Iran has the fourth largest oil reserves and the 2nd largest natural gas reserves in the world. The nation is a member of OPEC, and generates approximately 50% of state revenue through oil exports. Oil in Iran is a major cause of air pollution and greenhouse gas emissions. Iran also has the ability to generate significant power from renewable resources; due to the nation's closeness to the equator, 90% of its land area could provide solar power for at least 300 days a year. solar power is very underdeveloped. Iran is in a constant battle to use its energy resources more effectively in the face of subsidization and the need for technological advances in energy exploration and production. Energy wastage in Iran amounts to six or seven billion dollars (2008). The energy consumption in the country is extraordinarily higher than international standards. Iran paid 47 billion in oil export revenues, which accounts for about 50% of state revenues. Natural gas and oil consumption both account for about half of Iran’s domestic energy consumption. With its heavy dependence on oil and gas revenues Iran continues to explore for new sources of natural gas and oil. Recently Iran has focused its energy sector on the exploration of the South Pars offshore natural gas fields in the Persian Gulf.