headquartered in charlotte, n.c., duke energy is one of the largest energy holding companies in the united states. its electric utilities and infrastructure business unit serves approximately 7.5 million customers located in six states in the southeast and midwest. the company's gas utilities and infrastructure business unit distributes natural gas to approximately 1.6 million customers in the carolinas, ohio, kentucky and tennessee. its commercial renewables business unit operates a growing renewable energy portfolio across the united states. duke energy is a fortune 125 company traded on the new york stock exchange under the symbol duk.