An electric meter is a device that measures the rate of electricity consumption used by a customer. It is usually installed at the point where the power lines enter your building. The electric meter records energy in kilowatt-hours (kWh).
A typical meter displays a unique meter number used to identify your consumption and displays the total electricity consumption. A meter can either be of an analog type or a digital smart meter. The former displays the total amount of electrical energy consumed and utility personnel visits the home monthly to take the reading, while the latter sends information via radio signals to the utility.
Presently, customers make use of prepaid smart meters. This simply means that the consumer purchases a certain amount of electric power from the utility and inputs the digits in the device which then converts it to energy units in kWh. Just like recharging a mobile phone, you pay before service and once the units (token) on the meter is exhausted, the power goes out automatically.
To calculate the actual energy usage, you have to add an element of time. That is, the number of watts the device consumes and the amount of time it was utilised. For instance, if you turn on a 100-watt light bulb for 10 hours, the energy usage is 100 multiplied by 10 resulting in 1000 watts which are equivalent to 1kWh. Therefore, this light bulb in question consumes 1kWh if left on for 10 hours.
Measuring your electrical energy usage would give you an approximate value of energy expenses in your home or offices monthly. It also enables you to make proper planning and utilisation of your devices.