Programm Photovoltaik Ausgabe 2008 ... - Bundesamt für Energie BFE

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National and international collaboration
In the framework of the sub-project « Molecular Based Concepts », where ECN (Petten, NL) is the
sub-project leader, collaboration is essentially with Imperial College of Science, Medicine and
Technology (London, UK) regarding the special Si-solar cell supply, the Fraunhofer-Institut fuer
Angewandte Polymerforschung (Golm, DE) provides the PMMA-polymer based flat plate concentrator
sheets in sizes up to 10x10 cm (ca 3 to 5 mm thick), the University of Utrecht (Utrecht, NL) provides
the quantum dots & new dyes to the partners and RWE-SSP (Heidelberg, DE) provided the multijunction
solar cells to be built on the edges of the flat-plate concentrators.
National collaboration: as an alternative to the cut-out Si-cells, we are investigating the use of Dye Solar
Cells such as the ones developed by Prof M. Graetzel at the EPFL (Lausanne) and Solaronix. Dye
Solar Cells have the advantage of delivering a higher voltage than the Si-cells and they can be tailored
to the emission spectrum of the fluorecent dye employed in the Flat Plate Concentrator.
Evaluation 2007 and Outlook 2008
The stability of the dye CRS040 in 470 nm LED light was insufficient when measured in solution, confirming
the degradation observed earlier in flat plate concentrators exposed to 470 nm LED light.
For future works, a new yellow dye needs to be found, candidates are L.F. Yellow 170 and L.F. Yellow
083 made by Thomas Swan (U.K.).
Interestingly, the electrical output from certain flat plate concentrators having a Si-cell attached on one
side stayed quite constant when irradiated over 700 hours by the 470 nm high intensity LED light
(drop between 4 and 12 %).
Thanks to the work of the FhG-IAP (A. Büchtemann), the quality of the PMMA matrix was considerably
improved by changing the polymerization and curing procedures, affording a bubble-free material,
having also a lower absorption in the visible spectrum.
For future works (WP4.1), an optimized dye solar cell colored with PCH-001 will be made, this cell will
be mounted on the edge of a red luminescent flat plate concentrator, and the system efficiency will be
analysed. New dyes from the University Utrecht (S. Wadke) will also be investigated in test dye solar
cells
In WP4.3, long duration (>1000 hours) stability tests to prove a 3-5 years outdoors equivalent stability
of practical flat plate concentrators will be made using the “Plasma-sulfur” that we developed, having a
light output resembling closely the solar spectrum (class B simulator).
Solaronix is also in charge of the stability review report, summarizing all the data obtained so far on
the flat plate concentrator durability tests.
The expected cost calculation for WP4.1 will be computed once a geometry and possible product(s)
are identified. Flat plate concentrators might be used in consumer goods to form a “light harvesting
antenna” to generate electricity to charge mobile electronics. Such a device might by aesthetically appealing,
as it is semitransparent and not looking like classical photovoltaic solar cells.
References
[1] A. Luque, A. Marti, A. Bett, V.M. Andreev, C. Jaussaud, J.A.M. van Roosmalen, J. Alonso, A. Räuber, G. Strobl, W. Stolz,
C. Algora, B. Bitnar, A. Gombert, C. Stanley, P. Wahnon, J.C. Conesa, W.G.J.H.M. van Sark, A. Meijerink, G.P.M. van
Klink, K. Barnham, R. Danz, T. Meyer, I. Luque-Heredia, R. Kenny, C. Christofides, G. Sala, P Benitez "FULLSPEC-
TRUM: a new PV wave making more efficient use of the solar spectrum" Solar Energy Materials & Solar Cells 87
(2005) 467-479.
[2] L.H.Slooff, R.Kinderman, A.R.Burgers, J.A.M. van Roosmalen, A.Büchtemann, R.Danz, T.B. Meyer, A.J. Chatten,
D.Farrell, K.W.J.Barnham "The luminescent concentrator Illuminated" Conf. proc. of Photonics Europe, Strasbourg,
April 2006.
[3] A. Burgers, L.Slooff, A.Büchtemann, J.A.M.van Roosmalen "Performance of single layer luminescent concentrators
with multiple dyes" Procs. of the 4th World Conference on Photovoltaic Energy Conversion, Hawaii, May 2006.
FULLSPECTRUM, T. Meyer, Solaronix
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