U.S. Department of Energy  Energy Efficiency and Renewable Energy
SunShot Initiative
Novel Thermal Energy Storage Systems for Concentrating Solar Power
Latent heat thermal energy storage system with embedded heat pipes to reduce thermal resistance.
The University of Connecticut, under the Thermal Storage FOA, is developing innovative heat transfer devices and methodologies for novel thermal energy storage (TES) systems for CSP involving phase change materials (PCMs).
Approach
Specific objectives include embedding thermosyphons and/or heat pipes (TS/HPs) within appropriate PCMs to significantly reduce thermal resistances within the TES system of a largescale CSP plant and, in turn, improve performance of the plant. The expected outcome of the research is generation of the necessary fundamental knowledge to enable fullscale design of a system that reduces the LCOE and increases roundtrip efficiency of CSP. Manufacture of the proposed heat transfer devices presents a novel opportunity for economic development.
Innovation
This work utilizes embedded thermosyphons or heat pipes in the PCM to reduce the thermal resistance between the location where phase change occurs and the working fluid of the power cycle. Either thermosyphons or heat pipes can:
 Provide an effective thermal conductivity that is up to 90 times that of copper
 Transfer large amounts of energy nearly isothermally
 Be customtailored for performance by carefully selecting the TS/HP working fluid and its operating pressure, as well as the wall material
 Be fabricated in a wide variety of shapes.
The intended outcome of this research is the development of a PCM storage system with the capability of achieving an energy cost of $15/kWth. This work aims to prove or disprove the ability of heat pipes to enhance heat transfer in PCM TES systems.
Publications, Patents, and Awards
 S. Wang, A. Faghri, and T.L. Bergman, "A Comprehensive Numerical Model for the Melting With Natural Convection," International Journal of Heat and Mass Transfer, Vol. 53, Nos. 910, pp. 19862000, 2010.
 H. Shabgard, T.L. Bergman, N. Sharifi, and A. Faghri, "High Temperature Heat Pipe Thermal Energy Storage," International Journal of Heat and Mass Transfer, Vol. 53, Nos. 1516, pp. 29792988, 2010.
 S. Wang, A. Faghri, and T.L. Bergman, "Numerical Modeling of Alternative Melting and Solidification," Numerical Heat Transfer, Part B Vol. 58, No. 6, pp. 393418, 2010.
 C.W. Robak, T.L. Bergman, and A. Faghri, "Enhancement of Latent Heat Energy Storage Using Embedded Heat Pipes," International Journal of Heat and Mass Transfer, Vol. 54, Nos. 1516, pp. 34763484, 2011.
 M. Aghvami and A. Faghri, "Analysis of Flat Heat Pipes with Various Heating and Cooling Configurations," Applied Thermal Engineering, Vol. 31, Nos. 1415, pp. 26452655, 2011.
 C.W. Robak, T.L. Bergman, and A. Faghri, "Economic Evaluation of Latent Heat Thermal Energy Storage Using Embedded Thermosyphons for Concentrating Solar Power Applications," Solar Energy, Vol. 85, No. 10, pp. 24612473, 2011.
 N. Sharifi, T.L. Bergman, and A. Faghri, "Enhancement of PCM Melting in Enclosures With HorizontallyFinned Internal Surfaces," International Journal of Heat and Mass Transfer, Vol. 54, Nos. 1920, pp. 41824192, 2011.
 H. Shabgard and A. Faghri, "Performance Characteristics of Cylindrical Heat Pipes With Multiple Heat Sources," Applied Thermal Engineering, Vol. 31, No. 16, pp. 34103419, 2011.
 H. Shabgard, C.W. Robak, T.L. Bergman, and A. Faghri, "Heat Transfer and Exergy Analysis of Cascaded Latent Heat Thermal Energy Storage With GravityAssisted Heat Pipes for Concentrating Solar Power Applications," Solar Energy, Vol. 86, No. 3, pp. 816830, 2012.
 N. Sharifi, S. Wang, T.L. Bergman, and A. Faghri, "Heat PipeAssisted Melting of a Phase Change Material," International Journal of Heat and Mass Transfer, Vol. 55, Nos. 1314, pp. 3458–3469, 2012.
 K. Nithyanandam and R. Pitchumani, "Analysis and Design of DyeSensitized Solar Cell," Solar Energy, Vol. 86, No. 1, pp. 351368, 2012.
 K. Nithyanandam and R. Pitchumani, "Analysis and Optimization of a Latent Thermal Energy Storage System With Embedded Heat Pipes," International Journal of Heat and Mass Transfer, Vol. 54, Nos. 2122, pp. 45964610, 2011.
 K. Nithyanandam and R. Pitchumani, "Computational Modeling of Dynamic Response of a Latent Thermal Energy Storage System With Embedded Heat Pipes," Paper ES201154501, in Proceedings of the 5th International Conference on Energy Sustainability; Washington, DC, August 710, 2011, pp. 753762, ISBN: 9780791854686.
 K. Nithyanandam and R. Pitchumani, "Computational Modeling of Latent Heat Thermal Energy Storage System With Integral Heat Pipes," Paper IMECE201038682, in Proceedings of the ASME International Mechanical Engineering Congress and Exposition, Vancouver, BC, November 1218, 2010, pp. 369376, ISBN: 9780791844298.
 K. Nithyanandam and R. Pitchumani, "Analysis and Design of DyeSensitized Solar Cells," Paper IHTC1423101, in Proceedings of the 14th International Heat Transfer Conference, Washington, DC, August 813, 2010, pp. 565572, ISBN: 9780791849422.
Quarterly Progress Reports
Learn about other DOE competitive awards for concentrating solar power research that are in progress.
