Very few USA residential customers' bills include any charge for power factor, regardless of how low (less than 1.00) their power factor is. this is usually a charge to commercial or industrial classes of consumers. While some household appliances such as an aircon, 'fridge, washing machine, flourescent lights, (and, yeah, a ups) have "poor" power factors, the average for the whole service is generally about 0.8 or 0.75. However, to supply a power factor less than 1.00 requires a greater current by approx. 1/PF. This additional current causes increased wattage (which you are charged for) losses in the wiring, and the increase is by the square of the increases current level. So, you do pay extra for a low power factor. Utilities will add capacitor banks in their systems to improve the system power factor. Customers-not the utility-will add cap banks at their service entrance or at the "offending" appliance (usually a motor) to "correct" their power factor to 1.00 or near 1.00 to avoid power factor charges.