Estonian solar park enters Baltic frequency markets
Eesti Energia and Emsys VPP have prequalified the 75 MW Sopi solar park to deliver 30 MW to the Baltic region’s automatic frequency market and 45 MW to its manual frequency market.
June 19, 2025 Patrick Jowett
Estonian publicly owned energy utility Eesti Energia and German virtual power plant provider Emsys VPP have prequalified the 75 MW Sopi solar park for participation in the Baltic automatic and manual frequency markets.
The project, operated by Eesti Energia’s Enefit Green, was completed earlier this year and is located in Pärnu county, southwestern Estonia.
Following testing with system operator Elering, the solar park is approved to deliver 30 MW to the automatic Frequency Restoration Reserve (aFRR) market and 45 MW to the manual Frequency Restoration Reserve (mFRR) market. It is the largest solar project in the Baltics to qualify for participation in both markets to date.
Kristjan Kuhi, member of the management board at Eesti Energia, said the achievement marks a significant step in integrating renewable energy into frequency markets, as it will be crucial for maintaining grid stability in the Baltic electricity system.
“The Sopi solar park is part of our virtual power plant, which integrates various production and consumption assets and enables real-time frequency control,” said Kuhi.
Participation in frequency markets allows renewable energy production facilities to support grid frequency stability. Eesti Energia and Emsys VPP said the more flexible and fast-responding production assets available on the market, the less need there is for backup reserves, helping to keep electricity prices lower.
“This also enhances the energy security of the Baltic region by enabling greater reliance on local renewable sources and reducing the need for imports,” the statement added.
The Baltic states synchronized their electricity system with the Continental European frequency area in February 2025, making the three countries responsible for maintaining regional balance between generation and consumption.
This effort is supported by Enefit Power’s dispatchable plants in Estonia, solar and wind parks managed by Enefit Green across Estonia and Lithuania, and Estonia’s first large-scale battery storage facility, which opened earlier this year.
Estonia deployed 513 MW of solar in 2024 – a record in a calendar year for the country.