THE PRODUCTION COST MODELING USING EXERGOECONOMIC ANALYSIS OF DIENG GEOTHERMAL POWER PLANT

Abstract

The Dieng Geothermal Field, operated and developed by PT Geo Dipa Energi (Persero), is currently generating approximately 51,570 kW of power from two power plants: Dieng Unit-1 (60 MW) and Small-Scale (10 MW). The total exergy available in the wellhead at the current generation is 167,075 kW, with an overall power plant exergetic efficiency of around 30%. To optimize power generation, a scenario has been created to operate both power plants at full capacity. An analysis of the effect of temperature change has been conducted to better understand the energy and exergy. Additionally, thermoeconomic analysis is used to identify the cost of each equipment in order to estimate the cost at full load capacity. The power plants, located above 2000 mdpl, operate in relatively low temperature, and it is recommended to perform maintenance at the early and end of the year when the temperature is higher, as the exergy value is lower during these periods compared to the middle of the year. In order to reach full capacity, a 27-29% increase in exergy levels from the current levels is required. The highest exergy destruction occurs downstream due to the pressure drop from system pressure to atmospheric pressure. It is demonstrated that increasing the available exergy in the production well from 167.075 kW to 212.732 kW will raise the gross revenue from Rp59.708.796 to Rp81.112.832, indicating the significant impact of exergy levels on revenue. This analysis provides valuable insights for optimizing power generation and improving the revenue potential of the Dieng Geothermal Field.