1 Electricity Planning in Indonesia using DECADES Tools 1 Agus Sugiyono La Ode M.A. Wahid Irawan Rahardjo Agency for the Assessment and Application of Technology (BPPT) Farid S. Kresna National Atomic Energy Agency (BATAN) 1. Introduction BPPT, Indonesia and IAEA, Austria have been conducting a cooperation study on electricity optimization planning for Indonesia. In the phase I study (1995-1997) that carried out within the Research Contract with titled Comparative Assessment of Electricity Supply Strategies in Indonesia, BPPT is still using MARKAL model. In the phase II study (1997- 1998), a software package (DECADES) developed by IAEA is used for the study. The title of the study is Case Studies on Comparing Sustainable Energy Mixes for Electricity Generation in Indonesia. The objective of the phase II study is to design sustainable energy mix for electricity generation in Indonesia for a long period (1995 - 2020) as an optimum result of the integration between national economic growth, common energy technology, and environmental aspects. Scopes of the study are: - to improve current database in CSDB - to build strategic scenarios that can maintain sustainable energy mix for electricity generation. - to optimize the electricity supply by using DECPAC Model. - to analyze the result and the environmental impact. 2. Background on Indonesia In DECADES Tools one of the main input data is electricity demand projection. Some background on geographical, social and economic condition in Indonesia need to consider before make a projection. Indonesia is the largest archipelago in the world. It consists of five major islands and about 30 smaller groups. The geography of Indonesia is quite magnificent, supported by tropical climate and weather. The climate changes every six months. The dry season (June to September) is influenced by the Australian continental air masses; while the rainy season (December to March) is the result of the Asian and Pacific Ocean air masses. The air contains vapor, which precipitates and produces rain in the country. Tropical areas have rains almost the whole year through. Indonesia is the world's fourth most populated country with a population of 200 millions. The population growth is controlled through efforts to lower the birth and mortality rate, especially that of infants and children. These efforts in particular have been implemented through family planning programs which also have the purpose of improving the welfare of mother and child and at the same time create a small, happy, and prosperous family. Family planning program in Indonesia is success, in which it is able to reduce the population growth rate from 2.10 % per year in 1967-1970 to 1.66 % per year in 1990-1995. Based on BAPPENAS estimation, the average population growth rate during 1995-1999 period is 1.6 % 1 Presented at IAEA Regional Training Course on Comparative Assessment of Nuclear Power & Other Energy Sources in Support of Sustainable Energy Developments, 8 June – 3 July 1998, Taejon, Korea