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 kept free jazz alive in Chicago throughout the 80s, when it had largely disappeared from the jazz landscape. 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 three more albums under the leadership of Williams.
- NRG Ensemble (Nessa, 1981)
- Generation (Nessa, 1982) - with Charles Tyler
- Conserving NRG (Principally Jazz, 1984)
- Hal on Earth (Abduction, 1989)
- The Finnish/Swiss Tour (ECM, 1991)
- The Hal Russell Story (ECM, 1993)
- Calling All Mothers (Quinnah, 1994)
- This Is My House (Delmark, 1996)
- Bejazzo Gets a Facelift (Atavistic, 1998)
- "Jazz Musician Hal Russell, 66; Headed NRG Ensemble" (obituary), Chicago Sun-Times, September 9, 1992.
- Margasak, Peter. The Undiminished Power of Hal Russell's NRG Ensemble at Chicago Reader