PLN to build geothermal power plants in North Sulawesi
Yongker Rumthe, The Jakarta Post, Manado
State-owned electricity company PT PLN is developing power plants using geothermal energy in North Sulawesi to replace the hydropower ones which are expected to cease functioning within ten years due to the rapid disappearance of Lake Tondano.
Harry Lumentut, spokesman for PLN's Region VII overseeing North Sulawesi, Central Sulawesi and Gorontalo, told The Jakarta Post recently that the planning was based on the fact that North Sulawesi had abundant geothermal energy reserves that could be utilized for decades and the state-owned oil company PT Pertamina had successfully developed two geothermal projects in Lahendong, Tomohon and Minahasa.
He said that according to recent research conducted by PLN- hired experts, the province's volcanic territory had an abundance of geothermal resources that could be used to drive the power plants for a long time.
"Based on the researchers' recommendations, PLN is developing geothermal power plants in Tompaso, Minhasa and in Bukit Ambang, Mobago Regency. The two plants will be able to produce 555 megawatts which is enough to meet the total power demand in Sulawesi," he said.
He added that PLN was still negotiating with Pertamina on the operation of the Lahendong geothermal plants because according to the law, PLN has a monopoly on the supply of power to consumers.
Pertamina has also developed a mega project of geothermal plants in Sarulla, Central Tapanuli, North Sumatra.
Harry explained the investment for geothermal projects was relatively more expensive than diesel-powered plants but cheaper than hydro powered-plants.
He said they would need to invest US$800 per kiloWatt for a diesel-power plant while a geothermal plant needed $1,300 per kiloWatt and a hydropower plant needed $1,500 per kiloWatt.
Harry however said geothermal plants had other benefits because geothermal resources were renewable and environmentally friendly, the operating costs were slight lower than hydropower and that geothermal energy could be utilized for medical and agricultural purposes.
"We saw some of the geothermal energy's uses when we conducted a comparative study in Thailand and other Asian countries recently," he cited.
He said he was optimistic that it would lead to lower electricity rates in Sulawesi.
He said local people would be included as shareholders in the projects to win their support.
Harry acknowledged that the two hydropower plants would be closed down because in the next ten years, Lake Tondano would no longer be able to supply water to the two power plants.
"According to a recent study conducted by the Japan International Cooperation Agency (JICA), the lake's water level has dropped to a depth of only 17 meters from 40 meters in 1934 due the shrinking catchment areas around the lake and the sedimentation from 35 tributaries flowing into the lake," he said, while adding that millions of tons of silt per year was piling up in river.
Abnormal oversiltation is usually caused by deforestation upstream because of massive disturbance of jungle topsoil.
Due to the technical and environmental problems, PLN's operational costs have increased by 50 percent over the last several years.