You answered it yourself, it’s not about day night cycle only but also about the weather. But I agree that in this particular area we can probably achieve solid innovation.
I prefer to use good ol' technologies such as power plants/damns, they are reliable, they can be done locally (most of solar panels are coming from China), they can be repaired and we can handle them country wise easily.
If we want to reduce our CO2 emissions, we move to gaz (coal -> gaz is -20%), we reduce our consumption (building isolation is -30%, sometimes -50%), and we massively reduce cars usage (by developing trains, another good ol' technology that works really well).
But if we need to reduce our CO2 emissions really fast it's one of the most efficient way to cut 1/5 of the emissions without massively changing how the grid and the other things are working.
But for sure in the end it's more a way to save time and to reduce coal usage that is also producing serious health issues to the populations.