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Testing of Encapsulated Thermal Energy Storage for Concentrated Solar Power

Company Name: Terrafore, LLC
Program Office: Solar
Location: Minneapolis, MN
Email: Anoop Mathur, Founder & CTO;
Award Amount: $170,000
Project Term: 11 months
Project Status: Active
Participating Lab(s): Argonne National Laboratory


A recent focus of research into concentrated solar power is the use of high-temperature power cycles, such as those using supercritical carbon dioxide, for high thermal-to-electric conversion efficiencies. These high-temperature power cycles need to be integrated with high-temperature thermal energy storage technologies, operating at temperatures above 700°C. One potential solution is Terrafore's Encapsulated Phase Change Materials Thermal Energy Storage (EPCM-TES) technology, featuring a high-temperature phase-change salt that melts above 700°C.

Terrafore does not have the capability and expertise to demonstrate the EPCM-TES technology at temperatures over 700°C, but Argonne National Laboratory (ANL) does. ANL has developed and installed a unique test capability for performance testing of thermal energy storage systems at temperatures over 700°C. In addition, ANL researchers have the expertise and ability to conduct modeling and thermal characterizations of materials and systems.

In this SBV Pilot, the reliability, longevity, and thermal stability of Terrafore's coated salt capsules — which are used to store thermal energy for concentrating solar power plants — will be demonstrated. If successful, this project will deliver a novel EPCM-TES solution for solar and other processes in the heat recovery and storage markets.


Terrafore is developing high-temperature coatings to enable its phase-change material capsules to contain molten PCM salt during charging and discharging in the emerging concentrated solar power sector. This involves identifying and applying the coating material to the capsules, followed by durability and performance testing at temperatures between 650 and 750°C.


To date, Terrafore has demonstrated EPCM-TES technology for low temperature storage applications at temperatures under 400°C. The work at ANL will enable Terrafore to elevate its EPCM-TES technology platform to significantly higher temperatures. Based on the performance data, a techno-economic analysis of the EPCM technology will be conducted to identify integration pathways with CSP plants and other technology areas. 

This will open new market and business opportunities for Terrafore, notably in concentrated solar power, furthering the expansion of solar energy in the U.S. Testing could also lead to new opportunities for Terrafore to expand into a host of other process industries.

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