PLN renewable energy chief Muhammad Sofyan said that the Lahendong Unit 4 and Ulumbu plants would start commercial operation in February after completing testing that began in December.
“The two geothermal energy plants are currently conducting reliability tests for a month so that in February, the plants can begin commercial operation,” Sofyan said on Friday. The Ulumbu plant has a capacity of 2×2.5 MW. The geothermal potential at the site is estimated at 10 MW.
Lahendong Unit 4 has a capacity of 20 MW. The fourth unit will complement three currently operating units in the area, bringing total production at the site to 80 MW. Geothermal development in Lahendong is run by Pertamina Geothermal Energy (PGE). The cost of electricity from the plant has been pegged at 4 US cents per kilowatt-hour (kWh).
PGE has committed to open two more 20-MW units in Lahendong by 2013. Exploration for a geothermal energy supply for the planned units was underway since 2008, before officials settled on an area in South Lahendong with an estimated potential of 220 MW.
When construction of the Unit 5 and 6 plant has been complete in 2014, PGE will start construction on Unit 7 and 8. The geothermal energy supply for the plants is expected to come from Kotamobagu, which has a potential of 180 MW. In Lampung, the Ulubelu Unit 3 and 4 plant was expected to yield 110 MW, bringing the site’s total production to 220MW, Sofyan said.
“Unit 3 and 4 is expected to become operational in July or October,” he added. The price of electricity from the plant has been pegged at 4 cents per kWh.
Despite holding 40 percent of the world’s geothermal reserves of around 28,543 megawatts, Indonesia’s geothermal energy development has been minimal.
Although Indonesia began developing geothermal power 30 years ago, the nation currently produces 1,341 MW of geothermal power a year, about 4.6 percent of its potential. PLN’s use of renewable energy has been low as of the third quarter of 2011.
Coal dominated the company’s energy mix at 42.2 percent, followed by oil-based fuels at 23.7 percent, natural gas at 22 percent, hydro at 6.7 percent and renewable energy (including geothermal) at 5.4 percent. PLN previously said it wanted to boost geothermal energy use to 7 percent.
Indonesia is an archipelago of more than 17,000 islands, and many volcanoes stretch across major islands such as Sumatra and Java along a range that makes it desirable to tap these geothermal energy sources for the production of electricity.
Indonesia, a nation of 240 million people, had power-generation capacity at as much as 28,462 MW as of the end of last year, according to PLN data.
Coal-powered plants account for around 42.2 percent of that capacity, with diesel-fired plants 23.7 percent, gas 22 percent, hydropower plants 6.7 percent and geothermal energy and other renewable energy at 5.4 percent.