A simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings

TitleA simulation-based efficiency comparison of AC and DC power distribution networks in commercial buildings
Publication TypeJournal Article
Year of Publication2018
AuthorsDaniel L Gerber, Vagelis Vossos, Wei Feng, Chris Marnay, Bruce Nordman, Richard E Brown
JournalApplied Energy
Volume210
Pagination1167-1187
Date Published01/2018
ISSN03062619
Keywordscommercial buildings, direct current, efficiency, modelica, simulation
Abstract

Direct current (DC) power distribution has recently gained traction in buildings research due to the proliferation of on-site electricity generation and battery storage, and an increasing prevalence of internal DC loads. The research discussed in this paper uses Modelica-based simulation to compare the efficiency of DC building power distribution with an equivalent alternating current (AC) distribution. The buildings are all modeled with solar generation, battery storage, and loads that are representative of the most efficient building technology. A variety of parametric simulations determine how and when DC distribution proves advantageous. These simulations also validate previous studies that use simpler approaches and arithmetic efficiency models.This work shows that using DC distribution can be considerably more efficient: a medium sized office building using DC distribution has an expected baseline of 12% savings, but may also save up to 18%. In these results, the baseline simulation parameters are for a zero net energy (ZNE) building that can island as a microgrid. DC is most advantageous in buildings with large solar capacity, large battery capacity, and high voltage distribution.

DOI10.1016/j.apenergy.2017.05.179
LBNL Report Number

LBNL-2001160

Short TitleApplied Energy