Carbon materials for solar thermal energy

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dc.contributor.upauthor Badenhorst, Heinrich
dc.date.accessioned 2015-08-25T08:18:30Z
dc.date.available 2015-08-25T08:18:30Z
dc.date.issued 2015
dc.description.abstract Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015. en_ZA
dc.description.abstract Cost-effective capture and storage of solar energy still remains a challenge facing broad-based implementation of this renewable technology. Work at the South African Research Chairs Initiatives (SARChI), Chair in Carbon Materials and Technology at the University of Pretoria is aimed at developing materials from cheap, local carbon sources for solar thermal applications. The focus is split on developing composites for both solar energy capture and thermal energy storage. Preliminary investigations are based on systems designed to provide heating needs like hot water through solar energy. Two different approaches to the capture of solar energy were explored. Firstly the use of carbon black and expanded graphite pressed discs and secondly the production of mesophase based graphitic foams. The carbon black discs demonstrated the ability to reach a peak collector temperature of around 70 °C whilst providing approximately 4 kW.hr per m2 per day. The foam with the best capture had an efficiency calculated at around 95%. This is based on measured incoming radiation converted into sensible heating of the water. Phase change materials present an efficient and innovative solution to the problem of thermal energy storage. These materials suffer from a major drawback due to their low thermal conductivity. Two alternatives were explored for enhancing this property. Firstly the direct incorporation of phase change material into expanded graphite was tested. A variety of loadings were explored. It was found that at low concentrations of 6 mass % the time required for the sample to undergo the phase transition could be reduced by 70% for heating and 85% for cooling. Beyond this point the decrease in phase transition time diminishes. Ongoing work is also being done to explore the use of highly conductive sheets manufactured from roller-pressed expanded graphite. Unfortunately these sheets suffer from structural integrity issues which are being optimized. en_ZA
dc.description.librarian dc2015 en_ZA
dc.format.extent 6 pages en_ZA
dc.format.medium PDF en_ZA
dc.identifier.citation Badenhorst, H. 2015, 'Carbon materials for solar thermal energy', Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015. en_ZA
dc.identifier.uri http://hdl.handle.net/2263/49523
dc.language.iso en en_ZA
dc.publisher 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015. en_ZA
dc.rights © 2015 University of Pretoria en_ZA
dc.subject Solar energy en_ZA
dc.subject Renewable technology en_ZA
dc.subject Thermal energy storage en_ZA
dc.subject Carbon black and expanded graphite pressed discs en_ZA
dc.subject Production of mesophase based graphitic foams en_ZA
dc.title Carbon materials for solar thermal energy en_ZA
dc.type Presentation en_ZA


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