FZ overall doesn't use much power. I'm powering whole early game processing in 1.6 with half of a circle of mirrors. It consists of a grinder, mixer (now 8 times faster for ore processing), 2 slag furnaces, 2 furnaces and about 40 crystalizers. Cost of mirrors is negligible in comparison to cost of furnace heaters. It was beneficial in the beginning, because it allowed for underground factorization system, which I very much appreciated (due to my dislike for griefing I exclusively choose anarchy servers when I want to play SMP). However its advantage diminished when FZ added steam and PC for 1.4.7 weren't balanced around it. Now it is also easy to get early boosts of FZ power with caliometric burner, rotten flesh is surprisingly good source of steam in water boiler.Unfortunately, PowerConvertors got a bad rep. with steam / solar abuse. That, and outputting Charge when Factorization was clearly designed much farther down the power spectrum, i.e. bypassing a huge solar setup with reflective mirrors and a steam boiler when a single early-game MJ engine or LV Solar Panel could power everything in Factorization.