In recent years, the goal of lowering emissions to minimize the harmful impacts of climate change has emerged as a consensus objective among members of the international community through the increase in renewable energy sources (RES), as a step toward net-zero emissions. The drawbacks of these energy sources are unpredictability and dependence on nature, leading to unstable load power supply risk. One way to overcome instability in the power supply is by using a battery energy storage system (BESS). Therefore, this study provides a detailed and critical review of sizing and siting optimization of BESS, their application challenges, and a new perspective on the consequence of degradation from the ambient temperature. It also reviews advanced battery optimization planning that considers battery degradation, technologies, degradation, objective function, and design constraints. Furthermore, it examines the challenges encountered in developing the BESS optimization model and evaluates the scope of the proposed future direction to improve the optimized BESS, especially its battery.

Distributed Generation (DG) installation in the distribution system aimed to reduce power losses, increase the voltage profile, and increase the amount of power supplied. One DG that can be implemented is based on photovoltaic (PV). The stochastic PV characteristics will cause ups and downs of the power produced. When the power generated is greater than the load downstream, it will potentially cause the power flow to be two-way. The method for determining the placement location and optimal DG capacity is needed so that the effect of PV penetration on changes in power flow and voltage profile is still within the permissible limits.This study proposed the FPA algorithm to determine the optimal location and DG capacity to reduce power losses in the distribution system with a case study of distribution network in Semanu Substation, Gunung Kidul Yogyakarta. The findings confirmed that the FPA method can be used to determine the placement location and optimal DG capacity of 9.501 MW, with active power losses after DG having decreased by 68.75%, and reactive power losses of 61.40%.

Energy sustainability has become one of the main issues in power system planning in the Indonesian archipelago system, which has many small, isolated systems. For that purpose, green and sustainable generation expansion planning (GEP) procedures based on local energy resources is required. GEP is a necessary procedure for fulfilling electricity demand, which determines the generating units to be installed within a specified time horizon with minimal total costs as the objective function. This study uses GEP considering the interconnection option among the existing small scattered generation systems in Maluku: the isolated Ambon, Seram, Haruku, and Saparua systems. With interconnection, the utilization of local renewable energy sources would be increased, especially biomass, which has abundant potential in these areas. The GEP was simulated in the PLEXOS environment using mixed-integer linear programming (MILP). For comparison purposes, there were interconnection and isolated system scenarios. The results showed that the interconnection system would have a high share of a renewable energy source (RES) of up to 54% in 2050, most of which is biomass as the primary local energy source. The interconnection system scenario met the LOLP criteria and had a lower reserve margin and total costs than the isolated scenario, with USD 773.7 million.

HVDC has experienced substantial growth in utilization globally, attributable to its superior capacity for transmitting large amounts of power relative to its HVAC counterpart and its increasingly competitive pricing. Voltage source converter technology, a variant of HVDC, is particularly well suited for transferring bulk offshore power, whether in point-to-point or multiterminal configurations. Most existing HVDC connections function as interconnections between strong AC grids or between strong and weak/islanded AC grids. However, with the expanding use of distant offshore generation, the establishment of energy islands, and the electrical interconnection of archipelagic nations such as Indonesia, the potential arises for HVDC to link two weak AC grids or even a weak and very weak AC grid. This paper provides a comprehensive review of various HVDC technologies appropriate for such connections, focusing on converters, cables, and circuit breakers. It also offers a technological and methodological assessment of HVDC reinforcement for interconnecting weak AC grids. Furthermore, the paper examines HVDC applications concerning control strategies optimized for weak grid interconnections. Finally, it presents case studies of HVDC implementations for weak grid interconnections in Indonesia.