Externally, the big SUV appears largely unchanged, with a handful of blue-accented tweaks setting this green wagon apart from the regular model.
It's a different story under the skin however, with the Concept5 featuring a new version of its plug-in hybrid 'eDrive' system that pairs a turbo four-cylinder engine with a 70kW electric motor.
BMW says the combined system will hurl the X5 to 100km/h in less than seven seconds, while maintaining a combined fuel consumption figure of just 3.8 l/100km. Carbon emissions come in below 90g/km.
Like most plug-in hybrid electric vehicles, the Concept5 also boasts a pure-electric driving mode, offering a range of around 30km. The concept can also hit 120km/h without switching away from electric-only power.
The market for electrified SUVs could soon take off, with Mitsubishi's Outlander PHEV and the new Range Rover hybrid models due in the new year.
Subaru has also unveiled an electrified all-wheel-drive system, and Porsche is known to be developing a plug-in hybrid version of the Cayenne (to join the existing hybrid model).
Watch for the Concept5 X5 to debut at Frankfurt, alongside the new i8 coupe.