Assuming you had a dream as Elon Musk, you planned to develop an economic power source of PV for oxygen production from CO$2$ for one Mar immigrant: what is the size of the PV assuming $0\mathrm{.}85$ Kg$/$day O$2$ per person and the electrochemical efficiency of aCO$2>$bO$2+$cCO is $50\%.$ HHV: CO $=12\mathrm{.}63$ MJ$/$m$3$ under standard conditions$)[10$ points$]$

you need to calculate the solar power density availability using assumptions such as a constant orbiting radius, averaging $1/3$ day with sun, $...$ PV efficiency is $10\%$ for Mars.