CPS Energy is the nation's largest municipally owned energy company providing both natural gas and electric service. Acquired by the City of San Antonio in 1942, CPS Energy serves more than 690,000 electric customers and almost 320,000 natural gas customers in and around the seventh-largest city in the U. S. CPS Energy bills rank the lowest of the nation's 10 largest cities, and the company has earned the highest financial ratings of any electric system in the nation. In addition, CPS Energy is top-ranked in wind-energy capacity among municipally owned utilities across the country.