Back to Search

International Partner Search

Innovation & Technology Offer

New ecological and cost-efficient Heat Storage Material (HSM) for thermal energy storage solutions

Country of Origin: Germany
Reference Number: TODE20190227002
Publication Date: 13 March 2019


The German SME develops, produces and sells an innovative Heat Storage Material (HSM). It is used e.g. in wood stoves and reduces their emissions, increases their thermal efficiency and expands their field of application from solely single room heating to central heating. The company is looking for partners for research and technical cooperation agreements as well as license, manufacturing and commercial agreements to further develop and promote the innovative material.


The founder of the German company worked in the fields of building construction and energy saving since 1989. In 2010 he started together with colleagues an environmental research and development project on heat storing materials. The company is based in southern Germany.

In 2015, stove and material developed by the German SME have been evaluated in a scientific setting by a renowned German Research Organisation (RO), which accredited the heat storing material an excellent long-term stability and an efficiency at least 30% higher than chamotte. In a joint development project with the RO (funded by national funds), the material composition and processing were further improved thereby enabling other applications, e.g. emission reducing built-in components for stoves, and solid heat storing material for general usage.

Wood-burning stoves are traditionally equipped with chamotte (fireclay) which has a poor life cycle assessment (twice sintering/burning = high CO2 footprint) and is very inefficient when used as heat storage (low heat capacity and thermal conductivity, both at least 30% less than the HSM). Products by competitors additionally contain graphite, soapstone and other substances to improve their heat conductivity. They attempt to compensate the persisting low specific heat capacity by compressing it (higher weight, material consumption and price). However, these materials are still inefficient because their heat capacity stays 30-50% below that of the HSM - as measured by the German RO.

Compared to chamotte, the HSM shows its advantages:
• 30% cheaper because of simple production without burning/sintering/compressing
• 30% higher efficiency because of higher heat capacity and perfectly fitting heat conductivity
• 30% less wood consumption (also resulting in the reduction of CO2, soot and particulate matter)
• 70% less CO2 emissions during production, because burning/sintering is not necessary
• 70% less soot and particulate matter emissions using built-in components made of the HSM
• 70% less premature deaths (100,000 -> 30,000) due to reduced particulate matter pollution

Quantitative data comparison of the HSM to current state-of-the-art heat storing materials of competitors shows that the HSM not only has better physical properties like higher heat absorption and storage, but is also cheaper than state-of-the-art solutions. Higher specific heat capacity is better AND should match with higher heat conductivity, otherwise efficiency of the materials heat storage is low because of its rapid heat dissipation. Lower bulk density is another benefit (lower weight and transportation cost). In the lower specific price all benefits of the HSM add up.

The German SME will support through the exchange of information and experience, the introduction of agreed validation procedures for the recognition of skills and scientific cooperation in order, where appropriate, to assess qualitative / quantitative information.

Technical assistance is provided in research projects, for licensees, manufacturers and other commercial customers, but not for end users.

The desired results of cooperation with others (companies, research organisations) are licenses granted to international partners willing to manufacture the HSM (also under their own brand) and partnerships in joint research projects.

The technical and research cooperation agreements are based hourly at cost price. In research projects, the company offers standard cooperation agreements in the role of a subcontractor, that is, as a third party, generally in a subcontracting relationship.

Manufacturing agreements (under license) are freely negotiable.

Advantages and Innovations

The company rethought approaches to optimize traditional chamotte/ceramic based storage materials and found a material (the HSM) that: 
• has a 30-50% higher heat capacity with an adequate heat conductivity, thereby allowing an efficient absorption and storage of the heat at a lower price than other comparable materials (chamotte, ceramics)
• can be sustainably made of natural, hazard-free raw materials without a high temperature process
• allows flexible shapes and very small to very big sizes and is usable for a wide range of applications
• is nevertheless easy and 30% cheaper to produce than competitive solutions
• reduces CO2, soot and particulate matter emissions by about 70% when used in built-in components in wood stoves - contributing to the goals set in the 7th Environment Action Programme of the EU.
• the HSM is an innovative heat storage material for residential heat storage applications (classified with TRL 6 - 9).

Chamotte, feolite and soapstone are currently the standard heat storage materials used in wood stoves and other systems. All three materials have a poor heat capacity, making them quite a bad choice for heat storage materials - see Quantitative data:

Material Chamotte HSM
Specific heat capacity [J/(g∙K)] 0,70 1,40
Heat conductivity [W/(m•K)] 0,50 1,40
Bulk density [g/m3] 2000 1800
CO2 footprint [g/kg] 1000 300
Specific price EUR/(kJ•K)] 1,43 0,49

Depending on their raw material source, soapstone and feolite can contain critical substances like asbestos and chromium (Chrom(VI)-oxide). These cannot only affect the health of the heat storage users but are also critical during the production or disposal of the respective materials.

Stage Of Development

Already on the market

Stage Of Development Comment

The material should now be tested e.g. in the fields of electrical (radiators) and solar thermal storage.

Requested partner

- Research organisations or companies for cooperation in research projects: In research projects, the German SME can offer standard cooperation agreements in the role of a subcontractor, i.e. as a third party. The role of the cooperation partner sought should be clearly defined as the originator, initiator and leader of the project.  

- Companies for technical cooperation

- Companies for manufacturing agreements (under license): freely negotiable.

- Companies interested in licensing the material for their own purposes, also under their own brands: The role of these licensed partners is to manufacture the material and use it in their own products (e.g. stoves and other heat storing systems in general).

Long-term commitments are provided with hands-on organization based on email/phone communication and face-to-face meetings when needed.
Desired partners in the field of heat storage solutions are companies (crafts, industry, science) in Germany, Austria, Switzerland, Denmark and the Netherlands.

Dissemination Countries

Austria, Switzerland, Germany, Denmark, Ireland, Iceland, Malta, Netherlands, Sweden

Contact Profile Owner