Nanosolar: Photovoltaic Hindsight Insights? REVISED

Reviewing the efficiency calculation.

Building on my prior post, Nanosolar: Photovoltaic Hindsight Insights?, “Nanosolar to Build 10MW Power Plant” by Ucilia Wang at Greentech Media obtained feedback on the story from Nanosolar, Inc. Chief Executive Officer Martin Roscheisen:

Roscheisen also wrote that two technical details in the newspaper articles were wrong. The June article said the size of the glass plate for a finished panel measures at 2 square meters. Roscheisen wrote that Nanosolar's panel is "compatible with First Solar's, which are 1.6 x .8m in size."

Roscheisen added that the 7,000 panels reported for the 1-megawatt plant also was wrong, but didn't offer the correct number.

Well, Nanosolar partner Beck Energy GmbH has First Solar’s FS Series 2 Solar Module datasheet (Deutsch) on their website, and the First Solar module dimensions are in fact 1.2 x 0.6m (meters).

Looking at the Nanosolar module array photo shown in Nanosolar solar modules shipping!, the modules are arranged as five (5) by ten (10) CIGS (copper indium gallium diselenide) rectangular looking solar cells. I do not believe Nanosolar has ever stated the cell size; they appear to be about 6” (156mm) square in area terms? This rough sizing would confirm the 1.6 x 0.8m panel size.

Using the 1.6 x 0.8m panel size cited by Mr. Roscheisen and the calculated 142.9 Watts per module assuming the 7000 panels remains reasonable, the implied Nanosolar Utility Panel module efficiency becomes 11.16%.

First, do I need to point out the 142.9 Watts per module would be an average module efficiency for the entire 1 MWp (MegaWatt-peak) installation? Per Sorted-Cell Assembly, Nanosolar’s metal foil substrate cells can be tested, binned, and matched to increase module efficiency and yield much like crystalline silicon based solar cells. No doubt the unpublic Nanosolar Utility Panel module datasheet includes a range of power ratings. However, without Nanosolar cell or module production efficiency data in histogram form, it is impossible to determine if more or less than 7000 modules are required for the 1 MWp Luckenwalde landfill project as Mr. Roscheisen asserts. For example, if the average module efficiency is 12% (153.6 Wp, Watt-peak), about 6500 modules would be required for the 1MWp installation, while 10% average module efficiency (128 Wp) would require just over 7800 modules.

From the Nanosolar Wikipedia entry, I found this award winning article, “Solarzellen - einfach gedruckt” (“Solar cells – simply printed”, German only) by Johannes Bernreuter for bild der wissenschaft 2|2007, also referenced by the Nanosolar website. The article delves into the history of the nanoparticle CIGS printing technology and past efficiency, potential, and verified efficiency results. Please remember the “14.5% Cell Produced Using Low-Cost Printing Process” touted by Nanosolar was for a 0.47 square centimeter cell printed on a glass substrate. NREL (National Renewable Energy Laboratory) measured the cell’s efficiency at 13.95% in August 2006, and Nanosolar said:

NREL measured one of Nanosolar’s cells on glass at about 14% on a total-area basis, equivalent to about 14.5% on an active-area basis after correcting for shadowing by the grid (Voc = 599mV, Jsc = 32.2mA/cm2, FF = 72.3).

To our knowledge, this is the highest efficiency yet reported for any printed solar cell of any kind and any CIGS cells fabricated using non-vacuum methods in particular.

in the PVSEC-17 paper, “HIGH-PERFORMANCE THIN-FILM PHOTOVOLTAICS USING LOW-COST PROCESS TECHNOLOGY”.

I hesitate to share this. One of my favorite German restaurants near Luckenwalde, Landgasthof "Zum Märkischen Eck", is about a 20 minute drive from Nanosolar GmbH. It’s worth a visit; just make sure to save a table for my relatives and me!

PVSEC-17 Photovoltaic Conference Resources

"Be Ambitious! Seek the inspiration to bring happiness to humanity through your work in PV."

Since those closing words from the 17th International Photovoltaic Science and Engineering Conference (PVSEC-17) General Chairperson Professor Masafumi Yamaguchi (Toyota Technological Institute), the information packed Closing Address and Opening Address presentations have been uploaded to the PVSEC-17 Program page.

1439 Conference participants from around the world converged on the Fukuoka International Congress Center in Fukuoka, Japan, from December 3-7, 2007, for the 17th International Photovoltaic Science and Engineering Conference (PVSEC-17). The PVSEC-17 Conference was dominated by Japan with 769 participants while the top six (6) was rounded out by Korea 182, Taiwan 123, USA 95, Germany 74, and China 22. The simultaneous PVSEC-17 Exhibition featuring 46 Exhibitors attracted 5027 visitors over the course of 3 days.

During the PVSEC-17 Conference, 627 Papers from 36 countries were presented including about 364 Poster Presentations. Germany vaulted to third in Papers from their participant attendance rank of fifth. Chairperson Professor Yamaguchi noted the above trend ratio of Papers to Attendees for PVSEC-17 versus peer international photovoltaic conferences: EU PVSEC, IEEE-PVSC, and WCPEC.

First, here is an outline of the PVSEC-17 Conference Program by topic Area:
Area 1 Novel Materials and Devices
Area 2 III-V Materials and Devices for Concentrator and Space PV Systems
Area 3 Crystalline Silicon Solar Cells and Technologies
Area 4 Amorphous & Nano/Microcrystalline Silicon Based Solar Cells and Related Materials
Area 5 CIGS, II-VI and Related Thin Films and Cells
Area 6 PV Modules and System Components
Area 7 Terrestrial PV Systems
Area 8 PV Programs, Industries, Market, and Environment

Here are the links to Oral Sessions segmented by Conference day: December 3, December 4, December 5, December 6, and December 7.

Here are the Poster Sessions with focus topic Area(s):
Poster Session 1 Area 3, Area 7
Poster Session 2 Area 3
Poster Session 3 Area 5, Area 8
Poster Session 4 Area 2, Area 6
Poster Session 5 Area 1, Area 4
Poster Session 6 Area 1, Area 4

The Closing Address presentation includes:

Program Summary
Program Highlights
Awards Commendation Ceremony

Readers are directed to review the selected Program Highlights for themselves (Closing Address, pp. 7-15).

Below, I have included the Paper, Poster, and Young Researcher Award winners. Please note a number of Areas have co-winners.

Paper Awards

Area 1
4O-A3-02 SCANNING PROBE MICROSCOPE STUDY OF DYE-SENSITIZED TiO2(110)
A. Sasahara^1,2, M. Ikeda¹, N. Koide³, L. Han³ and H. Onishi^1
1Kobe University, Japan, ²Japan Science and Technology Agency, Japan, ³Sharp Corporation, Japan

Area 2
6O-B11-03 DEVELOPMENT OF SPACE SOLAR SHEET
T. Kodama¹, H. Yamaguchi¹, N. Takahashi¹, T. Agui¹, H. Washio¹, K. Nakamura¹, T. Hisamatsu¹,
T. Takamoto¹, K. Shimazaki², M. Imaizumi² and K. Kibe^2
1SHARP Corporation, Japan, ²Japan Aerospace Exploration Agency, Japan

Area 3
6O-M5-01 HIGH EFFICIENCY MULTICRYSTALLINBE SILICON BACK CONTACT SOLAR CELLS
N. Nakatani, T. Sakamoto, K. Fukui and K. Shirasawa
Kyocera Corporation, Japan

6O-M4-01 22%-EFFICIENCY HIT SOLAR CELL
Y. Tsunomura, Y. Yoshimine, M. Taguchi, T. Kinoshita, H. Kanno, H. Sakata, E. Maruyama and M. Tanaka
SANYO Electric Co., Ltd., Japan

Area 4
5O-B6-01 LIGHT SCATTERING EFFECTS OF HIGHLY TEXTURED TRANSPARENT CONDUCTIVE OXIDES FILMES
N. Taneda, M. Kambe, T. Oyama and K. Sato
Asahi Glass Co., Ltd., Japan

5O-B7-02 THIN FILM SOLAR CELLS BASED ON MICROCRYSTALLINE SILICON-GERMANIUM NARROW GAP ABSORBERS
T. Matsui¹, C.W. Chang¹, T. Takada^1,2, M. Isomura², H. Fujiwara¹ and M. Kondo^1
1National Institute of Advanced Industrial Science and Technology (AIST), Japan, ²Tokai University, Japan

Area 5
6O-A11-02 MASS-PRODUCTION TECHNOLOGY FOR CIGS MODULES
K. Matsunaga¹, T. Komaru¹, Y. Nakayama¹, T. Kume², and Y. Suzuki^2
1Honda Engineering Co., Ltd., Japan, ²Honda Soltec Co., Ltd., Japan

Area 6
6O-A10-02 DIFFERENCE IN THE OUTDOOR PERFORMANCES OF BULK AND THINFILM SILICON BASED PHOTOVOLTAIC MODULES
T. Minemoto, S. Fukushige and H. Takakura
Ritsumeikan University, Japan

Area 7
5O-C8-01 PERFORMANCE OF GRID CONNECTED PV INVERTERS DURING DISTURBED GRID CONDITIONS - CURRENT STATE OF PLAY & RECOMMENDATIONS FOR OPTIMAL PRODUCT DESIGN
R. Bruendlinger, B. Bletterie and C. Mayr
arsenal research, Austria

Area 8
6O-C9-05 ENVIRONMENTAL POTENTIAL OF VERY LARGE SCALE PHOTOVOLTAIC POWER GENERATION (VLS-PV) SYSTEMS ON DESERTS
K. Komoto¹, M. Ito², N. Yamashita³ and K. Kurokawa^3
1Mizuho Information & Research Institute, Inc., Japan, ²Tokyo Institute of Technology, Japan, ³Tokyo University of Agriculture and Technology, Japan

Poster Awards

Area 1
6P-P6-35 STRUCTURAL AND OPTICAL PROPERTIES OF PHOSPHORUS DOPED SILICON QUANTUM DOT SUPPERLATTICE FOR ALL SILICON TANDEM SOLAR CELL
X. Hao¹, E. Cho¹, G. Scardera¹, E. Bellet², D. Bellet², S. Park³, G. Conibeer¹ and M. A. Green^1
1University of New South Wales, Australia, ²Laboratoire GPM2-ENSPG, France, ³Samsung Advanced Institute of Technology, Korea

6P-P6-28 USE OF ZNO NANOSTRUCTURE TOWARDS HIGH EFFICIENCY INORGANIC/ORGANIC HYBRID THIN FILM SOLAR CELLS
K. Takanezawa, K. Tajima and K. Hashimoto
The University of Tokyo, Japan

Area 2
5P-P4-14 FIELD TEST OF A GRID-CONNECTED 500X CONCENTRATOR PV SYSTEM WITH DOME FRESNEL LENS
Y. Kemmoku¹, K. Araki², Y. Miyazaki³ and M. Hiramatsu^3
1Toyohashi Sozo University, Japan, ²Daido Steel Co., Ltd., Japan, ³Daido Metal Co., Ltd., Japan

Area 3
4P-P1-23 REAL-TIME OBSERVATION OF UNIDIRECTIONAL SOLIDIFICATION PROCESSES FOR HIGHER-QUALITY MULTICRYSTALLINE SILICON INGOTS
I. Yamaga, K. Yamada, N. Araki, H. Suzuki and T. Saitoh
Dai-Ichi Kiden Corp., Japan

4P-P2-33 ALTERNATIVES TO SCREEN PRINTING FOR THE FRONT SIDE METALLIZATION OF SILICON SOLAR CELLS
M. Alemán, N. Bay, A. Knorz, A. Grohe and S. W. Glunz
Fraunhofer Institute for Solar Energy Systems, Germany

Area 4
6P-P6-62 ELECTRICAL AND OPTICAL PROPERTIES OF HYDROGEN-TREATED ZnO:Al FILMS
S. Tark¹, M. Kang¹, S. Lee², W. Kim² and D. Kim^1
1Korea University, Korea, ²Korea Institute of Science and Technology, Korea

Area 5
5P-P3-13 SOLVOTHERMAL SYNTHESIS OF COPPER INDIUM DISELENIDE WITH FACILE SOLUTION ROUTE
J. Chang, H. Nam, J. Han and D. Jung
Sungkyunkwan University, Korea

5P-P3-17 BIFACIAL CIGS THIN FILM SOLAR CELLS USING HIGH MOBILITY Ti-DOPED In2O3 BACK CONTACTS
T. Miyano, R. Hashimoto, Y. Kanda, T. Mise and T. Nakada
Aoyama Gakuin University, Japan

Area 6
5P-P4-36 EXPERIMENTAL STUDIES ON DETECTING A DISCONNECTION POSITION OF BETWEEN PV MODULES BY THE ELECTRIC CAPACITANCE MEASUREMENT
J. Yamaguchi¹, T. Takashima² and M. Ishida^1
1University of Tsukuba, Japan, ²AIST, Japan

Area 7
4P-P1-48 RESEARCH ON THREE-DIMENSIONAL COORDINATES ACQUISITION FOR SHADOW ESTIMATION IN PHOTOVOLTAIC SYSTEM
Y. Watanabe and K. Krokawa
Tokyo University of Agriculture and Technology (TUAT), Japan

Area 8
5P-P3-76 FINANCING A VERY LARGE SCALE PHOTOVOLTAIC SYSTEM IN GOBI DESERT
K. Megherbi¹, M. Ito², F. D. Ferretti¹ and K. Kurokawa^3
1Dexia Credit Local, France, ²Tokyo Institute of Technology, Japan, ³Tokyo University of Agriculture and Technology, Japan

Young Researcher Awards

Area 1
5O-A6-03 ORGANIC THIN–FILM SOLAR CELL EMPLOYING A NOVEL ELECTRON-DONOR MATERIAL
H. Kanno, M. Shirakawa, D. Fujishima, T. Kinoshita, H. Sakata, E. Maruyama and M. Tanaka
Sanyo Electric Co., Ltd., Japan

Area 2
6O-B11-06 ANALYSIS OF SOLAR CELL DEGRADATION MECHANISM DUE TO ESD IN SPACE
T. Okumura¹, K. Toyoda¹, M. Imaizumi² and M. Cho^1
1Kyushu Institute of Technology, Japan, ²Japan Aerospace Exploration Agency, Japan

Area 3
4P-P2-15 A NEW METHOD FOR THE PRODUCTION OF ULTRA-THIN CRYSTALLINE SI WAFERS
F. Dross¹, A. Milhe^1,2, J. Robbelein¹, I. Gordon¹,P. O. Bouchard², G. Beaucarne¹ and J. Poortmans^1
1IMEC, v.z.w., Belgium, ²Ecole des Mines de Paris (CEMEF), France

Area 4
5O-B7-04 6.3% EFFICIENCY SOLAR CELL EMPLOYING HIGH DEPOSITION RATE (8 NM/S) MICROCRYSTALLINE SILICON PHOTOVOLTAICLAYER
Y. Sobajima, M. Nishino, T. Fukumori, T. Higuchi, S. Nakano, T. Toyama and H. Okamoto
Osaka University, Japan

Area 5
4O-C4-02 PHYSICAL VAPOUR DEPOSITION OF COMPOUND INDIUM SULPHIDE AS BUFFER LAYER IN CU(IN,GA)SE2 SOLAR CELLS: MATERIAL CHARACTERISATION AND DEVICE PERFORMANCE
P. Pistor¹, R. Caballero¹, D. Hariskos², V. Izquierdo-Roca³, R. Wächter⁴ and R. Klenk^1
1Hahn-Meitner-Institut, Germany, ²Zentrum fuer Sonnenenergie-und Wasserstoff-Forschung, Germany, ³Universitat de Barcelona, Spain, ⁴Würth Solar GmbH & Co. KG, Germany

6O-A11-03 FABRICATION OF PENTANARY Cu(InGa)(SeS)2 ABSORBERS BY SELENIZATION AND SULFURIZATION
Y. Goushi, H. Hakuma, K. Tabuchi, S. Kijima and K. Kushiya
Showa Shell Sekiyu K.K., Japan

Area 6
6O-A10-03 AN LED-BASED PHOTOVOLTAIC MEASUREMENT SYSTEM WITH VARIABLE SPECTRUM AND FLASH SPEED
M. Bliss, T. R. Betts and R. Gottschalg
Loughborough University, UK

Area 7
5O-C6-03 ESTIMATING THE CAPACITY VALUE AND PEAK-SHAVING POTENTIAL OF PHOTOVOLTAICS IN ONTARIO: A CASE-STUDY FOR THE CITY OF TORONTO
S. Pelland¹ and I. Abboud^2
1CANMET Energy Technology Centre-Varennes, Canada, ²Environment Canada Experimental Studies Division ARQX, Canada

5O-C8-02 AN ANALYSIS OF ELECTRICITY COST OF PHOTOVOLTAIC SYSTEMS ON THE FIELD TEST PROJECT IN JAPAN
T. Oozeki¹, T. Yamada¹, K. Kato¹ and T. Yamamoto^2
1National Institute of Advanced Industrial Science and Technology, Japan, ²New Energy and Industrial Technology Development Organization (NEDO), Japan

Area 8
6O-C9-01 A PRELIMINALY LIFE-CYCLE ANALYSIS OF A MEGA-SOLAR SYSTEM IN JAPAN
M. Ito¹, M. Kudo² and K. Kurokawa^3
1Tokyo Institute of Technology, Japan, ²NTT Facilities, Inc., Japan, ³Tokyo University of Agriculture and Technology, Japan

Alas, although I had begun the preparations for attending PVSEC-17, I was unable to get away that first full week in December. I believe I missed getting a sense of the Photovoltaic (PV) market vibe from Japan and the PV research underway in Japan and Asia.

Thanks are in order to Greentech Media, Nanosolar Chooses German Town for Solar Plant, and Earth2Tech, Nanosolar Starts Thin-Film Solar Panel Production, for linking to my In Search of Nanosolar GmbH post.