Have you tried seasoning your energy storage with salt?

The adoption of the EU’s ambitious target to increase the share of renewable energy in overall energy consumption to at least 42.5% by 2030 by the private and public sectors has triggered remarkable innovations.

"Being part of this project makes me proud because I can make a small contribution in building a better world." 

The ongoing transition to renewable energy sources results in large fluctuations in supply and demand, underscoring the importance of energy storage. An affordable, compact, and sustainable solution, where the storage of energy supply is based on demand levels, might be one of the answers. 

HEAT-INSYDE, an EU-funded project, is a consortium featuring 11 academic and commercial partners – initiated by the Eindhoven University of Technology, The Netherlands Organization for Scientific Research, and the Caldic Benelux team. They have developed loss-free storage for heat energy in the form of a ‘heat battery’ consisting of a vessel in which salt (potassium carbonate) is hydrated, creating thermochemical energy.


When dehydrated, the energy is stored in the salt itself and can be stored indefinitely with no loss from leakage or the conversion process. It is designed to use thermal energy (heat) from the environment to evaporate the water so that little to no energy levels are required to store the heat energy in the dry salt crystals. The system can be combined with geothermal or solar thermal sources, or the heat from industrial waste valorization. The heat battery can also be used to improve the efficiency and decrease the power demand of a heat pump.


Henry van der Meer, Product Manager Specialty Chemicals at Caldic Benelux has been involved in the project since its commencement in 2020. Our technical experts have been supporting the design of the battery by identifying potassium carbonate as the suitable thermochemical materials to optimize the production process – thereby ensuring that the system is able to store heat without loss, and also supplies the salt and the coating for its granules for the battery to the consortium.


The first use case testing was performed at a rental residential house in Eindhoven, the Netherlands, in a special state-of-the-art shed that harvests heat from the surroundings. The HEAT-INSYDE systems were later installed in Cadenet, France, and Gdynia, Poland. The different use case locations vary in climate and heating requirements – allowing it to be tested effectively.


In its final phase, the HEAT-INSYDE project aims to make the transition to renewable energy more efficient and affordable. We are proud to actively take part in this innovative industry research initiative that perfectly aligns our solutions with our sustainability ambitions. Our experts’ focus on the unique characteristics of specialty chemicals enables us to support our business partners in identifying product solutions that help deliver a positive impact on our planet particularly in the context of accelerating the deployment of renewables.

"At the heart of HEAT-INSYDE was finding the right thermochemical material for the heat battery, which our technical experts thoroughly investigated before their selection. As the project reaches new heights, the extensive use of the batteries also means a new market for Caldic, maintaining the balance between our growth and sustainability objectives," - Henry van der Meer.