A PLEXOS generation expansion model for interconnected Philippine main grids

The Philippine power grid is composed of three major grids: Luzon, Visayas, and Mindanao. While the Luzon and Visayas Grids have been interconnected since 1998, the Mindanao grid was considered to be isolated until the establishment of the Mindanao-Visayas Interconnection Project (MVIP) in 2023. A simplified model of the Philippine grid was built in PLEXOS across a planning horizon from 2022 to 2040. Different scenarios were established for the model by varying the transfer capacities of the Luzon-Visayas and Visayas-Mindanao interconnections. Key parameters such as generation mix, levelized cost of electricity (LCOE), capacity expansion, and transmission line flows were analyzed for each scenario. The obtained results, given the assumptions and data used for building the model, showed that interconnection enables higher share of wind and solar power in regions with better availability curves such as Luzon and Visayas to achieve the RE targets and lower LCOE. This transforms Visayas into a net power exporter, sending surplus power to Luzon and Mindanao due to their lower demand. Meanwhile, unlimited transfer capacities essentially unify the grids, allowing Visayas and Mindanao to contribute to meeting Luzon’s high demand. These indicative results illustrate what the model can do given publicly available data and some model assumptions. Areas for future work include modeling of generator capacity contribution for reserves and transmission line losses and costs, as well as modeling the major grids by decomposing them into interconnected regional nodes.