DC Local Power Distribution: Technology, Deployment, and Pathways to Success

Direct-current (DC) power distribution has been used ever since electric grids were invented, but, for the last century, low-voltage dc has been largely limited to a variety of niche applications such as rail transport, vehicles, telecommunications, and off-grid buildings. Recent years have seen a variety of innovations in dc distribution technology, notably, standards for 380-V dc cabling and connectors and increases in power that can be carried over Ethernet and universal serial bus (USB). There are increasing calls for much more use of dc distribution and dc microgrids in buildings, and there are potential advantages of both. However, open questions remain about the directions this might take, what policy makers could and should do in this area, and technology developments that would be most useful. This article considers potential pathways for increased use of dc and identifies those pathways that seem most beneficial and likely to succeed. We limit the scope of consideration to distribution within (or between) buildings.