I went to Tenerife a few weeks ago and saw a large group riding identical white ebikes. They looked as if they were hired. I think there a a few places hiring out ebikes there now.
I have found on internet new e-bike company in Tenerife. They called hybrid BIKES, and regards to their web this could be a real piece of electric bike to rent & climb on - www.hybridbik.es
Flagged this up originally as it seemed quite a rare E Bike, PG Bikes BlackBlock, about €5000. There were a few places hiring various e bikes then, late 2013, but didn't hire any.