generation; rolling blackouts are implemented as necessary. The unreliability of the electrical supply has hindered the development of Tanzanian industry. In 2013, 49.7 percent of Tanzania's electricity generation came from natural gas, 28.9 percent from hydroelectric sources, 20.4 percent from thermal sources, and 1.0 percent from outside the country. The government is building a gas pipeline from Mnazi Bay to Dar es Salaam, with a scheduled completion in 2015. This pipeline is expected to allow the country to double its electricity generation capacity to 3,000 megawatts by 2016. The government's goal is to increase capacity to at least 10,000 megawatts by 2025. Natural gas According to PFC Energy, 25 to 30 trillion cubic feet of recoverable natural gas resources have been discovered in Tanzania since 2010. The value of natural gas actually produced in 2013 was US$52.2 million, a 42.7 percent increase over 2012. Commercial production of gas from the Songo Songo Island field in the Indian Ocean commenced in 2004, thirty years after it was discovered there. Over 35 billion cubic feet of gas was produced from this field in 2013, with proven, probable, and possible reserves totalling 1.1 trillion cubic feet. The gas is transported by pipeline to Dar es Salaam. As of 27 August 2014, TANESCO owed the operator of this field, Orca Exploration Group Inc., US$50.4 million, down from US$63.8 million two months earlier. A newer natural gas field in Mnazi Bay in 2013 produced about one-seventh of the amount produced near Songo Songo Island but has proven, probable, and possible reserves of 2.2 trillion cubic feet. Virtually all of that gas is being used for electricity generation in Mtwara. The Indian Ocean, off the coast of Mozambique and Tanzania, is proving to be a rich hunting ground for natural gas exploration. According to US Geological Survey estimates, the combined gas reserves of Mozambique and Tanzania could be as high as 250 trillion cubic feet. In Mozambique alone, proven gas reserves have increased dramatically from a mere 4.6 trillion cubic feet in 2013 to 98.8 trillion cubic feet as of mid-2015. Given continued offshore discoveries and the size of discoveries to date, continued growth in proven gas reserves is likely to continue into the foreseeable future. New exploration on more frontier blocks, however, will likely be slowed as oil and gas prices fall and companies apply increasing caution to investing in frontier markets with nascent industries,