Slovenia utility DEM plans 60MW battery storage co-located with hydroelectric plant & new PHES unit

February 8, 2023
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Slovenia state-owned utility Dravske elektrarne Maribor (DEM) is planning two battery storage units totalling 60MW co-located with an existing hydroelectric unit, as well as a new pumped hydro energy storage (PHES) plant.

CEO Damjan Seme gave the updates in an interview released on DEM’s site last week (31 January), in which he spoke at length about the energy transition in the country, which borders Italy, Croatia, Austria and Hungary. DEM is part of the larger state-owned power group HSE Group.

Seme said that the company last year submitted a building permit application for the installation of two 30MW battery energy storage systems at the Mariborski Otok Hydro Power Plant, which also has a power capacity of 60MW. He expects the permit to be granted within the first quarter of 2023.

He added that it was still to be decided whether the battery storage units would only provide services required within the HSE Group’s network, which includes various power generation units as well as energy trading in Slovenia and internationally, or “more widely on the market”.

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2022 also saw DME produce a feasibility study for the 440MW ČHE Kozjak pumped hydro energy storage (PHES) project. He didn’t reveal the planned capacity of the project but PHES typically has a duration of 6-20 hours implying anywhere between 2.6GWh and 8.8GWh.

“The continuation of the ČHE Kozjak project was extremely accelerated last year, the “frequency” of activity rose sharply due to the needs for the responsiveness of the power system, the needs for the supply of electricity to the market and, last but not least, the need for such a production unit due to the reliability of the network in relation to new consumers and new production units from renewable sources, which represent volatile sources,” Seme said.

He concluded that “…we must all do everything together to ensure” that the unit goes online by the end of the decade.

Energy-Storage.news covered two battery storage projects in Slovenia a few years ago totalling 52MWh of capacity developed by local firm NGEN, while the country is also participating in a 50MWh battery storage trial aimed at increasing grid flexibility between it and neighbour Croatia.

Energy-Storage.news’ publisher Solar Media will host the eighth annual Energy Storage Summit EU in London, 22-23 February 2023. This year it is moving to a larger venue, bringing together Europe’s leading investors, policymakers, developers, utilities, energy buyers and service providers all in one place. Visit the official site for more info.

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