Hybridisation of diesel small grids in Papua New Guinea

Papua New Guinea (PNG) has one of the lowest electrification rates in the Pacific, with only 15% of the population having access to electricity. Smaller grids in remote towns are outdated and provide an unreliable service with frequent load shedding and unplanned outages. This paper summarises the characterisation of the major problems identified in four small grids, analyses the technical assessment results and proposes a retrofit for the generation and distribution assets. The current condition of the power generation infrastructure forces an almost complete upgrade. The proposed solution encompasses a hybrid system based on solar PV, a Battery Energy Storage System (BESS) and diesel generators. High renewable penetration requires large capacities for energy shifting. The main barriers to such a system are high technology and civil works costs, limited land availability and relatively low fuel costs at some sites. As a result, a hybrid system targeting a 30-40% solar fraction was selected, with diesel generators keeping the grid-forming role and BESS providing ancillary services and reducing the need for generator spinning reserves. Grant funding plays a decisive role in making the retrofit financially appealing, but hybridising the generation reduces operational risk and enhances tariff stability while decreasing dependence on fossil fuels.