RANCANGAN DAN ANALISIS KINERJA PEMBANGKIT LISTRIK TENAGA HIBRIDA GEOTERMAL-SURYA BERBASIS CLOSED-LOOP DI LAPANGAN PANAS BUMI SEMI-KONDUKTIF.

• Main Author: Maurizio Tambahani, Rivaldo
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87151
• Institution: Institut Teknologi Bandung

Today, geothermal and solar power generation technologies face power generation efficiency and operational sustainability challenges. Several regions in Indonesia are experiencing energy deficits, including East Nusa Tenggara (NTT), where the electrification rate is below 80%. Additionally, the electricity and gas sector produce over 297 million tons of CO? annually, positioning Indonesia as one of the major contributors to emissions in Southeast Asia. This research aims to develop geothermal and solar technologies to meet Indonesia’s future electricity needs while reducing the impacts of climate change. This study focuses on an integrated solution combining geothermal and solar technologies, aligning with the national energy mix targets for environmentally friendly energy. A geothermal-solar hybrid power plant (PLTH) was chosen due to the significant energy potential of the Semi-Conductive Geothermal Field in Flores, NTT, which features two-phase reservoirs and an average daily solar radiation intensity of 5.6 kWh/m². This study presents a design and evaluates the performance of a closed-loop PLTH using single flash technology. Validation was conducted by comparing simulation results with empirical field data, such as pressure and temperature, to ensure the reliability of the model. System performance analysis was conducted using a thermodynamic model to achieve the study’s objectives. The model was simulated with MATLAB and Aspen HYSYS software, which are capable of accurately simulating complex energy systems. Two key configurations were tested: (1) a closed-loop PLTH system without solar panel augmentation, focusing on the system's baseline efficiency, and (2) a system with heat exchange powered by thermal solar panels, designed to increase the working fluid's temperature before entering the turbine, thereby significantly improving thermal efficiency. The closed-loop system addresses challenges related to reservoir fluids that cannot naturally rise to the surface. Furthermore, this system reduces scaling risks in the fluid flow, both in wells and surface components, and supports long-term energy sustainability through a closed-loop cycle without direct contact between the working fluid and the reservoir. The results of this study show that the combination of geothermal and solar technologies increases power generation efficiency by up to 15%. In this configuration, thermal solar panels transfer heat to the working fluid before it enters the turbine, enhancing the effectiveness of the energy conversion process. This approach demonstrates that integrating solar and geothermal energy can complement the weaknesses of each energy source. The findings also highlight the contribution of PLTH to increasing electrification rates and reducing dependence on fossil fuels, minimizing environmental risks from conventional power generation technologies, and offering an adaptive power generation model to meet future energy demands both at the local level and the global level. The development of renewable energy-based power generation systems supports Indonesia’s transition to clean energy and contributes to climate change mitigation by reducing carbon emissions by up to 50% compared to standalone geothermal power plants (PLTP). The findings of this research are relevant for supporting the National Energy Plan (RUEN) 2025 and form the foundation for implementing renewable energy policies, including increasing the share of geothermal and solar energy in the national energy mix to 23% by 2025. With the urgent need for electrification in NTT, this contribution holds significant potential for improving local access to electricity. This integrated green energy system has promising prospects as a model for clean and sustainable energy applications, meeting future electricity needs not only for Indonesia’s geographical and meteorological conditions but also as a reference for hybrid power plant development globally, especially in tropical regions with similar renewable energy potential.