Mitigation of Solar Intermittency Using Battery Energy Storage Systems, as a Case Study for Sri Lanka

Renewable energy resources play a major role in the process of sustainable development of a country. However, increased integration of renewable energy resources into the system requires careful planning to maintain the system's resilience. It has been proposed to integrate 1,000 MW of solar capacity into the Sri Lankan network by 2025. Frequency stability studies reveal that absorption of proposed solar power into the national grid is not possible with the present generation mix. Therefore, battery energy storage systems are proposed to be integrated into the system to maintain system stability while absorbing 1,000 MW of solar power. A battery capacity of 150 MW is identified as a sufficient amount to maintain the frequency stability, and the study proposes to commission the energy storage as 50 MW each at Kolonnawa, Kappalturei and Hambantota grid substations to achieve the minimum power loss.