Electricity plays an important role in our lives. We depend on it every day to light and cool our homes, play our music, cook our food, dry our clothes, and stream our favorite shows on TV. Yet many of us never think about the electricity that makes our lives simpler until the power goes off. We have become so used to having electric power whenever we need it that we often take our electric grid for granted.

Our electricity is measured in kilowatt hours (kWh). A kilowatt is equal to 1,000 watts. We are charged by our electric utility for the number of hours we use a kilowatt of electricity.  The device below is a kilowatt hour light strip. We use this device to demonstrate a kilowatt hour of electricity to students. 10 light bulbs, each one being a 100-watt incandescent bulb, represents 1,000 watts or one kilowatt of electricity.  If the light strip is turned on for one hour, that represents one kilowatt hour of electricity.  This light strip provides a visual representation of one kilowatt hour of electricity.