The Case for DC: Motivation of Modern Topologies, DC-Powered Solutions, and Applications within Residential Environments

The more than a century-old debate between AC and DC has its roots in an electrical distribution challenge, tackled by rival inventors Nikola Tesla and Thomas Edison during the late 1800s. Although originally collaborating on the improvements of Edison’s work, the pair eventually parted ways due to conflicts in their personalities and business pursuits. Edison’s direct current (DC) system leveraged a constant voltage and current to supply electricity, which was initially sufficient for small locales and geographical regions. However, DC encountered a major obstacle when longer-range transmission was required; there was simply no way to easily convert it between higher and lower voltages. These step-up and step-down conversions were critical for transmission, as power line losses are reduced significantly when proportionally increasing voltage levels. Tesla’s alternating current (AC), on the other hand, was readily compatible with the newly christened transformer, a device which possessed the ability to effectively adjust AC voltages on demand. With more and more entities investing into the AC-based distribution scheme, it seemed that the war of currents had been firmly decided in favor of Tesla’s solution. However, a century later has revealed an outmoded and fragile electrical ecosystem, with new energy sources and infrastructures that reposition DC as a primary contender for distribution and consumption. This paper will outline these current challenges, and explore the implementation of practical DC solutions across both the larger power grid and within residential applications