I've spent some time looking at charges for my home here in the South West based upon my consumption of over 6000 KWh and I've noticed that many co's split their charges with the higher rate restricted to a specified number of KWh. The difference between the two rates multiplied by the KWh specified is effectively a 'standing charge'.
Now for something that's not altogether unrelated especially for households that have PC's running for hours on end. The demand for faster and faster machines has resulted in many PC's manufactured during the past 3 years or so having a 1/2 KW hourly consumption and that doesn't include printers, scanners, speakers etc.