Seasonal Thermal Energy Storage

With seasonal thermal energy storage, we store the excess heat from your process or solar collectors in summer and recover it for heating your buildings in winter. 

How does Seasonal Thermal Energy Storage Work?

With seasonal thermal energy storage, heat is captured in solar thermal collectors and transferred to specialised boreholes in the earth. This charges the earth with heat in the same way you would charge a battery. The summer heat is stored in the earth until winter, when it can be utilised to heat buildings thus recycling the heat. You don’t need to burn oil or gas for heat, therefore, seasonal thermal energy storage helps to reduce your CO2 emissions.

Can You Store Waste Heat with Seasonal Thermal Energy Storage?

Yes, other sources of heat can also be utilised with seasonal thermal energy storage, such as industrial waste heat, heat from greenhouses or waste heat from energy production. These forms of waste heat are often dumped as they are not useful without having a storage solution available. These forms of heat are free and can replace the need to pay for oil and gas for heating purposes.

Heliostorage Products

Heliostorage provides the technology needed to implement a full solution. This includes solar thermal collectors, a smart thermal controller and our unique borehole thermal energy storage (BTES).

Solar Thermal Collectors


Our solar collectors have a patented profile that allows maximum capture of heat during the entire day. The heat can be sent directly to the buildings hot water tank or to thermal storage for later use.


Our smart controller monitors the heat coming from the solar collectors and the temperatures in the borehole thermal energy storage, sending the heat exactly where it is needed.


The BTES receives heat and utilises that heat to warm the surrounding soil converting the earth into a thermal battery. The core of the BTES remains hot year round and is discharged when needed.

Why Use Seasonal Thermal Energy Storage?

Today in Europe, 50% of the annual energy consumption is used for heating and cooling1. With the current energy crisis, this leaves a big challenge for the months and years ahead. By harnessing heat from the summer sun for later use, we can reduce the demand on other sources of energy, many of which are contributing to climate change. With our seasonal thermal energy storage, we can also store excess waste heat, such as heat from manufacturing processes, greenhouses or energy production, for later use. The heat can be utilised by district heating networks, commercial buildings or even residential units.

Seasonal Thermal Energy Storage
Low-cost heating

No Emissions

Fully emission–free heating
(0g CO2/MWh)

Low-Cost Heating

Cheapest possible heat 

production cost

Continuous Optimization

Storage algorithms are 

continually upgraded

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