a. It’s simple. Using fossil fuels like coal, oil, and natural gas to produce electricity adds pollutants to the air that are contributing to global climate change. Replacing fossil fuels with green power will help keep our air clean. You’ll be getting electricity that comes from renewable sources such as Wind, Hydro and Solar power. The ESCOs we work with purchase renewable energy via RECs (renewable energy certificates) equal to the total energy demand of their customers.