THE ENERGY ALTERNATIVE POTENTIALS IN CIANJUR-SUKABUMI AND KUNINGAN AREA, WEST JAVA, INDONESIA

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1 THE ENERGY ALTERNATIVE POTENTIALS IN CIANJUR-SUKABUMI AND KUNINGAN AREA, WEST JAVA, INDONESIA Emi Sukiyah, Ildrem Syafri, Nana Sulaksana and Adjat Sudradjat Faculty of Geology, Padjadjaran University ABSTRACT The energy generation in West Java is based mainly on the combustion of hydrocarbon. Some important dams were already built, however due to the spatial problem competing with the population, the construction of new dams are not feasible. Therefore the small scale damless hydroelectric generations might contribute to the energy needs and reduce the dependancy on the energy generated from hydrocarbon. The geomorphologic condition of West Java is favourable for small scale hydropower generation. Medial axis uplifting of the island has provided the differential elevations producing the heads for the power generations. The geomorphologic cataracs resulted from the altenation of pyroclastics and lava flows enhance the development of the heads. Cianjur and Kuningan areas representing south and north of West Java, were taken as samples to investigate the small scale hydropower potentials. The result shows that as many as 42 locations with the total heads of 1,792 meters were inventorized. The total differential elevations of the heads might yield approximately 19,340 Watts. The area covered by the potentials was estimated to be 8,700 km 2 with more than 20 rural growth centers. Keywords: small scale damless alternative energy, geomorphologic condition, south and north West Java, rural growth centers. INTRODUCTION West Java is located in western portion of Java Island. It surrounds Jakarta, the capital city of Indonesia which is also the center of economic activities. The industrial zones flock in the vicinity of Jakarta due to the comfortable infrastructure. Energy is the most important element to run the manufacture which is easily available in the area. On the other hand the industry has drawn the labours from entirely parts of the country, particularly from Java island to settle down in the western part of Java. The population of 1

2 West Java therefore, exceeds almost 50 millions, the highest number in Indonesia. Consequently, the needs for domestic energy increases exponentially. To date the source of energy remains from the combustion of fossils, both hydrocarbon and coal. The hydropower built more than half a century ago in Jatiluhur area, Purwakarta contributes a small portion in the energy generation. Similarly with the two others, namely Saguling and Cirata located at the upstream of Jatiluhur dam which produce an insignificant contributon to the electricity needs. West Java as a matter of fact endows a potential amount of hydropower energy. The geomorphologic condition provides the heads along the south and northern part of West Java. The dense population however, hampers the construction of dam because it consumes significant amount of land area rarely available. The damless hydroelectric power therefore, might provide the alternative to supply the domestic energy needs and thus, might reduce the dependency on the hydrocarbon. Two pilot areas were chosen to look into the possibility to exploit the alternative damless hydropower energy. Kuningan and Cianjur-Sukabumi area respectively represent the north and south slopes of West Java (Figure 1). METHODOLOGY To calculate the damless energy potentials, we apply the following formula recently developed by Ministry of Energy & Mineral Resources (2007): Pt = 9.81 x Q x H x nt... (1) Ptrans = 9.81 x Q x H x nt x nbelt... (2) P = 9.81 x Q x H x nt x nbelt x ngen... (3) where, P t = Turbine axis power P trans = Transmitted power to the generator P = Power generated by the generator Q = Water debit (m 3 /second) H = Effective height (m) n t = Turbine effisiency; 0,74 for crossflow turbine T-14; 0,75 for local propeller open flume turbine; n belt = 0,98 for flat belt ; 0,95 for V belt n gen = Generator efficiency 2

3 Based on the calculation method mentioned above, the field observation focused on the inventarization of river basin, watershed and mostly the morphologic features to measure the heads for the hydropower generation. Those of the fundamental elements readily appear on the satellite images of thematic mapper available at the Geological Agency of Indonesia. The digital and advent processing provides detailed information on the characteristics of the morphologic configuration. The imagery might provide also the neotectonic phenomena among others shown by the terraces along the southern coast and river courses. The phenomena identify the formation of the geomorphologic heads. The Geo-Positioning System (GPS) loctaes the accurate position of the heads. The topographic maps of southern part of Java, namely Sukabumi, Cianjur, Garut and Tasikmalaya serve as base maps. The geologic maps of those quadrangles prepared by Sukamto (1975), Koesmono et al. (1996), Alzwar et al. (1992), Budhitrisna (1986) and Supriyatna et al. (1992) provide the comprehensive geological information. Similarly in Kuningan area of the Northern part of West Java, the geologic maps of Arjawinangun, Majenang and Cirebon quadrangles respectively prepared by Djuri (1995), Kastowo & Suwarna (1996) and Silitonga et al. (1996) readily share the comprehenssive geological information. Laboratory works carry out quantitative geomorphologic analysis and petrographic determination. RESULTS AND DISCUSSION The South-North plate movement of Indian Ocean produces an uplifting of West Java. The uprising resulted in the formation of a mountain range in the medial line of the area. Further, the weak zones developed in the crest of the mountain, permitting magma to extrude to the earth s surface producing volcanoes. The volcanic summits crown up the mountain range and provide a row of geomorphologic high to tap water from the humid air. Additionally, the dust and gases emmited from the volcanic centers convert the clouds into the water droplet. Intensive rain falls thus, take place in the medial line of West Java. The area located in this line keeps a large amount of water reserve. Partly, and getting worst presently, rain water becomes the runoff, due to the deforestation. The south and northern slopes of West Java, flank the median line resulting in the differential height ideal for the hydropower generation. The crest of the mountain attains 3

4 the height ranges between 900 to 1200 meters, while the extend of the slope to the North is about 60 kilometers. In the Southern part, the slope extends about 30 kilometers which produces more and higher heads. The alternations of volcanic products consisting of massive lava flows, breccia and loose volcanic sands enhances the formation of the heads. Similarly the alternating clastic sediments between clay and sandstone create favourable geomorphologic condition for the formation of the heads. (Figure 2). In the Northern part of Java, represented by Kuningan area, the digital satellite image analysis shows a moderately deformed area (Figure 3). The lithology consists of the alternation between hard and soft clastic sedimentary rocks. Intensive deformation occurs in the southern part of Kuningan area and diminishes to the north. The SE-NW structural trends dominate the area. Lithologically the Tertiary Halang and Pemali Formations underlain by Quaternary volcanic products cover the area. The investigation resulted in the identification of 15 potetial locations in west, south and east Kuningan area. The calculation of the microhydro potentials shows that the heads in Kiaradomba and Cikadu might produce more than 1,000 watt of electricity. Other locations among others Hantara, Ciniru, Ciangir, Ciwaru and Karangkancana respectively produce less than 100 watts. In the South, where the slope extends less than in the North, it produces rough morphology and higher heads (Sukamto, 1975). The rocks chiefly consists of volcanoclastics and intrusives (Koesmono et al., 1996). In South of Garut the lithology composes of Tertiary and Quaternary volcanic rocks (Alzwar et al., 1992). Geologically the stratigraphy builds up the rock sequence of Jampang Formation which underlain by Bentang Formation (Budhitrisna, 1986, Supriatna et al., 1992). The Tertiary sediments both in the South and northern slopes create the cataracs consisting of series of heads. The water potentials of southern part of West Java covers 20 river basins, among others Cibuni (1,428 km 2 ) and Ciwulan (1,166 km 2 ) being the two largest and Cibabalukan (89.11 km 2 ) the smallest. The river courses mostly forms dendritic pattern which partly combined with rectangular and trellis. An elongated water basin might provide most favourable condition for the formation of the heads. The area of Cianjur- Sukabumi endows abundant potentials for mini-micro hydropower (Figure 4). In 4

5 Cipandak river basins of Cianjur, some seven locations with the total heads of 942 meters exist which might generate approximately 11,500 watts of electricity. In Sukabumi area the observation shows that the potentials exceed 2,000 watts of electricity. Both in South and Northern parts of West Java the energy potentials yield the following figures (Table 1): Table 1. Total energy alternatives in the rural area of South and Northern parts of West Java Area Number Areal extent Total heads Potentials (km 2 ) (m) (Watts) Cianjur-Sukabumi 27 8, ,840 Kuningan ,500 CONCLUSION AND RECOMMENDATIONS The above findings and discussion conclude that the geomorphologic features existing in the North and South slopes of the median line of West Java provides the favourable condition for the formation of heads which might produce energy potentials. The result shows that as many as 42 locations with more than 1,792 meters of total heads were inventorized. The energy potentials might yield approximately 19,340 Watts of electricity covering the area of 8,700 square kilometers with more than twenty rural growth centers. The generation of mini-micro or even nano electric power can serve as the energy alternative to reduce the dependency on hydrocarbon. Further more, the dense population in West Java hampers the construction of water dams for the generation of hydropower. In contrary, the damless electric generation might offer an alternative. The energy potentials distributes evenly in the investigated area. Similarly with the development centers located in the area, which minimize the construction of electric distribution grids. The development of mini-micro and nano hydro power would accelerate the rural electrification program launched by the government. It is therefore strongly recommended to extend more attention to the alternative energy endowed in the rural area of North and Southern parts of West Java. 5

6 REFERENCES Afandi, Tjetje, Rajiyowiryono, Hardoyo, Adisaputro, Karsono, & Wongsosentono, Soeharto Environmental geology in rural development of southern part of West Java. Proceeding of the Geological Student Association Seminar, Bandung. Alzwar, M., Akbar, N. & Bachri, S Geologic map of Garut and Pameungpeuk Quadrangle, Jawa. Scale 1: Geological Research and Development Center, Bandung. Budhitrisna, T Geologic map of Tasikmalaya Quadrangle. Scale 1: Geological Reseach and Development Center, Bandung. Ministry of Energy and Mineral Resources Micro-hydro. Clearinghouse Renewable Energy and Conservation. Djuri Geologic map of Arjawinangun Quadrangle. Scale 1: Geological Researach and Development Center. Bandung. Kastowo & Suwarna, N Geologic map of Majenang Quadrangle. Scale 1: Geological Research and Development Center. Bandung. Koesmono, K, Kusnama, & Suwarna, N Geologic map of Sindangbarang and Bandarwaru Quadrangle. Scale 1: Geological Research and Development Center. Bandung. Silitonga, P.H., Masria, M. & Suwarna, N Geologic map of Cirebon Quadrangle. Scale 1: Geological Research and development Center. Bandung. Sukamto Geologic map of Jampang & Balekambang Quadranle. Scale 1: , geological research and Development Center. Bandung. Supriatna, S, Sarmili, L, Sudana, D, & Koswara, A Geologic map of Karangnunggal Quadrangle. Scale 1: Geological research and Development Center. Bandung. 6

7 Figure 1. Index map of the investigated area located in South and Northern part of West Java represented respectively by Cianjur and Kuningan area. Figure 2. The alternating sandstone and clay provide the ideal location for the formation of head. Photograph shows the waterfall of 15 m head in SE of Ciangir in Kuningan area estimated to produce approximately 500 Watts of electricity (Photo by Sukiyah). 7

8 Figure 3. Satellite imagery in Kuningan are depicts the configuration of the deformed alternating sedimentary rocks favorable for the formation of the heads. The drainage demonstrates the influence of neotectonic in the area. The quadrangle represents approximately 1600 km 2. (Source: Geological Agency of Indonesia) Figure 4. The energy potentials in Sukabumi-Cianjur area, Southern part of West Java for the generation of mini-micro or nano hydropower. The rows of stars represent the magnitude of the potentials energy respectively from big to small > 1500 Watts, Watts, Watts and <500 Watts. 8

9 Theme : energy ID : 140 Title : THE ENERGY ALTERNATIVE POTENTIALS IN CIANJUR AND KUNINGAN AREA, WEST JAVA, INDONESIA emi_s@unpad.ac.id & ifaamelia@yahoo.com ildrem_s@unpad.ac.id nana_s@unpad.ac.id asudradjat@unpad.ac.id & asudradjat@yahoo.com 9