olls-Royce Power Systems and Sunly, a renewable energy company operating in the Baltic region, have formalised contracts for the construction of four large-scale battery storage facilities in Latvia, totalling 490MW-hours (MWh) of capacity.
The signing was announced at the opening of Sunly’s new solar park in Valmiera, one of Latvia’s first hybrid energy parks.
The first of the battery systems, located in Valmiera, is due to be operational in the first quarter of 2027 (Q1 2027), with the remaining three projects due to follow later the same year. Under the agreement, Rolls-Royce will deliver a full solution using its mtu EnergyPack system alongside its mtu EnergetIQ software platform. These technologies manage energy storage and release to support grid stability and help balance supply and demand. nRolls-Royce will act as general contractor, providing a single point of responsibility throughout the design, supply and construction process.
Rolls-Royce Power Systems mobile and sustainable business unit president Andreas Görtz comments:
“As a general contractor, we offer our customers a single point of contact, which helps them reduce risks and complexity, ensure profitable performance and maximise long-term asset value. Together with Sunly, we are delivering large-scale battery storage systems that will play a crucial role in strengthening grid stability and energy security in the Baltic region.”
Sunly selected Rolls-Royce based on previous experience in the region and the company’s ability to meet technical and cybersecurity requirements.
The partnership will continue beyond Latvia, with both parties having signed a memorandum of understanding for an additional 300MWh battery storage project in Risti, Estonia.
Sunly CEO Priit Lepasepp explains:
“Our aim is to build an energy system that serves people – not just when the sun is shining. By combining solar power generation with battery storage, we can supply energy when it is needed. This makes renewable energy more reliable and less dependent on the weather. We have to meet strict cybersecurity requirements. It was therefore crucial for us to find a European partner that has already demonstrated its expertise in Latvia.”
Rolls-Royce Power Systems currently reports supplying mtu battery storage solutions for more than 200 projects globally. In the Baltic region, it expects its battery storage installations to exceed 1.5GW-hours once contracted projects are completed. Another battery storage system from Rolls-Royce has been in operation in Latvia since 2025 for transmission system operator Augstsprieguma Tikls.
Augstsprieguma Tīkls (AST) is an independent electricity transmission system operator in Latvia. It operates power systems with voltages of 110 kV and above and is responsible for ensuring the security of electricity supply in Latvia. AST was established on October 15, 1939, and was unbundled from Latvenergo in 2012. In 2025, AST reported a revenue of EUR 266.01 million, with significant investments in the development of the electricity transmission grid and synchronisation with the European energy system.
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