant benefits have been achieved with energy management and optimization. These benefits are realized locally and reflect positively to the entire energy system as the overall stability improves