Indonesia comprises more than 10,000 islands, and the Indonesian state utility PLN runs several hundred diesel-based small power systems to supply electricity to the majority of inhabited islands. The exorbitant cost of diesel generation has been a long time concern to PLN as well as the Indonesian government, and a shift towards renewable generation promises significant economic advantages on top of the obvious positive environmental impact. Hence, the Indonesian government recently started an ambitious „de-dieselization“ program, with the goal of replacing the majority of diesel-fired generation with PV and battery systems. This is contrasted by the fact that while PV integration in Indonesian islands has been economically feasible for a number of years, only very few hybrid systems operate in the country as of today. The lecture will cover technical, economic and regulatory aspects encountered during Energynautics‘ five year engagement in Indonesia, which involved integration studies in seven different island systems of different sizes.