Replacing Distribution Transformers A Hidden Opportunity for Energy Savings

Alison Thomas, Department of Energy, Federal Energy Management Program
Michael Shincovich, Department of Energy
Steve Ryan, Environmental Protection Agency, Energy Star Program
Dave Korn, Cadmus Group, Inc.
John Shugars, Lawrence Berkeley National Laboratory

Keywords

Abstract

Electrical power distribution transformers are behind-the-scenes equipment in virtually every government and commercial building. They are energized around the clock, providing power to the building’s electrical equipment and consuming energy whether or not this equipment is operating. The Department of Energy (DOE) has replaced the aging transformers in its Germantown, Maryland, facility with high-efficiency transformers which minimize these operational losses. This paper discusses why DOE chose energy-efficient replacement transformers and also provided incremental funding for them – even though it is a tenant in this GSA-owned building. We also estimate dollar and energy savings and atmospheric carbon emissions reductions that should be realized, compared with standard efficiency transformers. To estimate these savings we evaluated transformer loading in the building.

The paper describes the load measurements and compares our results with those of other measurements in commercial and governmental buildings. These measurements reveal that distribution transformers are often much more lightly loaded than expected, creating energy savings opportunities for units with low “no-load” losses. The Germantown measurements are extrapolated to estimate savings which could be realized throughout the federal government, other levels of government, and commercial buildings nationwide through replacement with energy-efficient distribution transformers. The paper also provides a perspective on the DOE Federal Energy Management Program initiative to promote purchases of energy-efficient products throughout the federal government and the complementary Energy Star program to promote their use throughout the private sector, as well.