Whakakihia te rerenga e whai ake nei: I te tau 1993, i whawhai a Union Electric ki tētahi
Ko te waipuke 500-tau i te rohe taone nui o St. Louis mai i nga awa nui o Missouri me Mississippi. I te tau 1994, i tohaina e Union Electric te Tohu Edison o te umanga me Midwest Power Systems, Inc., o Des Moines, Iowa, mo a raatau mahi ki te whakarato ratonga hiko ki nga kaihoko i te wa o te aitua waipuke 1993.