It takes energy to run the appliances and machines we use every day. In addition to the financial cost, there is also an environmental cost in the form of carbon emissions. The general rule of thumb is that every kilowatt-hour of electricity produces 1.6 pounds of carbon dioxide. Some sources don’t emit carbon dioxide, but more than 70 percent of our electricity is produced by fossil fuels. Fossil fuels play an important role in allowing us to have lifestyles we’re accustomed to, but they do emit carbon dioxide, and we all want to be good stewards of our resources.