Dispatch strategies for battery energy storage system integrated with utility scale solar system for contingency reserve service: A Malaysian perspective

The rapid adoption of solar photovoltaic (PV) systems and battery energy storage systems (BESS) has accelerated the global shift to renewable energy (RE). As RE continues to grow, the participation of solar PV plants and BESS (PV-BESS) in ancillary service is essential to ensure grid stability. However, the ancillary services framework related to PV-BESS is not mature in Malaysia. This research assesses the potential of PV-BESS to provide contingency reserve services in Malaysia. A systematic model of PV-BESS with configurable parameters was developed to simulate solar PV generation, BESS state of charge, BESS state of power, and grid export. The study investigated the effects of various dispatch strategies on PV-BESS performance under clear-sky and overcast conditions in Malaysia. A dynamic approach was proposed, demonstrating that allocating 50% of generation from a 2 MW solar PV plant is sufficient to restore a 2 MWh BESS within a day. The study identified the dispatch window and discharge duration that align with the solar generation, maximising the provision of contingency reserve services. The study also demonstrated that a 4 MWh BESS (2 h of solar PV plant’s full export capacity) is required for a 2 MW solar PV plant to discharge at full export capacity of the solar PV plant for 1 h, enabling provision of contingency reserve service at least once per day. These findings can assist stakeholders with scheduling of ancillary services and capacity planning involving PV-BESS in Malaysia. The presented methodology is globally applicable by tailoring to local solar resource data and operational requirements.