Redstone Flux - Feed The Beast Wiki. Redstone Flux, denoted RF, is a power system introduced by Thermal Expansion.It is nearly identical in its mechanics to Minecraft Joules and serves as a replacement for them in certain mods as of Minecraft 1.6 and 1.7, most notably Thermal Expansion, but also a few others, such as MineFactory Reloaded and BuildCraft..
