Imagine a spectrum of music ranging from dance-friendly, sugary sweet pop music on one end, all the way to arrhythmic noise on the other. In the realm of darktronica, synthpop would occupy the former position, and as you move down the line you would encounter EBM, industrial dance, power noise, power electronics, and finally noise. The latter two genres are too harsh to cover in much detail on this site, so the occasional noise or power electronics artist profiled here will be lumped in with power noise.
The point here is that power noise takes the aggression of industrial dance and amps it up further, using harsh feedback and distortion to produce vicious, pounding beats. Songs generally eschew vocals and lyrics, relying only on the music. Major power noise labels include Ant-Zen and Hands Productions, and to a lesser extent Tympanik Audio, Hive Records, and Hangars Liquides.