Ann: RIU Resurgence Conference Presentation, page-7

G1A are doing similar they are using about 40% solar during day and all LNG at night - look at top left of the presentation today page 11 .
One option to increase use of solar is to do all the comminution during the day (when the sun is out) then store that ore before downstream processing at night.
Drilling cost depends on many factors one other advantage with drilling from a plat down the decline is that potentially lower cost RC drilling can be used rather than DD drilling as RC often can not go as far from surface but may go far enough if drilled say from half way down the decline .