Visit the frozen mountains of planet Paracelsin, where mining zinc is a race against clogging and freezing.
Mods introducing new content into the game.
New places to build more factories.
Augmented or new ways of transporting materials - belts, inserters, pipes!
Map generation and terrain modification.
New Ores and resources as well as machines.
Things related to oil and other fluids.
Furnaces, assembling machines, production chains.
I won't try and convince you that solars & accs are over/underpowered.
But why not leave the values configurable (not hidden)? This way, anyone (for example, for cross-balancing with other mods) would be able to adjust it.