IN Brief:
- The agreement covers separate 200MW/800MWh batteries at Ełk and Turośń Kościelna.
- Both projects have 17-year Polish capacity market contracts beginning in 2028.
- The agreed sale to A&R Investments is expected to complete by the end of 2026.
Greenvolt Group has agreed to sell two large battery storage facilities in north-eastern Poland to Malta-based investment company A&R Investments, transferring a combined 400MW of power capacity and 1.6GWh of energy storage once the transaction is completed. The agreement covers the Ełk and Turośń Kościelna projects, each rated at 200MW/800MWh, and is expected to close before the end of 2026, subject to customary transaction conditions.
Although Greenvolt identifies both facilities as completed during the third quarter of 2026 and permitted for use, those milestones should not be confused with identical commercial operating dates. Turośń Kościelna was inaugurated on 30 July, while the developer’s September update still expected commercial operation at Ełk in the fourth quarter. The transfer of ownership remains a separate transaction, subject to closing conditions.
A 200MW power rating represents the maximum rate at which each battery can deliver electricity, while its 800MWh energy capacity measures the amount available over time. At its rated output, each installation can theoretically discharge for around four hours before its usable energy is exhausted. Actual dispatch depends on operating limits, the state of charge, auxiliary consumption, losses and the need to preserve availability for future obligations.
The two sites have secured 17-year agreements under Poland’s capacity market, beginning in 2028. Each contract provides a fixed payment associated with making 85% of the battery’s rated power available to the system. For a 200MW installation, that percentage corresponds to a 170MW capacity obligation; it is not a claim that the facility must deliver a continuous 170MW for the entire contract period.
Both projects are also covered by a 10-year tolling agreement for the trading and optimisation of their flexibility, Greenvolt said. Such arrangements can allocate the commercial right to determine charging and discharging schedules to a counterparty, subject to defined operating limits and payments. The announcement does not identify the tolling counterparty, explain whether there are separate agreements for each asset, or disclose how the revenues and operational responsibilities will be divided.
The capacity market and the tolling agreement remunerate different aspects of battery operation. Capacity payments depend on qualifying availability under Poland’s market rules, whereas trading arrangements can capture changes in wholesale electricity prices and demand for flexibility. Any use of the batteries for balancing services must be coordinated with their state of charge, connection limits and the capacity obligations already contracted for 2028 onwards.
Turośń Kościelna gives an indication of the engineering equipment behind those services. The installation uses lithium iron phosphate battery technology supplied by BYD Energy Storage and connects to Poland’s 110kV network. Greenvolt has said the site can respond to operator signals within seconds. Fast electrical response is useful for balancing services, although the energy available for sustained delivery remains limited by the storage capacity and the operating state of the battery.
The Ełk project was previously described as connecting at 220kV, reflecting a different grid interface from Turośń. The voltage at the connection point influences the transformers, switchgear, protection systems and associated electrical works needed to transfer power between the battery converters and the transmission network. It does not, by itself, establish which market services a project will provide after commercial operation begins.
With two 200MW batteries connected to the Polish system, the projects can potentially move a substantial quantity of electricity between periods of generation and demand, once their applicable operating arrangements are in place. Their bidirectional converters draw electricity from the grid when charging and export it again during discharge, less conversion and storage losses. The energy rating limits how long that service can be sustained; it does not guarantee that the full output will always be available to the network.
A&R Investments is an investment vehicle based in Malta, managing a portfolio of public and private assets. Greenvolt did not disclose the sale consideration or provide a detailed post-completion management structure. Until closing, the announcement represents an agreed transfer rather than a completed change of ownership.
Greenvolt has a wider battery pipeline of approximately 4.6GW across its markets. Its Polish programme also includes the 600MW/2.4GWh Siedlce project, which entered construction in September and is scheduled for commercial operation by the end of 2027. Siedlce is separate from the two facilities being sold and remains an indication of Greenvolt’s continuing development activity in the country.
The proposed sale follows Greenvolt’s asset rotation strategy, under which the company expects to sell approximately 70–80% of its internally developed projects and reinvest the proceeds in new developments. No sale consideration has been disclosed. Closing is expected before the end of 2026, while the projects’ 17-year capacity obligations begin in 2028 and will need to be managed alongside their tolling arrangements.
