uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Solution-Chemically Derived Spectrally Selective Solar Absorbers: With System Perspectives on Solar Heating
Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Technology, Department of Engineering Sciences.
2006 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis consists of two parts, one dominating part concerning spectrally selective solar absorbers and one dealing with thermal solar systems. The appended papers I to VIII concern the solar absorber part, papers dealing with the systems part have not been included in the thesis.

A new spectrally selective absorber derived from a novel solution-chemistry method has been developed and optimized. The main objective was to investigate the potential of the spectrally selective surface. Some of the questions at issue were; would it be possible to create a suitable absorber composite using this method, how high selectivity could be obtained, could the performance be enhanced by using anti-reflection coatings, which was the optimal layer composition, would the thin films be durable and what was the structure and morphology like on a nano scale? The absorber consists of absorbing thin films of nickel nano-particles embedded in a dielectric matrix of alumina and an overlying anti-reflection film consisting of one of the following materials silica, hybrid-silica, alumina or silica-titania. Solution and sol-gel chemistry were used in the process. The thin films were spin-coated onto an aluminum substrate followed by a heat-treatment that generated the multi layer selective solar absorber.

The optical constants for the thin film materials in question were determined. An optimal three layer structure was modeled using the experimentally determined optical constants. The theoretical three layer stack was experimentally confirmed and achieved a solar absorptance of 0.97 and a thermal emittance of 0.05 which definitely are commercially competitive values. The configuration of the three layer stack is: an 80%nickel-20%alumina film at the base, a 40%nickel-60%alumina film in the middle and a silica or hybrid-silica film at the top. The three layer absorber was subjected to high temperature and condensation accelerated ageing tests designed by IEA Task 27. The condensation test did not degrade the absorber whatsoever but the high temperature test did reveal some oxidation of the nickel particles. The oxidation occurs initially and then stops. A formed nickel-oxide layer hinders further oxidation. The level of oxidation is small and the absorber is qualified according to the IEA Task 27 test procedure.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis , 2006. , p. 91
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 225
Keywords [en]
Materials science, solar, thermal, absorber, selective, chemical
Keywords [sv]
Materialvetenskap
Identifiers
URN: urn:nbn:se:uu:diva-7160ISBN: 91-554-6663-X (print)OAI: oai:DiVA.org:uu-7160DiVA, id: diva2:168922
Public defence
2006-10-20, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 10:00
Opponent
Supervisors
Available from: 2006-09-29 Created: 2006-09-29Bibliographically approved
List of papers
1. Solution-chemical derived nickel–alumina coatings for thermal solar absorbers
Open this publication in new window or tab >>Solution-chemical derived nickel–alumina coatings for thermal solar absorbers
2003 In: Solar Energy, ISSN 0038-092, Vol. 74, p. 497-503Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-94897 (URN)
Available from: 2006-09-29 Created: 2006-09-29Bibliographically approved
2. Anti-reflection coatings for solution-chemically derived nickel-alumina solar absorbers
Open this publication in new window or tab >>Anti-reflection coatings for solution-chemically derived nickel-alumina solar absorbers
2004 In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, Vol. 84, p. 183-191Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-94898 (URN)
Available from: 2006-09-29 Created: 2006-09-29Bibliographically approved
3. Optimization of a solution-chemically derived solar absorbing spectrally selective surface
Open this publication in new window or tab >>Optimization of a solution-chemically derived solar absorbing spectrally selective surface
2007 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 91, no 1, p. 38-43Article in journal (Refereed) Published
Abstract [en]

A previously studied solution chemically derived two layer absorber has been improved by adding a third layer. Simulations done with a thin film program showed that the optimized three layer selective absorber should be composed of an 80% nickel-20% alumina film of 100 nm at the base, a 40% nickel-60% alumina film of 60 nm in the middle and finally a 100% silica film of 85 nm at the top. Experimental results confirmed the computer simulated three layer structure. Prepared absorber consisting of the theoretically found optimized layer structure achieved a solar absorptance, alpha(sol), of 0.97 and a thermal emittance, epsilon(therm), of 0.05.

Keywords
Spectrally, Selective, Solution, Absorber, Thermal
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-94899 (URN)10.1016/j.solmat.2006.07.002 (DOI)000242282400005 ()
Available from: 2006-09-29 Created: 2006-09-29 Last updated: 2017-12-14Bibliographically approved
4. Optical properties of solution-chemically derived thin film Ni-Al2O3 composites and Si, Al, and Si-Ti oxides
Open this publication in new window or tab >>Optical properties of solution-chemically derived thin film Ni-Al2O3 composites and Si, Al, and Si-Ti oxides
2006 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, Vol. 18, p. 7737-7750Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-94900 (URN)
Available from: 2006-09-29 Created: 2006-09-29 Last updated: 2016-06-22Bibliographically approved
5. Characterizing a Ni-Al2O3/SiO2 solar thermal absorber
Open this publication in new window or tab >>Characterizing a Ni-Al2O3/SiO2 solar thermal absorber
Show others...
In: Thin Solid FIlms, ISSN 0040-6090Article in journal (Refereed) Submitted
Identifiers
urn:nbn:se:uu:diva-94901 (URN)
Available from: 2006-09-29 Created: 2006-09-29Bibliographically approved
6. ERDA of Ni-Al2O3/SiO2 solar thermal selective absorbers
Open this publication in new window or tab >>ERDA of Ni-Al2O3/SiO2 solar thermal selective absorbers
Show others...
2008 (English)In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, E-ISSN 1879-3398, Vol. 92, no 10, p. 1177-1182Article in journal (Refereed) Published
Abstract [en]

Thin film materials for the use in solar thermal absorbers have been investigated using time-of-flight energy elastic recoil detection analysis (ERDA). The ERDA measurements proved to be very efficient in detecting the elemental depth composition of a selective solar absorber. The three-layer absorber is composed of an 80% nickel-20% alumina film at the base, a 40% nickel-60% alumina layer in the middle and finally an AR film of silica or hybrid-silica film at the top. The difference between solution volume percent and actual volume percent could be investigated when studying individual nickel-alumina films with varying ratios coated on glass substrates. The result showed that there was a maximum difference of 3% between the calculated solution volume percent and the actual volume percentages in the solid films. The ERDA measurements also indicate that about 15% of the nickel found in the nickel-alumina composite films is bound in the form of NiO.

Keywords
solar, absorber, selective, SEM, ToF-ERDA
National Category
Engineering and Technology Subatomic Physics
Research subject
Ion Physics
Identifiers
urn:nbn:se:uu:diva-94902 (URN)10.1016/j.solmat.2008.02.014 (DOI)000258431300001 ()
Available from: 2006-09-29 Created: 2006-09-29 Last updated: 2018-12-10Bibliographically approved
7. Durability tests of solution-chemically derived spectrally selective absorbers
Open this publication in new window or tab >>Durability tests of solution-chemically derived spectrally selective absorbers
2005 In: Solar Energy Materials and Solar Cells, ISSN 0927-0248, Vol. 89, p. 197-207Article in journal (Refereed) Published
Identifiers
urn:nbn:se:uu:diva-94903 (URN)
Available from: 2006-09-29 Created: 2006-09-29Bibliographically approved
8. Accelerated ageing tests of optimized solution-chemically derived selective solar thermal absorbers
Open this publication in new window or tab >>Accelerated ageing tests of optimized solution-chemically derived selective solar thermal absorbers
2006 (English)In: Proceedings of Eurosun 2006Article in journal (Refereed) Published
National Category
Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-94904 (URN)
Available from: 2006-09-29 Created: 2006-09-29 Last updated: 2016-06-22Bibliographically approved

Open Access in DiVA

fulltext(1629 kB)3095 downloads
File information
File name FULLTEXT01.pdfFile size 1629 kBChecksum SHA-1
9e6e57f54c2d38118fddea50f4e9be33f1c2eda92e82b452070969db51bad421bee292b3
Type fulltextMimetype application/pdf
cover(162 kB)60 downloads
File information
File name COVER01.pdfFile size 162 kBChecksum SHA-1
2bf4843904a6eb172bf13909fa1d6b7ae098092ae6fb17a96b7b8e65d6f916c59f573aa1
Type coverMimetype application/pdf
Buy this publication >>

By organisation
Department of Engineering Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 3095 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 3641 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf