DC nanogrid for Buildings: Study based on experimental investigation of load performance and Annual energy consumption

Abstract

Considering that most end-use electrical equipments are DC-driven, a thorough examination of the energy delivery system for buildings has become essential. Since alternate energy sources are majorly DC-based, using a DC distribution system instead of a conventional AC distribution system reduces the number of AC/DC conversion stages. This work focuses on the experimental verification of the difference in power consumption between an energy-efficient AC load and its equivalent energy-efficient DC load. Separate case studies are done for two different buildings, comprising mainly of light and fan applications. Since the consumption is majorly for light and fan applications for buildings, 48 V Extra Low Voltage DC (ELVDC) supply is most suited for DC nanogrid. The savings from DC appliances are highlighted, with a focus on actual outputs like illuminance for lights and effective wind speed for fans rather than rpm (the common practice). The energy savings and associated reduction in Green House Gas(GHG) emissions are calculated for buildings of different occupancies. If all the driving forces, viz. renewable energy agenda, loss avoidance in the distribution system and the opportunistic switch to energy-efficient appliances are clubbed together, the benefits are enormous when looked upon with the end destination as a cleaner green planet.