Where UK hard house has uplifting, playfully fun and tough elements, NRG is ominous, dark, aggressive and relentless with its distressed, menacing and gritty sounds on a slightly faster BPM (155–165 average) than UK hard house (150–155 average).
[3] Acid house of the late 1980s was the 'happier' (playful/fun) side of dance music exemplified by Italian piano-house (Italo disco/hi-NRG of the early 1990s) and this began to progress into a scene of its own.
By the mid-1990s, uplifting house music in this vein was in abundance and producers in the UK such as The Sharp Boys were providing their own interpretation of the sound.
Hard house as a style was epitomized in the early days by producers such as Paul Janes, The Tidy Boys, Pete Wardman, Steve Thomas, Ian M, Alan Thompson, Captain Tinrib, DJ Ziad and Tony De Vit.
By 1996–97, there was a steady flow of UK-based hard house that threw away the fun and uplifting parts to incorporate the "Hoover" and other gritty, menacing sounding elements at a slightly higher tempo than the conventional hard house and thus, the style effectively became known as "nu-NRG" when Blu Peter coined the phrase in a magazine interview.