Ecovat is an innovative, large thermal storage system with an extremely good storage capacity and lifespan. The thermal energy storage in the Ecovat is created by heating the water in the tank, for instance from 10 to 90 degrees. This heat will remain in the tank for 6 months with less than 10% heat loss.

Heat exchange takes place through heat exchangers that are attached to the wall of the tank. The modular construction and heat exchange of Ecovat are patented parts.

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Thermal energy storage with ‘container-in-container principle’

The Ecovat is built on the basis of the ‘container-in-container principle’. In the outer tank an insulated inner tank is placed. This inner tank is made from prefab wall parts. To the wall parts of the inner tank heat exchangers are attached. Compared to other systems for thermal energy storage, the Ecovat attains the highest preservation of energy and the highest efficiency. Because the heat is exchanged via the tank’s inner wall, no water is required to be transferred by pump.


ecovat development

“In the transition to a 100% sustainable energy system, storage is the missing link.”

Working principle of the heat exchangers

The water that runs through the heat exchanger, is pumped around and along heat generators. The temperature generated subsequently heats the heat exchanger. Through conductivity this heat is emitted to the water in the tank. Conversely, during discharge the cold return pipe of the heat grid is connected to a warm stratum in the Ecovat and sent back to the heat grid in a warm state.

High quality of energy because of thermocline

This way, the natural stratification of the water is not disturbed and up to 40 percent more energy is retained. The buffer’s efficiency is optimized by maintaining the sharpest ‘thermocline’ possible. Thus, the energy in the Ecovat has the highest quality. This enables conservation of energy with the highest energy quality for the transition from summer to winter.