Spark Energy Inc is active in the utility sector. The company provides residential and commercial customers across the United States with an alternative choice for their natural gas and electricity. The company operates through two segments: Retail Natural Gas Segment and Retail Electricity Segment. The Retail Natural Gas segment provides for most of the company's revenues and entails natural gas sales to, and natural gas transportation and distribution for, residential and commercial customers. The Retail Electricity segment consists of electricity sales and transmission to residential and commercial customers.