Beginning in 2009 or 2010, electrical contractors are likely to see a new breed of higher-efficiency liquid-filled distribution transformers hitting the market, thanks to new standards expected to be announced by the U.S. Department of Energy (DOE) in September. Efficiency requirements could climb even higher in 2013, if a proposal supported by electric utilities and environmental groups is included in September’s ruling.
http://www.ecmag.com/index.cfm?fa=article&articleID=7832 Originally published in Electrical Contractor magazine, June 2007