Exploring the feasibility of inter-island transmission interconnection in Indonesia

Abstract

Indonesia started its journey towards a net-zero energy system. Research and developments towards these targets are currently well underway. However, present-day prediction models show that the rising demand of the island will not be met with the renewable energy technology potential. One solution for this problem is the development of power interconnections between the power systems of the Archipelago. However, short-term planning and speculations about the feasibility of inter-island interconnections block their construction. This study aims to explore the feasible options for inter-island interconnections and recommends the next steps that can be researched. The method to answer this research question is through the combination of a techno-economical model and an institutional analysis. The techno-economical model utilizes the energy planning model ’Calliope’, as the foundation of this model was already developed by researchers at TU Delft. To include geographical features, a GIS (Geographic Information System analysis) is performed and its outcomes are used to analyse the results coming from the Calliope model. The results from this techno-economical analysis are then used as input for the institutional analysis. The latter is built upon the existing Williamson framework. Due to the limited scope and timeline of this study, the aspects planning of transmission infrastructure, financing of transmission infrastructure and contractual arrangements between public and private parties are chosen as focus points in the institutional analysis. The state-of-the-art technology used for inter-island interconnections, or submarine power cables in general, are High-Voltage Direct Current (HVDC) cables. The advantage of HVDC over HVAC (High-Voltage Alternating Current) cables is their ability to transmit power over longer distances while creating less envi- ronmental impact due to limited electromagnetic interference. The planning of submarine power cables is a relatively new subject in academic literature. The impor- tant geographical features to consider in the design process of submarine power cable routing found in this study are the depth of water (bathymetry), seabed slope, seismic regions, and protected zones. These ge- ographical features can be categorized in terms of their impact on the cost and risk of breakage of the cables. This study found through a techno-economical analysis that there are multiple inter-island intercon- nections that are found to be needed in a Calliope power model of Indonesia and feasible considering the aforementioned geographical features. The visual shortest-path routing of these feasible cables has been determined through an AHP (Analytic Hierarchy Process), analysis combined with a Dijkstra shortest-path algorithm. On the institutional side of the result, this study found that there are multiple barriers that could form a barrier to the development of inter-island interconnections. The main issues found have to do with the planning, financing and contraction of the institutional side of transmission infrastructure development. In order to soothe these barriers the following recommendations are constructed; using an integrated transmission capacity planning approach, institutional strengthening for investment and creating a governance body dedicated to interconnectivity. The conclusion of this study is that there are feasible interconnections for accommodating renewable energy technology integration in Indonesia. The found feasible routes of this methodology consist of Bali- Nusa Tenggara Barat, Kalimantan Barat-Daerah Khusus, Jakarta-Kalimantan Tengah, Jawa Tengah-Kalimantan Selatan, Jawa Timur-Kalimantan Tengah, Jawa Barat-Lampung Banten, and Kepulauan Riau-Riau and between Kalimantan Barat and Jawa Barat. Institutional adjustments are found to be crucial for fostering this interconnected system. Institutional recommendations involve integrating interconnections into the RUPTL (Electricity Supply Business Plan), strengthening foreign investment with clear policies, and ensuring transparent contractual arrangements between public and private entities. Moreover, prioritizing grid balancing and exploring sustainable financing methods like green bonds further support these efforts. The most important limitations of this study are the minimal use of scenarios, the use of only one energy system modelling software (Calliope) and the limited scoping for the institutional analysis. As for future research, this study invites researchers to think about the specific power flow of the system, the operational challenges, social engagement and public perception and comparison to other archipelago countries