I find it hard to believe that MFR would have a Steam power system but no way to generate steam.
Railcraft steam boilers. I think there is a way to make steam through rotarycraft and factorization as well.
Can't vouch for RotaryCraft production of steam(not my area of expertize), but factorization has steam from solar boilers(which only work on the surface during the day, surprise surprise!), but also has a new device that "eats" food to generate heat, which can be used to heat a boiler of some kind from FZ.
GregTech has Boilers as well, too, but they aren't the most popular due to being from GregTech, even if he has a Multiblock variant that is actually really powerful.