Greece is turning a former coal mine into a giant renewable-energy battery; the Kardia project will use the mine’s bottom as a water reservoir to generate 320 MW

Greece is repurposing former lignite mining land in Western Macedonia as part of a renewable energy and storage programme. PPC Group has completed 2,130 MW of photovoltaic projects in Amyntaio and Ptolemaida, with the plants expected to generate 3,150 GWh each year.The company is developing storage facilities that will hold surplus renewable electricity and release it when demand rises. One project at the Kardia mine will use the bottom of the inactive mine as a lower reservoir for a pumped storage system. The facility is designed to have a generation capacity of 320 MW and operate for 8 hours. The programme combines solar generation, battery storage and pumped hydro projects across former mining areas in Northern Greece.How is Greece turning former coal mines into renewable energy sitesPPC Group has completed photovoltaic projects with a total capacity of 2,130 MW in Western Macedonia, using former lignite mine areas in Amyntaio and Ptolemaida. The projects are capable of generating 3,150 GWh, corresponding to nearly 6% of the country’s electricity consumption and meeting the annual needs of approximately 750,000 households.Their operation will prevent more than 1.5 million tons of CO₂ emissions annually. Major projects include the 550 MW ‘Phoebe’ photovoltaic plant near Pontokomi, the 940 MW Amyntaio photovoltaic complex, developed in cooperation with RWE, the 200 MW ‘Helios Velos 1’ plant near Ptolemaida, and the 80 MW ‘Exochi 7’ and ‘Akrini’ plants. Ten smaller photovoltaic stations in former lignite areas will also generate solar energy for thousands of households.How will the Kardia mine store electricity for 8 hoursThe Kardia pumped storage project is being developed in a former mining area after the cooling towers of the units were decommissioned. PPC Group has secured regulatory approvals for the project, which will use the bottom of the former mine as the lower reservoir.It will have a generation capacity of 320 MW for 8 hours. Electricity generated during low-demand periods is used to pump water from the lower reservoir to an upper reservoir, where it is stored as potential energy. When demand increases, the water can flow back down through hydroelectric turbines to generate electricity.Greece expands battery storage to support its growing solar capacityThe Kardia project is part of a storage programme in Western Macedonia. PPC Renewables has completed two electrochemical energy storage stations in Ptolemaida, near Kardia Power Plant, and Meliti, near Meliti Power Plant. Together, the stations have an installed capacity of 98 MW and storage capacity of 196 MWh.Near the Amyntaio Power Plant, a battery energy storage station is under construction, with a capacity of 50 MW and 200 MWh. It is designed to supply electricity to the grid for up to four hours and is expected to be completed in the coming months. The storage systems will support the integration of photovoltaic plants by absorbing surplus generated energy and releasing it when electricity demand exceeds renewable energy generation.How will the South Field mine provide 240 MW of energy storageAlongside the Kardia project, PPC Group is advancing a pumped storage unit in the South Field mine. The project is planned with a capacity of 240 MW for 12 hours and costs €310 million. Both pumped-hydro projects are based in former mining areas and have secured regulatory approvals. PPC describes pumped-hydro storage as an energy storage technology that helps mitigate the intermittency of renewable energy sources and contributes to grid stability.A system has two water reservoirs at different elevations and hydroelectric turbines. During low-demand periods, electricity is used to pump water from the lower reservoir to the upper reservoir. When demand increases, water is released through turbines, generating electricity. The projects repurpose inactive mining sites for storage.You use AI every day. Now get your AI Quotient. Take the AIQ test.