From powering kitchen appliances to leaving a light on at night to getting on the internet, electricity is at the center of many of modern life’s most basic functions. However, the cost of electricity is not fixed nationwide and running a refrigerator could be up to three times more expensive in one state than another.

To highlight how electricity costs vary across the country, 24/7 Wall St. reviewed the average retail price of a kilowatt hour of electricity in every state. A kilowatt hour, or 1,000 watts per hour, is the standard measure of electrical energy. For reference, running the average refrigerator requires 1-2 kWh a day, while running a central air conditioning unit to cool down in the summer heat requires approximately 3 kWh an hour.

Many factors can impact the price of electricity in a given area. For example, natural resources influence which fuel sources are more likely to be used to produce electricity, and weather conditions affect how much power is needed. In some areas, such factors can reduce the price of energy, while in others they may contribute to significantly higher prices.

Natural gas surpassed coal in 2016 as the largest source of energy or fuel for electricity generation in the United States. It accounted for approximately one-third of electricity generated in 2017.

Natural gas is the largest source of electricity in 16 states. Still, coal remains the largest source in 18 states. Nuclear energy and hydroelectric power are the largest source in nine and six states, respectively.

Residents of states with the highest costs of electricity do not necessarily have the highest electricity bills. In states with high electricity costs, customers compensate for the high prices by reducing their use. By contrast, households in states where electricity is relatively cheap often use more than double the electricity than homes in expensive areas.

Click here to see the states where electricity is the most expensive.
Click here to see the detailed findings and methodology.