Making assumptions again! 3Mw is a serious amount of power, as stated in the article you posted it’s enough to run 850 homes, I have no idea how much power these robots used but I know a ‘robot’ could be something huge or a small item that performs a small task maybe only using a few hundred watts.
Without knowing how much power that part of the factory uses you’re just making guesses, also when power use is low these systems feed the extra back into the grid then when the sun does go down they are buying back the electricity they already produced, their CO2 free power they fed in earlier in the day means that less fossil fuel gets burned in power stations else where. And as already discussed there have been long periods in the uk where no fossil fuel is used for electricity as there is adequate power being produced from other sources.
The only assumption I made was that they use medium sized modern, high efficiency robots. In industrial terms 3MW is a tiny amount. The smallest standard industrial power socket is rated at 16A thats 3.5kW at single phase or 10kW 3 phase. Unlike a house (which can use over 10kW peak, not the 1.5kW average implied by 850) a factory uses almost constant power.
The 2.8 kW figure I used for a robot was conservative and easily verified.
Where did you get the "entirely off solar"? is this a quote (reference please) or an assumption?
Robert G8RPI.