Approach for Pre-Feasibility Study of Medium Enthalpy Geothermal Field, Case Study: Danau Ranau, Indonesia

Abstract

The development of geothermal fields in Indonesia is carried out under the provisions of the applicable laws and regulations, namely Geothermal Law No. 21 of 2014 and Environmental Protection and Management Law No. 32 of 2009. Based on Law No. 21 of 2014, geothermal business activities consist of preliminary surveys, exploration, and exploitation. After the exploration phase (a detailed geological, geochemical, and geophysical study), a pre-feasibility study is needed to determine the feasibility of exploration drilling. The pre-feasibility study is done to manage project risks. Danau Ranau geothermal field is one of the 166 medium enthalpy geothermal prospects in Indonesia. Activities carried out in this field were geoscience studies. This research was conducted to determine how feasible the Danau Ranau medium enthalpy geothermal field was developed for direct and indirect utilization by looking at the acceptance of technical, financial, environmental, and risk studies. The study can be a tool for the developer to decide whether to continue the next development stage. The result shows that applying the approach for Danau Ranau Geothermal Field is feasible to develop with consideration. Plant of Development by cascade model with leveling utility of energy for Danau Ranau Geothermal Field shows optimal value both in the operational and financial sides. The first level is technically designed for electricity with ORC conversion technology and the cascade level for indirect use by Lindal Diagram and community empowerment in economic and social. In financial analysis, the cascade model has optimum profitability value expressed in NPV and equity IRR.

Identification of Geodiversity and Geosite Assessment around Geohazard Area of Suoh Aspiring Geopark in West Lampung, Sumatra, Indonesia

“…This fault is relatively trending northwest-southeast. Based on historical records [23,24], the fault has been a source of significant earthquakes and calamities in Sumatra (see Figure 2). The GSF has played an important role in shaping the landscape of the study area until now.…”

“…This geothermal system's infiltration and recharge zones are Suluh Hill and Ranau Lake. In a cooling stage, magma serves as a heat source for the Ranau Lake geothermal field (Figure 5) [23,34,35]. Mount Seminung is a volcano in the Ranau Lake caldera and located around 35 km northwest of the capital district of Liwa, West Lampung, Lampung Province, Sumatra, Indonesia.…”

“…Aside from the edelweiss blossoms, geothermal manifestations can also be found at its peak. Those manifestations may be seen around Ranau Lake [23,34] and have been used by the community as tourist destination for hot springs. The geothermal manifestation around Ranau Lake is a medium enthalpy field with a reservoir temperature of 200-220 • C. The productive zone (reservoir) area range is predicted to be between 14 and 17 km 2 .…”

“…This geothermal system's infiltration and recharge zones are Suluh Hill and Ranau Lake. In a cooling stage, magma serves as a heat source for the Ranau Lake geothermal field (Figure 5) [23,34,35].…”

Resource Assessment of Ungaran Geothermal Field Using Numerical model and Monte Carlo Simulation

“…However, it has a value at that stage, but this method may be best for checking for consistency or updating the conceptual model. This method has applied in Arjuno-Welirang [3], Atadei [4][5][6][7], Patuha [8][9][10][11], Cisolok-Cisukarame [12], Kerinci [13], Tompaso [14,15], 1031 (2022) 012021 IOP Publishing doi:10.1088/1755-1315/1031/1/012021 2 Ulumbu [16][17][18], Mataloko [19,20], Karaha-Talaga Bodas [21][22][23], Songa-Wayaua [24], Danau Ranau [25,26], Lumut Balai [27].…”