Combined cycle plants are the best option from among the traditional fossil fuel generation alternatives as they are secure and reliable and have a limited impact on the environment. Gas Natural Fenosa has 11,891 MW of installed power in natural gas combined cycle plants, divided between Spain, Mexico and Puerto Rico. In 2013, Gas Natural Fenosa produced 67% of its electrical energy through combined cycle plants. The installed power for this technology is located in Spain (6,998 MW), Mexico (2,035 MW) and Puerto Rico (263 MW). Combined cycles, which use natural gas, are more efficient and cleaner than conventional fossil fuel plants, as they don't release sulphurated compounds or particles into the atmosphere and their CO2 emissions are 60% lower than those of conventional thermal generation. Furthermore, they only consume a third of the water that other plants require to operate.
Due to the characteristics of this energy, it is one of the best solutions for achieving a low carbon economy. In Spain, combined cycles play a decisive part in developing non-manageable renewable energies, such as wind energy, due to their role as a back-up. Combined cycles are more efficient than other traditional thermal technologies like coal and fuel as they produce energy in two phases. During the first phase, they generate electricity through the direct combustion of natural gas. During the second phase, they use the residual gases, which are still warm, to generate water vapour that moves a turbine and produces more energy. The combination of two systems increases the efficiency of the process by up to 55%-60%, compared to 30%-40% for other thermal technologies.