No, it's got a mixer box (for want of a better word) in the attic that's plugged into the mains.
There's a wireless dial that talks to that, and the water itself comes from the gas combi boiler, rather than electrically heated.
I think it was this one.
Quite a bit more expensive than a regular thermostatic mixer shower, but since I was having the whole bathroom done I figured why not spend a bit extra on some nicer stuff. The labour is still the most expensive part by far.