It is a heat accumulator that can store 2MWh at 600°C. It is made from refractory ceramics from the circular economy. Its operation is simple: hot fumes from the chimney is sucked in and sent to the Eco-Stock®, storing energy by heating ceramics. Thanks to a modular "Plug and Play" system, the heat can be used directly on site or transported to another site or a landfill.