It was written and produced by production team The Runaways, consisting of Louis Biancaniello, Sam Watters, Rico Love, and Wayne Wilkins, for her studio album In a Perfect World… (2009).

A midtempo power ballad, "Energy" talks about an overwhelming and consuming toxic love that is causing the protagonist to reconsider her priorities.

[6] Nick Levine from Digital Spy found that "despite its glistening production, this synthy R&B ballad falls into the solid but unspectacular category.

"I don't want us to be the end of me, this love is taking all of my energy," Hilson sings on the chorus, but her vocals are a little too controlled to convey these anguished emotions.

"[7] Billboard's described the song as a "midtempo power ballad showcasing Hilson's range and soul [...] The Runaways provide a catchy hook.

"[9] BBC Radio 1 editor Fraser McAlpine compared the song "Apologize" by American band OneRepublic and "Battlefield" by singer Jordin Sparks.