Residential customers aren't the only ones stung by a string of electricity rate increases. A year ago the steel mill faced a problem businesses love -- its Roanoke plant scrambled to match production with red-hot demand. "We were going great guns right through September of last year," said Joe Crawford, vice president and general manager of Steel Dynamics Roanoke Bar Division, formerly known as Roanoke Electric Steel. "And then October hit." The minimill melts scrap metal in electric-arc furnaces and thus depends heavily on electricity. For months now, it has operated at about 50 percent capacity and tried to cut...