As required by the Constitution, the electricity sector is federally owned, with the Federal Electricity Commission (Comisión Federal de Electricidad or CFE) essentially controlling the whole sector; private participation and foreign companies are allowed to operate in the country only through specific service contracts. Attempts to reform the sector have traditionally faced strong political and social resistance in Mexico, where subsidies for residential consumers absorb substantial fiscal resources. The electricity sector in Mexico relies heavily on thermal sources (75% of total installed capacity), followed by hydropower generation (19%). Although exploitation of solar, wind, and biomass resources has a large potential, geothermal energy is the only renewable source (excluding hydropower) with a significant contribution to the energy mix (2% of total generation capacity). Expansion plans for the period 2006-2015 estimate the addition of some 14.8 GW of new generation capacity by the public sector, with a predominance of combined cycles. Electricity Supply and Demand Installed capacity Installed electricity capacity in 2008 was 58 GW. Of the installed capacity, 75.3% is thermal, 19% hydro, 2.4% nuclear (the single nuclear power plant Laguna Verde) and 3.3% renewable other than hydro. The general trend in thermal generation is a decline in petroleum-based fuels and a growth in natural gas and coal. Since Mexico is a net importer of natural gas, higher levels of natural gas consumption (i.e. for power generation) will likely depend upon higher imports from either the United States or via liquefied natural gas (LNG). Gross generation was 234 TWh that same year (not including cogeneration and autogeneration), with 79.2% coming from conventional thermal sources, 16.6% from hydroelectricity, 4.2% from nuclear power and 3% from geothermal sources. The expansion program contemplated by SENER for the period 2008-2017 includes the addition of 14,794 MW by the public service: 14,033 MW by CFE and 761 MW by LFC (Luz y Fuerza del Centro). Self-supply and cogeneration will add another 2,490 MW in new capacity. Total public installed capacity in 2017 is estimated at 61,074 MW, 40% and 21% of which would be combined-cycles and hydroelectric plants respectively. However, the deactivation of LFC on October 10, 2009, is likely to change this figure. In 2009, 4,000 MW were already compromised (i.e. with secured financing). The table below summarizes the projects that are currently (September 2009) under construction: Source: SENER Statistics Effective Energy Generation Source: Secretaría de Energía with data from Comisión Federal de Electricidad and