It is apparently the Chester Power Plant, Chester PA.
http://www.peleast.org/RR_Fall_2002/14_chester.pdf The architectural details match, and that plant was converted to offices.
Found whack of vintage pictures of the plant here: http://lcweb2.loc.gov/cgi-bin/query/r?ammem/hh:@field(NUMBER+@band(PA3680))
[This message has been edited by classicsat (edited 03-27-2005).]