Demand side management in mixed residential/commercial buildings with PV on site generation

Abstract

Buildings with mixed residential and commercial units show relevant power peak that re further enhanced by shifting to electric source of nowadays gas-driven systems. The proposed solution is to organize a microgrid for such kind of buildings, aggregating different users with a common electric distribution system with a unique connection to the grid, a local common generation and a common heating/cooling system (electric-driven). This approach upgrades a group of independent several 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 load minute by minute, shifting in time plannable and controllable ones merging different kinds of load, 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 the 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 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.