My network and kWh cost are split and the network cost have risen far less than kWh cost. Also the network cost are constant. Looking at where those are used for the main cost are in peak usage capacity which efficiency actually lowers.
This would make much more sense, but if they billed by network cost I think people would quickly figure out there is no real reason to conserve electricity here. The cost of generation is so low (in fact negative sometimes) that it doesn't make a bit of difference.
