I'm a big fan of Factorio, but the pollution mechanic isn't well done. Its mostly an early game mechanic to encourage you to go out an massacre the natives that are inside the polluted areas. With fairly hard difficulty settings, you might start to scale back production in the early game to limit your pollution, but that's about it.
The real benefit of solar in the game is frame rate.
Also, solar is the easiest energy source to get right. Just add solar panels if you brown out during the day, and accumulators if you black out at night (or lookup/compute the solar/accumulator ratio; and lets face it, if you are playing Factorio, you probably already did). Burning fuel for power has all of the logistics problems of keeping your fuel supply saturated (plus boiler/generator/pump ratios). And nuclear can get as complicated as you care to make it.
I did a build where I really saw the positive effect of solar. I teched up to electric furnaces and replaced all of the coal driven ones with electric, including efficiency modules, powered by solar. The steam engines became used only for brown-out protection. As soon as I did that the biter attacks became much more manageable and I could easily wall in with hardly any resistence. This was on death world.
So I wouldn't say the mechanic doesn't work, for me it made a lot of sense.
The real benefit of solar in the game is frame rate.
Also, solar is the easiest energy source to get right. Just add solar panels if you brown out during the day, and accumulators if you black out at night (or lookup/compute the solar/accumulator ratio; and lets face it, if you are playing Factorio, you probably already did). Burning fuel for power has all of the logistics problems of keeping your fuel supply saturated (plus boiler/generator/pump ratios). And nuclear can get as complicated as you care to make it.