An electricity meter, electric meter, electrical meter, or energy meter is a device that measures the amount of electric energy consumed by a residence, a business, or an electrically powered device. Electric utilities use electric meters installed at customers' premises for billing purposes. They are typically calibrated in billing units, the most common one being the kilowatt hour (kWh). They are usually read once each billing period. When energy savings during certain periods are desired, some meters may measure demand, the maximum use of power in some interval. "Time of day" metering allows electric rates to be changed during a day, to record usage during peak high-cost periods and off-peak, lower-cost, periods. Also, in some areas meters have relays for demand response load shedding during peak load periods.
“I was walking through the hardware store the other day and I walked past an energy meter which clips onto your home’s electricity mains and then provides you with information on your power consumption and cost estimates for the …
“The Peacefair PZEM-021 energy meter is very popular and super cheap at ebay - the unit is very good and usefull for all sorts of projects and to be used when working with mains powered electronics. This energy meter is …