Underground energy storage gains in popularity

Thermal energy storage (TES) systems can store heat or cold in the ground to be used later to heat up or cool down buildings. It’s a technique that has gained in popularity over recent years, which is no surprise when you consider the substantial energy savings it can lead to.

How does it work?

Heat is extracted from the building and stored in water-bearing layers or ‘aquifers’ in the ground to cool the building down in the summer. And in winter this stored heat can be used to heat buildings. Because the heat is stored at a relatively low temperature, it is brought up to the desired temperature using a heat pump. TES installations use two (drilled) sources: in summer, water is extracted from the cold source to cool down the building via a heat exchanger before the heated water is stored in the hot source; and in winter it’s the other way round. To be able to keep doing this year on year, it’s important to extract as much heat from the ground as is loaded into it on an annual basis. It needs to be balanced.

What’s Hysopt doing with this?

Because thermal energy can lead to significant energy savings, at Hysopt we’re working hard to integrate this in our software. We’re currently developing various base circuits to calculate, simulate and optimise these complex installations. We’re also creating the necessary templates for combining these different base circuits to produce working installations that include all the control logic. This means the designer no longer needs to start from scratch, and can continue building on the system concepts that are already available. We will release this in our software in April 2019.

Own specialist in house

We have our own TES specialist in house to ensure it’s a success. Jonas Cleiren, Engineering Consultant at Hysopt, wrote his thesis on this topic. And the ‘Hydronic design of heat and cold production systems with geothermal seasonal storage’ didn’t just score well at the University of Antwerp; it also earned him a place among the finalists for the Encon Energy Prize and the ATIC Marcel Herman Prize – an annual award for students who wrote a very interesting thesis.