Turośń Kościelna, which connects to the grid at the 110KV level, and Nowa Wieś Ełcka, which is connected at the 220kV level, were both part of Greenvolt’s 1.2GW Polish capacity market win.
Run in late 2023 and awarded in early 2024, the capacity market for delivery beginning in 2028 awarded a total 1.7GW of contracts, after an auction that cleared with a fixed consumer price-indexed (CPI) price of PLN 244.90/kW (~US$61.73 at the time) per year.
Greenvolt’s win of the lion’s share of capacity comprised four BESS projects in total. Its contract for Turośń Kościelna Battery Energy Storage Facility runs for a 17-year term with a 170MW capacity obligation, or 85% of the nameplate BESS output.
Greenvolt’s deputy commercial director for Europe spoke to ESN Premium about the CM wins in October 2024, who said the solicitation was “the most intensive and costly exercise in my career but it paid off.”
“We were on a steep learning curve at the time and acquired the projects fairly late-stage. The CM is not a natural hunting ground for renewables developers and management is often a bit conservative around it, but at the end of the day it is a boon for financing,” Greenvolt’s Jan Kloczko said.
De-rating cut drives CM pullback
Poland’s first CM auction in late 2022-2023, for which BESS was eligible to compete, awarded 165MW of contracts, followed by a tenfold increase the following year. In the 2024 auction, for the 2029 delivery year, 2.5GW of energy storage project bids were selected.
However, in the most recent auction, run in December 2025, energy storage participation fell, with just 685MW of wins for BESS projects. Energy-Storage.news heard from developer Harmony Energy and consultancy Arthur D. Little that this was largely due to a sharp cut in the de-rating factor of BESS in the auction design, from 95% in 2023, to 60% in 2024 and just 13% last year.
Turośń Kościelna marks Entrix’s first BESS optimisation in Poland. The energy trader signed an exclusive agreement with Greenvolt in September 2025 to trade a total of five large-scale BESS for the IPP in Poland, including the two aforementioned projects and totalling 1.3GW/5.2GWh.
Entrix will use its AI-based multi-market optimisation solution to select and bid into balancing services such as Frequency Containment Reserve (FCR) and Automatic Frequency Restoration Reserve (aFRR) ancillary services, as well as day-ahead and intraday trading in the wholesale markets.
Greenvolt is set to start building what it claimed will be Poland’s biggest project in Q3, the 600MW/2,400MWh Siedlce BESS project, which is also capacity market-contracted. Greenvolt also signed a deal with BYD to supply BESS equipment for Siedlce a few weeks ago. BYD will supply its ultra-high-energy-density 10 MWh, 20-foot container Haohan BESS solution. According to Benchmark Mineral Intelligence, BYD was the leading energy storage system integrator by global shipments in 2025, with a 13% market share.
Last month, the IPP inaugurated what is currently Hungary’s largest operational BESS project.