Geothermal energy use is increasing around the world including in Indonesia. By year 2020, Indonesia is predicted to rank second among world’s largest users.
Electrical production is a major indicator for the success of the construction and operation of a geothermal power plant. To maximise electrical production, the reliability performance of geothermal plant is influential, also to achieve profitability target of the geothermal plant.
“For investors, the level of electrical production is one major indicator for their investment successes, and become a thing to consider for reinvesting or not. The high reliability of geothermal plant will produce interesting benefits for investors, which is one important aspect in accelerating the role of geothermal plants,” said Rachmawan Budiarto, S.T., M.T. during his doctoral promotion at Faculty of Engineering UGM on Monday (25/7).
The formulation of geothermal plant reliability levels is useful for considering initial investment, additional investment, designing, and development of plant maintenance. Even so, there have been no studies being made that formulates the reliability criteria that can specifically show the reliability level of a geothermal by taking into account the unique variables of geothermal plants.
That is why the lecturer in Nuclear and Engineering Physics focused his dissertation on the aspects of reliability of geothermal plants, especially with high enthalpy that is common in the world. For identification steps, he analysed the reliability in cases of high enthalpy in Indonesia, the Philippines, and New Zealand.
“My analysis gives an answer to the four basic questions: problem risks that can happen at geothermal plants, problems at surface components of plants, cause and impacts,” he explained.
The plant reliability in his opinion can be expressed in continuity and stability of steam supply that is used to get the continuity and stability of electrical production. He developed a composite indicator to state the reliability level of a geothermal plant that consists of eight single indicators, among them are electrical production, steam supply, internal scaling problem, internal corrosion and other internal problems.
The reliability analysis he undertook produced a new finding showing that scaling or surface movement of various components become the strongest variable that causes problems at the observed geothermal plants. The observed plants - Wayang Windu dan Lahendong – are categorised as “reliable” while three others, Kamojang, Derajat, and Awibengkok, are “close to reliable”. The Dieng geothermal plant has the low category of “close to unreliable”.