Here’s a quick remembrance of Mr. Kilowatt at a Lorain County Nostalgia site. Ohio Edison was the power company where I grew up (not far from Lorain County, actually).
Since I spend a lot of time in the Lorain Public Library pouring over microfilm of newspapers from the 1950s and 1960s, it seems that almost every day or so there was an ad for Ohio Edison featuring — who else? — Reddy Kilowatt! I even seem to recall even seeing his image on some of the local electric utility buildings, such as up on the Ohio Edison building on Lake Avenue in Elyria Township.
There’s another Reddy sighting here, from a 1968 Cleveland Indians scorecard. Nice.