You may have seen an electric meter around your house or apartment building, but what do the numbers mean and how do utility companies measure the amount of electricity we use?
Electric Meters
Until recently all electric meters were mechanical devices that a utility employee had to read manually, but now utility companies use automated readers that report usage electronically. Some utility companies now even use smart meters which provide wireless access to power usage and can even monitor usage on a single device.
What is a Kilowatthour (kWh)?
Electricity usage is measured in Watts, a unit of power named after James Watts. A single watt is a very small amount of power and some devices use thousands of watts, kilowatts, to operate.
A Watthour (Wh) is the energy of one Watt used steadily from an electrical circuit for one hour. Utility providers generally use killwatthours (kWh) to measure the amount of energy a customer uses over a given amount of time. One kWh is equal to 1000 watts consumed for one hour. If, for example, you use a 60W light bulb for five hours, you would have used 300W or .3 kWh of energy.