Gas Natural México S.A. de C.V. (Gas Natural Fenosa), local subsidiary of Spain-based multinational energy corporation Gas Natural Fenosa, engages in the trading, distribution, marketing and transportation of natural gas to industrial, commercial and residential clients, as well vehicular natural gas. The company also provides energy solutions, residential gas equipment, and maintenance services. Gas Natural Fenosa's distribution network in Mexico spans 20,900km, serving more than 1.6 million clients, pursuant to 30-year concession contracts which can be extended for additional periods of 15 years. The gas distributed by the company is secured exclusively from Pemex Transformación Industrial. Areas served by the company and its subsidiaries are Monterrey, Saltillo, Toluca, Nuevo Laredo, Bajío, the North East, Sinaloa, and Mexico's Federal District. Gas Natural Fenosa also operates four combined cycle thermopower plants in Mexico —Hermosillo (270MW), Naco Nogales (300MW), Tuxpan III and IV (1,000MW) and Norte Durango (450MW)—, which began operations in 2001, 2003, 2004 and 2010, respectively. In 2014, the 234MW Bií-Hioxo wind farm came online, located in La Ventosa, Oaxaca. The company was founded in 1990 under the name Repsol México, S.A. de C.V, and it changed to Gas Natural Fenosa Mexico in 1997. The firm is headquartered in Mexico City.