EXECUTIVE SUMMARY

Estonian renewable energy developer Sunly has commissioned a 21 MW/48 MWh battery energy storage system (BESS) at its Raba hybrid energy park in Põhja-Pärnumaa rural municipality, Estonia. The newly completed battery facility operates alongside a 45 MW solar power plant commissioned in 2024, enabling renewable electricity generation and storage within a single integrated energy park.

The Raba solar plant produces approximately 47 GWh of electricity annually, equivalent to the yearly consumption of around 13,000 households. The battery system stores surplus electricity generated during periods of high solar production and supplies it to the grid when demand increases. This configuration allows renewable electricity generated during midday to be delivered during evening consumption periods.

According to Sunly board member Erkki Kallas, battery storage integration was considered during the project's initial development to address the growing importance of electricity availability as solar and wind generation expand. The hybrid configuration is intended to improve coordination between renewable electricity production and consumption.

Raba is Sunly's first completed hybrid park connected to Elering's 110 kV electricity network, where solar generation and battery storage share a common grid connection. Smartecon was responsible for network testing to verify that the solar plant, battery system and electricity grid operate together as planned.

The Raba project was developed in cooperation with Metsagrupp OÜ, with Luminor Bank serving as its financing partner. Under a local community support arrangement, Sunly contributes 0.6% of the solar plant's annual sales turnover to Põhja-Pärnumaa municipality.

Sunly is also developing the Nurme hybrid energy park in Seljametsa village, Pärnu County. An 8 MW/20 MWh battery storage facility is scheduled for completion alongside the Nurme solar park in November. Both Raba and Nurme have been developed with Metsagrupp OÜ and financed by Luminor Bank.

Beyond battery storage, Sunly is developing the Maima wind farm in Põhja-Pärnumaa, comprising up to eight turbines with a combined capacity of 56 MW. The proposed project could generate electricity equivalent to the annual consumption of nearly 59,000 households.

The company is also advancing the planned 42 MW Põlendmaa wind farm in Pärnu, consisting of six turbines.

Sunly develops solar, wind and battery storage projects across the Baltic States and Poland. Its hybrid energy park strategy focuses on integrating renewable generation, electricity storage and consumption to improve grid flexibility, support energy security and expand domestic renewable electricity supply.