Expert assessments on the future of direct current in buildings

Increasing adoption of distributed generation, improving power electronics, and growing electronic loads in buildings have led researchers to propose increased use of direct current (DC) power distribution systems in buildings. As these systems have proven safe and reliable in other applications, they are now being considered for more widespread use in commercial and residential buildings. But nontechnical obstacles remain that have not been addressed in the technical engineering and economic analyses conducted thus far. In this paper, we report on an expert elicitation of 17 experts from industry, research organizations, and the implementation or operation of DC systems to better understand the biggest nontechnical challenges to deploying these systems more broadly. Because these challenges vary based on location, the focus of this study is on the United States of America. Results show that the two biggest barriers are industry professionals unfamiliar with DC and small markets for DC devices and components. To address these, experts proposed developing training programs for engineers and electricians, and developing pilot projects to prove the benefits of DC in niche applications where DC power distribution holds a clear advantage over AC Experts also identified lasting and inherent benefits of DC that make these systems better suited to serve future building loads. These include their ability to interface with distributed generation and onsite DC generation sources such as solar photovoltaics, as well as their ability to communicate and supply power over a single distribution line. Finally, experts identified research priorities to make a better case for what appears to be a promising technological solution to safely and reliably powering future buildings.