First player need to build [[Coating shrine]]. This multiblock open access to some new material, most useful of them for know is lava-coated still that allow player upgrade their boilers.
Mv opens access to aluminum for aluminium bronze and infernal alloy. Also mv circuits, which combined with infernal alloy required to make [[Infernal boiler]], first steam producing multiblock of [[GregTech True Age of Steam]]. Player would also need [[Cooling box]] to cool maintenence fluid that is required to get infernal slug and process it into purified infernal dust.
[[Infernal boiler]] can and should be upgraded with better coils and better power hatches on the way, as it boost power production greatly.