Electricity plays an important role in our daily lives. We use electricity for many purposes from lighting rooms and cooking to working appliances such as refrigerators, computers, and vide games.  However, there are about 1.2 billion people who have to live without electricity in the world. They use candles and kerosene lamps for lighting and firewood and coals for cooking. The use of those fuels has been the main reason of indoor air pollutions.  Indoor air pollution kills about 2 million people in a year.  

The table above shows electrification rate in 7 countries in 2013.  Electrification rate means percentage of people that have access to electricity.  For example, electrification rate in the United States is 100%–that means all of the people in the United States have access to electricity.