Those things aren't going to zero anytime soon.
https://hackaday.com/2019/08/22/electric-dump-truck-produces...
Furnaces have been run off of solar (parabolic mirrors) for quite some time.
I wonder if a process similar to that used for molten salt batteries, using reflected, concentrated sunlight, could be used to melt sand into what is needed for more solar panels, electronics etc, and use the stored energy while it cools off, essentially combining the processes? And of course for other [s]melting processes powered by fossil fuels today?
Hmm, after doing a bit of research: the melting point for saltpeter (used in molten salt storage [0]) is only 550°F, while silicon's is 2,577°F... would a reflecting solar array be able to reach those temperatures? If I'm reading this [1] correctly, you could only practically get to 3,698.33°F (really close to your example of a 1,800°C furnace) if you collected all the sunlight falling onto earth. It's got to be much worse than that though in practice, because to focus all of it onto a single point would require beaming reflections from the perimeter a long distance through air, and also around the curvature of the earth...
So, we need to build this on the moon or in orbit? Oooh, Futurama actually showed us what could go wrong here [2].
[0]: https://en.wikipedia.org/wiki/Solar_thermal_energy#Molten_sa...
[1]: https://en.wikipedia.org/wiki/Concentrated_solar_power#Ideal...
"Silicon processing: from quartz to crystalline silicon solar cells"
https://www.pyrometallurgy.co.za/Pyro2011/Papers/083-Xakalas...
What other things do you think are never happening that are infact already happening?
But what is wrong about what I stated? It's obviously impossible for solar to approach $0 because of the large material costs inherent in manufacturing solar panels and transporting electricity. This is not contrarianism, it's realism. We probably use more energy per capita than is sustainable, and eventually we will have to change that.
Also solar panels wear out. I could see a case being made for the cost going to zero if you amortize it, but you can only amortize it over about 25 years, after which you have to replace the panels. This sets a floor on the price.
They're slow-moving, inherently massive and heavy, and travel relatively short distances per round-trip. So they don't care much about battery weight, size or limited range, and appreciate the massive torque from low RPMs.
It's kind of an ideal case for a battery-swapping BEV system. Just wait for the battery costs and energy densities to both improve and this will be a no-brainer. They can charge the drained battery on the grid from cheaper/cleaner sources while the other is busy hauling a load.
Of course if the terrain is such that the mine is on the top of a mountain ascended empty but descended full, you don't even need battery swapping, it'll recharge on the descent.
Nobody wants to spend money owning and operating those diesel engines if they don't have to. When the BEV option is available and makes business sense they'll switch immediately. They'll require little maintenance, and you don't need specially trained technicians to swap batteries and order new ones when they need replacing.
1) mines run on a 24/7 schedule. There is not enough down time to charge batteries in a shift and with how completely filthy machines get we need better solutions for battery swapping in mining before that becomes an option, and
2) because (like the mine I am at right now) a non-negligible number of mines are far from grids or clean power sources, a lot of battery power would come from fossil fuels burned near the mine.
There is interest, but most of the actual use seems fairly superficial (public image boosts).
What economics would it take for your mine to have its own solar or nuclear powered microgrid. What about when fossil fuel supplies are unreliable or interrupted.
For near zero? Where?
Not with that attitude