AC Versus DC Distribution SystemsDid We Get it Right?

We presently enjoy a predominantly AC electrical distribution system, the engineering basis for which was designed over 100 years ago. While AC distribution systems have served us well, we should periodically pause to assess what opportunities we have accepted or been denied by the overwhelming predominance of AC electrical power distribution systems. What opportunities could be obtained by engineering DC distribution into at least portions of our present system? What advantages of the present AC distribution system should be recognized and protected? This paper will focus on distribution within premise and low-voltage distribution systems. Specifically, we will address the conversion efficiency costs of adopting various premise AC and DC distribution system topologies. According to a simple predictive model formulated in this paper, premise residential DC distribution will incur unfavorable total conversion efficiency compared with existing AC premise distribution. However, if a residence is supplied by a fuel cell or another DC generator, the total conversion efficiency within a residential DC distribution system could be similar to, or even better than, that for AC distribution.