On September 7, 2012, at 10 a.m., after playing "What Might Have Been" by Little Texas and the first minute and a half of "The Thunder Rolls" by Garth Brooks (which began repeating on the line "When the thunder rolls/and the lightning strikes..." before grinding to a halt that led into energizing sound effects featuring thunder and lightning), WZBK finally flipped to Rhythmic Top 40, branded as "Energy 106.9". "Energy" launched with "Party Rock Anthem" by LMFAO. In a statement from general manager Annmarie Topel, the station's format will be similar to a contemporary-hits format, but with "no bubble-gum pop," and added that "As the (rhythmic CHR) format evolves, there are great opportunities for stations that are newer, faster, cleaner and leaner." On September 12, the call letters were changed to WNRG-FM. (Despite this, WNRG-FM continued using the WZBK legal ID liners for two more days.) In its first 30 days, WNRG was commercial free and promised to play 10,069 songs until October 8, when it added commercials and began promising to play 60 minutes of music per hour on air.