Well we heard the turbine spin up today...not hugely fast but generating a few watts nonetheless.
It emits a whirring sound, certainly not intrusive, but definitely noticeable. I only heard it when outside the bus...I will make a point to listen inside the bus next time.
When I get a chance I'll do a short video and post it.
Soused Moose---feel free to use any pictures and/or text from my website on your storefront.