The Maha Oya Pumped Storage Power Station is a 600 being developed in the and areas of . Upon completion, it will be the country's first facility, and one of the in terms of nameplate capacity. The Maha Oya facility is designed to store excess renewable energy from solar and wind sources, thus creating supporting infrastructure for Sri Lanka's target of generati. The Ceylon Electricity Board (CEB) has announced that it is making substantial progress in launching the Maha Oya Pumped Storage Hydropower Project, marking Sri Lanka’s first-ever large-scale energy storage system, often referred to as a “Water Battery.”
[pdf] The project will introduce Sri Lanka’s first grid-scale battery energy storage system at the transmission level, establish a renewable energy center to forecast and monitor renewable energy generation, the ADB said.
[pdf] The Ceylon Electricity Board (CEB) has requested proposals for a standalone battery energy storage system initiative. The purpose of the facility is energy shifting and the utilization of renewable energy. A secondary objective is contribution to frequency response during emergencies.
[pdf] 
