An electric 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 to measure electric energy delivered to their customers 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.
Recently, meters have been developed for granular and cloud-connected energy tracking.
This trend is helping achieve better operational performance in a number of ways. First, by monitoring the energy use of buildings, equipment and tenant spaces in real time, operators can recognize immediately when there is an issue in the building. Secondly, when it comes to maximizing energy efficiency, energy audits are only a snapshot of efficiency; meters that track energy use in real time provide continuous visibility into a property.