Refining the grid: fine-tuning renewable energy generation and transmission for optimal electricity supply

Energy losses in electricity transmission networks pose a challenge, often requiring excess generation to meet demand. This study investigates an optimisation framework to reduce such losses and improve overall energy system efficiency by balancing renewable generation, storage, and transmission. Using Indonesia’s Java–Bali network profile in 2020 as a case study, the framework integrates generation from five renewable sources (solar, wind, geothermal, hydro, and municipal solid waste) with local potential energy storage, existing transmission infrastructure between provinces and domestic demand data. The results are obtained from a sequence of linear programs using hourly demand–supply data for the lowest production period in 2020, i.e. the first week of April. During this period, the province of West Java outperformed other provinces, generating approximately 3.2 GWh of renewable energy and thereby reducing dependence on storage and imports. In contrast, East Java, despite producing 2.7 GWh, required 0.6 GWh from storage to meet its demand. At the end of the week, Jakarta imported 1.5 GWh from Banten and 0.1 GWh from West Java to offset local deficits. These results indicate that the current installed generation capacity, energy storage, and transmission network can provide a reliable electricity supply even during periods of minimal renewable production. Scenario analysis further demonstrates that optimised combinations of renewables, storage, and transmission could satisfy up to 235% of the domestic demand during the analysed week without expanding installed renewable capacity. These findings highlight the potential of maximising system efficiency within existing infrastructure and offer a transferable framework for managing energy transitions in other regions worldwide.