Ann: World-Leading Kiln Supplier to Conduct Pilot Roast Work, page-9

As you say, it is not practicable to use solar for major loads at present, but there is some progress.

Catepillar have an electric excavator:
https://electrek.co/2019/01/29/caterpillar-electric-excavator-giant-battery-pack/
Much too small for mining, but a step in the right direction.
For continuous operation, 2 or 3 interchangeable batteries could be used.

Large power needs large solar collectors.
Average insolation is 1.36 kW per sq m.
https://earthobservatory.nasa.gov/features/EnergyBalance/page2.php
So at 70% efficiency, that is about 1 kW/m2.
For each MW, that's 1000 m2.
For 24 hrs, need about 3 * 1 kW/m2 -> 3000 m2, plus battery storage for about 12 to 15 hrs, say 15 MWhrs.


The VSun CellCube is discussed in this link:
http://vsunenergy.com.au/wp-content/uploads/2016/11/Utility-Flyer.pdf