120/240V wiring is rated for 10% loss at max ampacity.
Thus for 12V wiring with CC drivers, choose 10x ampacity rating .
If using CV drivers, then higher ampacity wiring or losses must require high source voltage.
Ideal solution is trickle charge from PV to small lead acid battery near load with 18Voc PV and float voltage at 14.2V with load voltage ranging from 12.5 to 11.5V for 100 to 10% SoC.
Four 1A Toshiba white LEDs with 140 lumens /W in series operate down to 2.5 x4=10V when dim.
Up converter to down converter from DC to AC will result in more cost and losses than adequate ampacity cables, unless you are driving > 100m with > 10kW, I think.
Express your requirements in kW- meter (power x distance) to evaluate the costs vs efficiency.
If you prefer LiPo batteries choose string size of LEDs to match LiPo string.
Poor LEDs are 3.3-3.7V @1A Good ones are 2.9-3.1V and LiPos are 3.7-3.3 on discharge and 4.2 on max charge, which gives enough headroom to make an ultralow LDO buck LED driver or simply diversity switch, 4.2 max during daylight and 3.7Vmax in dark per LiPo cell and thus drive LEDs with 0.3 to 0.7 Ω cable direct to LEDs such as a 3.7x4= 14.8V which drops to 3.3x4=13.2V when dim during 4 LED direct from lossy long wire.
Matching wire resistance near total ESR of LEDs is key when choosing optimal efficient good CV battery drivers. This would not apply to alkaline. See my other thread entries on this subject.
