Sustainable Development Model of Geothermal Energy (A Case Study at Darajat Geothermal Power Plant, Garut-Indonesia)

World consumption of energy from fossil fuels has continued to increase with the increasing world population growth.  In Indonesia, the average growth of energy consumption is 8.5% per year due to economic and population growth. The majority of national energy demand is fulfilled by fossil fuels, but their reserves are decreasing. These situations have forced the government of Indonesia (GOI) to perform efficiency use of fossil fuels and find new alternative energies which are relatively cheaper and environmentally friendly. One of the new alternative energies that meets this criteria is geothermal, which is considered as a renewable energy, has ample reserve, and low CO2 emission. GOI has established the 2006-2025 geothermal development roadmap targeting 9,500 MW in 2025 or a contribution of 5% to national energy consumption. However, current use of geothermal in 2012 is only 1,226 MW or 4% of Indonesia’s geothermal potential (29,215 MW), therefore, this is considered a challenging target for Indonesia to achieve (Sukarna, 2012).This paper describes a conceptual model to develop sustainable geothermal energy to help achieve the GOI challenging target, based on a case study at a Geothermal Power Plant (GPP) in Darajat near Garut, Indonesia. It is intended to provide support for decision makers to accelerate sustainable development of geothermal energy based on social, environmental, and economic aspects. Therefore, some analyses are required to be performed and synthesized so that an optimal, comprehensive and an integrated model of sustainable geothermal development can be obtained. Various analysis conducted are based on a system approach, both hard and soft system approaches. The hard system approach is an analysis of economic investment feasibility of geothermal development at GPP Darajat Garut by calculating Net Present Value (NPV) and Internal Rate of Return (IRR). The soft system approach is a compilation result of the sustainable analysis of MDS (Multi-Dimensional Scaling), legal/regulation review, AHP (Analytical Hierarchy Process), and ISM (Interpretative Structural Modeling). These analysis results become inputs in designing a conceptual model of sustainable geothermal energy development. The financial analysis result indicates that investment for geothermal energy development is economically feasible with positive NPV and IRR. The MDS analysis result shows that geothermal energy development at GPP Darajat is relatively sustained. A regulation review indicates that there are government regulation inconsistencies and overlaps, and that permitting requirements need to be improved. The AHP analysis result indicates that the government policy consistency is the most important factor that influences improvement to other factors.  The ISM analysis result indicates that 3 (three) elements have to be considered for sustainable geothermal development: 1) central government as an actor is the strongest driving power and influence for others, 2) government policy consistency is considered as a main obstacle, and (3) developing a long term strategy and policy are the key elements and main drivers that influence others. Based on those analyses results a conceptual model of sustainable geothermal energy development has been developed which consists of a management system, funding/budget support, actor to manage, and regulation management. Keywords: Conceptual model, geothermal energy development, Darajat Garut, MDS, AHP, ISM.

STABILISASI TANAH GAMBUT RAWA PENING DENGAN SEMEN DAN GYPSUM SINTESIS (CaSO4.2H20)

ABSTRAKSI Tanah gambut dikategorikan ke dalam tanah lunak yang sulit diatasi terutama bila dijadikan tanah dasar suatu trase jalan. Untuk itu perlu dilakukan studi untuk meningkatkan kemampuan tanah gambut yaitu dengan cara stabilisasi tanah. Salah satu cara stabilisasi tanah adalah dengan menambah bahan tambah stabilisasi untuk tanah organik. Dalam penelitian ini digunakan bahan tambah 5% semen portland dengan gypsum bervariasi yaitu 5%, 10%, dan 15% dari berat kering tanah. Agar terjadi reaksi antara tanah gambut dengan PC dan gypsum maka dilakukan masa perawatan sampel yaitu 0 hari, 14 hari , dan 28 hari. Pelaksanaan penelitian dibagi menjadi 2 bagian yaitu penelitian pendahuluan dan penelitian pokok. Penelitian pendahuluan digunakan untuk mengetahui sifat indeks, sifat fisik, dan sistem klasifikasi tanah. Sedangkan penelitian pokok yang dilakukan adalah uji CBR rendaman yang diikuti uji pengembangan terlebih dahulu. Hasil penelitian laboratorium yang dilakukan menunjukkan bahwa tanah gambut Rawa Pening termasulc fibrouse peat. Kadar abu 37,73%, kadar serat 62,12%, dan kadar organik 62,27%. Batas cair turun dimana pada tanah gambut 104,37% menjadi 92,9% pada 5% PC dengan 15% gypsum pada masa perawatan 28 hari. Batas plastis pada tanah gambut 116,78% menjadi 92,64% dan indeks plastis dari 0% menjadi 0,26%. Terhadap hasil uji Proctor standar campuran 5% PC dengan gypsum menyebabkan berat kering maksimal naik yaitu dari 0,475 menjadi 0,579 dan pada kadar air optimum mengalami penurunan dari 106,25% menjadi 52,5%. Pada pengujian pengembangan secara keseluruhan mengalami penurunan dari 2,049% menjadi 0,017%. Alcan tetapi pada campuran 5% PC dengan 15% gypsum nilai pengembangan mengalami kenaikan jika dibandingkan dengan campuran lainnya Hasil paling optimum adalah stabilisasi tanah gambut dengan campuran 5% PC dan 10% gypsum untuk masa perawatan 28 hari yaitu 8,17%. Nilai CBR secara keseluruhan naik dari 2,78% menjadi 8,17%, akan tetapi pada campuran 5% PC dengan 15% gypsum terjadi penurunan nilai CBR menjadi 5,80%. Secara keseluruhan nilai CBR dari stabilisasi tanah gambut dengan PC dan gypsum memenuhi persyaratan Bina Marga sebagai tanah dasar, karena nilai CBR yang didapat lebih besar dari 5%. Jadi bahan semen dan gypsum dapat dijadikan bahan stabilisasi altematif untuk tanah gambut sebagai tanah dasar. Kata kunci : Gambut, Tanah Dasar, Stabilisasi, Penelitian Pendahuluan, Penelitian Pokok ABSTRACT Peat soil is categorized into soft soil that difficult to overcome especially if it used to be sub grade of road trace. So it needs study to increase peat soil ability that is soil stabilization. One of the soil stabilization is by adding stabilization agents for organic soil. In this research stabilization agents that used are 5% Portland cement with gypsum in varying percentage: 5%, 10%, and 15% of soil density. Sample curing time during 0 day, 14 days, and 28 days must be done in order to create reaction between peat soil with Portland cement and gypsum. This research is divided into 2 parts, which are: Preliminary research and Prime research. Preliminary research was done to find out index behave, physic behave, and soil classification system. Prime research was done by CBR soak test that followed by swelling test before. The result from laboratorium research shows that peat soil from Rawa Pening is fibrous peat category, with 37,73% ash content, 62,12% fiber content, and 62,27% organic matter. The liquid limit decreased from 104,37% to 92,9% at 5% PC with 15% gypsum during 28 days curing time. The plastic limit decreased from 116,78% to 92,64%, plasticity index decreased from 0% to 0,26%. Towards result of Standard Proctor test, mix of 5% PC with gypsum caused maximum density increased from 0,475 to 0,579, at water content optimum it decreased from 106,25% to 52,5%. From development test for overall decreased from 2,049% to 0,017%, but at mix of 5% PC with 15% gypsum they decreased if they compared with others mix. The optimum result from peat soil stabilization that is mix of 5% PC with 10% gypsum in during 28 days curing time, with result 8,17%. CBR values for overall are increased from 2,78% to 8,17%, but at mix of 5% PC with 15% gypsum there was CBR value decreased to 5,80%. CBR values for overall from peat stabilization mix with Portland cement and gypsum fill rules from Bina Marga like sub grade, because the CBR values greater than 5%. So Portland cement and gypsum matter can be used to alternative stabilization agents for peat like sub garde. Keywords: Peat soil, Subgrade, Stabilization, Preliminary Research, Prime Researc

Development Strategies Analysis Using the SCOR Method Approach: A Case Study from Medical Device Company

Objective: This study aims to measure the performance of supply chain management at PT. Multi Anugrah Satu identifies supply chain management activities that require improvement and provides recommendations for improving performance strategies in supply chain management activities Design/Methods/Approach: The initial stage of this study is to determine KPI and scores for the weighting of the COR and AHP methods, which respondents fill in, then the data are processed and identified using OMAX and the Light System in measuring the improvement of SCM performance management at PT. Anugrah Satu. Findings: Using the SCOR method the firm obtains 83.48 out of 100. The value suggests a need for strategy that focuses more on decision-making at the management level and in the long term. Originality: This study develops strategic operation management science and help improve public health levels during the COVID-19 pandemic. Practical/Policy implication (optional): The implications of supply chain management strategies for management and business practices are developing advanced logistics management as a strategy to increase competitive advantage for the company