The group's personnel was somewhat fluid, but included a core of drummer Steve Hunt, saxophonist Mars Williams, guitarist/trumpeter Brian Sandstrom, and bassist Kent Kessler. Their music could be broadly described as post-bop. Russell was the primary composer, but the other musicians contributed songs as well. Their punning song and album titles (Conserving NRG) reflected the humor that permeated Russell's music.
After Russell's death in 1992, the NRG Ensemble recruited saxophonist Ken Vandermark as a replacement, recording two more albums.
- "Jazz Musician Hal Russell, 66; Headed NRG Ensemble" (obituary), Chicago Sun-Times, September 9, 1992.