Thermal energy storage allows thermal energy to be collected for later use. This can be hours, days or many months later and is achieved with different technologies. Thermal energy storage can be valuable and applicable for an individual building, a large multiuser building as a school or hospital, district or local area and even a complete town. With the help of thermal energy storage, energy demand can be balanced between day and night or summer and winter. For example, heat from the sun can be stored for use in winter, cold from winter air can be used in summer.

Seasonal thermal energy storage

Seasonal thermal energy storage, also known as STES, is the common term for several technologies for storing heat or cold for longer periods of times. Thermal energy can be collected whenever it is available and can be used whenever needed. A less common term for seasonal thermal energy storage is interseasonal thermal energy storage.

Seasonal thermal energy storage in greenhouses

Seasonal thermal energy storage is also used extensively for the heating of greenhouses. Aquifers are the common used kind of storage system. In the summer, greenhouses are cooled with ground water pumped in the aquifer. In this process, the water is turned from cold into hot water. When the greenhouse needs heat, water is withdrawn from the warm well. While serving its heating function the water will cool down and will be pumped into the cold well.

Ecovat® energy storage system

Ecovat® is an innovative, large thermal energy storage system with an extremely good storage capacity and longevity. The thermal energy in an Ecovat® is produced by cast-in-ground cylindrical volumes in which modular building standard wall sections are positioned. The heat exchange within the vessel takes place through heat exchangers integrated in the wall. With greenhouses,  different types of energy sources and waste heat will be used for thermal energy storage. With this storage system which functions as a big buffer tank,  heat and cold can be stored and circulated deep below the ground.

seasonal thermal energy storage

The different segments in the Ecovat® vessel can be charged and discharged at different temperatures. On the one hand, this allows a higher average temperature to be stored in the vessel. On the other hand, the temperature will be optimally adapted to the situation.

Are you interested to know more? Please do not hesitate to contact us for more information or to make an appointment for a guided tour in our Zero-energy office building.

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