A demand power can be found at an electrical bill in an industry. Also, it can be found at an electrical bill in a household. In the industry the demand power is measured, and in a household this is just one more mysterious budget item at the electrical bill.
An electric meter in the industry measures average power on the define time interval. The maximum average power on the define time interval in one month is demand power for that month. The define time interval can be from 10 minutes to 30 minutes. In Serbia this is 15 minutes. A new electric meter the 15 minutes interval synchronizes with a clock.
If we in the industry take care about the demand power, we can have lower electrical bill. The goal is to have more uniformly electrical power consumption. If we have needs for peaks in electrical power consumption, we must arrange peaks in different 15 minutes time intervals. I have tried to investigate how to lower demand power at my job.