Not extremely thick. Wire losses remain similar at 12V as they were at 110V (Replace 100W bulb with a 10W bulb at 12V, current remains ~1A so wire losses stay the same as the were). Wire losses might be say 1W for 1mm2 cabling. 240V example: https://ausinet.com.au/voltage-drop/
Agree that it is worth upping voltage to chase a few more percent savings, but still need to consider other constraints.
Not extremely thick. Wire losses remain similar at 12V as they were at 110V (Replace 100W bulb with a 10W bulb at 12V, current remains ~1A so wire losses stay the same as the were). Wire losses might be say 1W for 1mm2 cabling. 240V example: https://ausinet.com.au/voltage-drop/
Agree that it is worth upping voltage to chase a few more percent savings, but still need to consider other constraints.