Greenvolt, the Lisbon-headquartered renewables developer owned by KKR, and Statkraft, Norway’s state-owned power company, signed a ten-year tolling agreement on Tuesday 29 September covering 400 MW / 1.6 GWh of battery storage at two projects in north-eastern Poland. Both are four-hour batteries of 200 MW / 800 MWh: Ełk, at Nowa Wieś Ełcka, and Turośń Kościelna, in the municipality of the same name. According to the two companies it is the largest tolling agreement for battery energy storage publicly communicated in the European Union to date, and it is Statkraft’s first large-scale battery contract in the Polish market.
Under a tolling structure the owner rents out what the battery can do rather than trading it itself. Greenvolt keeps ownership of both projects; Statkraft acquires the right to decide when the batteries charge and discharge across Poland’s energy and flexibility markets. In return Greenvolt receives a predictable, long-term income that sits alongside the revenue it has already secured through Poland’s Capacity Market. Neither company disclosed the value of the contract.
“This agreement with Statkraft brings sophisticated market optimisation to these projects, allowing the flexibility of the batteries to be monetised across different power markets and unlocking additional revenues,” said Łukasz Zagórski, business origination and market regulation director at Greenvolt Power, adding that “as we move further along the value chain, with projects now entering operation, choosing the right commercial structure is increasingly important.” For Statkraft, Kornel Koronowski, head of origination in Poland, called it “the largest BESS transaction signed in the country to date” and said the two batteries complement a portfolio of third-party wind and solar assets from which Statkraft offers stable prices to energy-intensive buyers. Statkraft had previously signed what it describes as Poland’s largest corporate PPA and the country’s first subsidy-free utility-scale solar PPA.
One battery running, one about to start
The contract arrives as the assets come online. According to the trade publication ESS News, Turośń Kościelna was inaugurated in July 2026 and Ełk is expected to reach commercial operation shortly; the battery systems were supplied by BYD Energy Storage. ESS News also reports that the tolling deal was not needed to finance construction: Greenvolt had already secured €153 million of bridge facilities and a €65 million guarantee facility from UniCredit in August, and Capacity Market payments for Turośń Kościelna begin in 2028. What the Statkraft agreement changes is the exposure to market prices. Four-hour batteries on a grid that still leans heavily on coal while adding wind and solar earn their keep by shifting power from cheap hours to expensive ones and by selling balancing services. Handing that trading to a utility with a large portfolio and its own risk desk turns volatile arbitrage income into a contracted payment.
A Portuguese company with a Polish engine room
Greenvolt began life as the renewable-energy arm of Altri, the Portuguese pulp group, and listed on Euronext Lisbon on 15 July 2021 with an IPO of about €150 million. Alongside the listing it raised a further €56 million in a reserved capital increase used to buy V-Ridium, a Polish developer that became Greenvolt Power — the utility-scale platform that signed this week’s contract. In 2024 a vehicle controlled by KKR took the company over: the mandatory bid closed in October with 97.64 percent of the shares, and Greenvolt left the Lisbon exchange in November after KKR bought out the remaining holders. The group now describes itself as operating in 20 geographies across three businesses: sustainable biomass, with seven plants in Portugal and the United Kingdom; utility-scale development, with a 12.8 GW pipeline of wind, solar and storage; and distributed generation, with more than 1 GW of contracted capacity in 12 countries.
A second Nordic trading partner for Greenvolt’s batteries
Poland is not the first place where Greenvolt has put a Nordic counterparty between its batteries and the market. At its Høegholm hybrid park in eastern Denmark — solar paired with a 60 MW / 120 MWh battery and financed by Ringkjøbing Landbobank — balancing and optimisation were contracted to Copenhagen-based power trader Reel, as NorthSouth HQ reported in May. The Statkraft contract is a much larger version of the same arrangement: a Portuguese developer builds the hardware, and a Nordic energy company with a trading desk sized for the job takes the market risk.
For Statkraft, wholly owned by the Norwegian state and describing itself as Europe’s largest producer of renewable energy, the Polish batteries add flexibility to a book built on selling wind and solar output to industrial customers under long-term contracts — the capability that intermittent generation on its own cannot provide.
Why this matters for the corridor
Most of NorthSouth HQ’s energy coverage runs south: Nordic utilities, pension-backed funds and turbine makers putting money and machines into Iberia. This deal runs the other way. A company founded and still headquartered in Lisbon has developed 1.6 GWh of storage in a third market and signed a Norwegian state company as its long-term commercial partner — the kind of counterparty that lenders and future buyers of the assets can price. For Portuguese developers weighing Nordic partners, the lesson of both Høegholm and Ełk is that Nordic utilities and traders matter as much as buyers of flexibility as they do as investors, and that they will sign for a decade.
Sources: Statkraft and Greenvolt announcement of 29 September 2026 as reported by Energy Global, Jornal Económico, Jornal de Negócios and Executive Digest; ESS News (29 September 2026) for commissioning, supplier and financing details; Altri and Euronext statements on Greenvolt’s July 2021 IPO; ECO (21 November 2024) and Euronext on the KKR takeover and delisting; NorthSouth HQ coverage of Høegholm (May 2026).