Strangely enough I have that pic on my harddrive without any backstory or the caption, as I own a couple cars powered by that- a Volvo b20.
Generator, then alternator was always on the passenger's side OE, even the very rare ones with P/strg and or AC, IIRC. Never owed a car with either of those, though I have the Pstrg set up in a pair of metal 5 gal pails for "some day".
Be interesting to know what required the move over to drivers.
I suppose in the Scandinavian countries a home build budget turbo set up. Ports are non crossflow and on the passenger side... so it can get busy over there... & if it were a RHD car it would make it even moreso.