Aggregation of users in a residential/commercial building managed by a building energy management system (BEMS)

Buildings with mixed residential and commercial units show relevant power peak that are further increased by shifting from gas-driven systems to electric source. The proposed solution is to organize a microgrid for such type of buildings, aggregating different users with a common electric distribution system with a single connection to the grid, a local common generation and a common heating/cooling system (electric-driven). This approach upgrades a group of independent small users with rigid loads and chaotic behavior, to a large user with a flexible and controlled profile. A central building automation control system (BACS) managing all built-in technical systems and smart appliances may control the load minute by minute, shifting in time shiftable and controllable loads and merging different kinds of loads, obtaining a flatter diagram. The authors consider the suggested approach convenient to realize demand side management (DSM) for residential/commercial buildings. DSM exploits the flexibility of smart appliances and the thermal inertia of the structure, by imposing local and central set-points of heating and cooling systems according to actual global net load and generation at a given moment. In the present paper, main aspects of the proposed control system are presented and simulations for a given case study with local PV generation are provided. Results show that this approach may lead to a power peak reduction up to 20% even in the unfavorable case of combining commercial and residential units. Moreover, full self-consumption of locally generated energy from RES may be achieved.