Java and Bali, Indonesia, has significant renewable energy potential that can support cleaner power and fair access to electricity. However, progress is slowed by limited electricity access in rural areas, slow renewable rollout, and limits in the power grid. This thesis looks at household electricity demand and investigates how different renewable energy combinations, energy storages, and power transmission network can improve the Java-Bali energy system, while also offering solutions for rural areas. The results show that wind-based energy mixes give the best balance between cost and environmental benefits. To balance power supply and demand, the study compares storage options and finds that off-river pumped hydro storage performs better than batteries and compressed air systems. Better coordination of power generation, storage, and regional power exchange can also cut losses and improve reliability. For remote areas, hybrid renewable systems offer a cheaper and more practical solution than extending the grid. Overall, Indonesia’s energy transition is achievable with smart planning and the right technologies.