Ours doesn't go down directly based on consumption, but there is a flat fee just to be connected. So if you only use 1kwh in a billing period, your average cost is $7.10 per kwh. if you use 2kwh, the average cost drops to $3.60 per kwh. If you're using large amounts of electricity, this difference is negligible. For someone that uses very little electricity, this could actually make them be "paying" 20% more per kwh than their neighbor, just because their neighbor uses more and that flat fee is averaged out across more kwh. Taking the total bill / kwh is a *lot* easier than trying to sort out all the various costs, riders, taxes, fees, etc, etc, but can be misleading due to fixed costs. I.e., all these numbers people are throwing out aren't really good for comparing unless you're comparing similar usage. Interesting ballparking, but if someone uses little electricity, it's really going to skew things.
Keith