This report was prepared on the basis of the framework for collaboration established by the International Energy Agency (IEA) and the Ministry of Energy and Mineral Resources (MEMR) of Indonesia on the topic of power system enhancement and renewable energy integration, and in support of the implementation of the upcoming Presidential Decree on renewable energy. It is part of the assistance provided by the IEA towards Indonesia’s efforts to reform its energy sector and is consistent with IEA’s forthcoming Energy Sector Roadmap to Net Zero Emissions in Indonesia. The overarching objective of the assignment was to assist Indonesia in tackling short-term power system challenges, by achieving key targets such as reaching a 23% share of renewable energy in the national electricity mix by 2025 in a secure and affordable fashion, and by making grids progressively smarter. The assignment included the organisation of a number of workshops for Indonesian stakeholders and a techno-economic study performed by the IEA. It benefited from the support of the state-owned utility Perusahaan Listrik Negara (PLN). This public report summarises the information gathered from the workshops and presents the results of the study in a set of recommendations for Indonesia.