Southern is one of the largest utilities in the us. The company serves 9 million customers with vertically integrated electric utilities in three states and natural gas distribution utilities in four states. It owns 50 gigawatts of rate-regulated generating capacity, primarily for serving customers in Georgia, Alabama, and Mississippi. Subsidiary Southern Power owns 13 gigawatts of natural gas generation and renewable energy across the U.S. and sells the electricity primarily under long-term contracts.