DC Lighting and Building Microgrids

Direct current (DC) electricity has the potential to improve the resiliency, reliability, and energy efficiency of building systems. DC facilitates the ability to more easily and directly connect renewable resources such as solar photovoltaics (PV) and energy storage batteries to DC building loads such as light-emitting diode (LED) lighting, computers and electronics, electric vehicle chargers, and variable-speed heating, ventilation, and air conditioning (HVAC) equipment. The improved efficiency of the combined technologies can result in an estimated 10–18% in energy savings.1 When configured as a microgrid, PV systems and batteries can power DC building loads in the event of a grid outage, improving the resiliency of homes and businesses. Despite the myriad benefits and opportunities provided by DC, its adoption in the market has been slowed by both the lack of available equipment and standards and the challenge of overcoming the status quo of building electrification.