I have recently started work for a small company that, amongst other things, resells and installs Power Factor Correction equipment. The customers are small medium businesses who consume over $ 1000 of power per month.
I have only just started studying Power Factor correction. I am not an electronics engineer.
We have just over 200 installed sites for a small scale Automatic Power Factor corrector.
A few of these customers are billed in kVA. There appears to be no question that p.f. correction saves kVA.
Most of our customers are small, and so they are billed in kWh. They do not care about kVA savings.
My boss, and the company, claims that, on average across all kWh billed customers, the device we install saves around 15% of kWh. This claim is supported with (a few) graphs of individual customer's kWh usage comparing kWh prior to installation of the p.f. correction device, with kWh post installation.
The problem I have, as has also been posed here in this thread, is that having looked at dozens of web sites and technical bulletins that discuss power factor, almost none of the theory discusses p.f. correction as being able to bring kWh savings.
Yet, our firm's experience, and the few pieces of individual customer analysis of power bills, indicates that p.f. correction does, for consumers who are billed in kWh, bring kWh savings ranging from 10% to 20%.
I would like to understand how this can be?
The only explanation I can think of is that an appliance with a low p.f. (say 0.6) must need more kWh than the same appliance needs once the p.f. corrected (to say 0.95).
Does anyone have anything to add (or detract) from this rationalisation? Can someone point me to some science which discusses kWh savings from p.f. correction?
Scott.