{"title":"Data sampling speed versus energetic measurement errors in photovoltaic system monitoring","authors":"K. Kurokawa","doi":"10.1109/WCPEC.1994.520061","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520061","url":null,"abstract":"To measure solar irradiation and photovoltaic array output energy, measuring accuracy cannot be guaranteed unless the data sampling interval is appropriately selected. From this viewpoint, actual irradiance had been measured by comparatively high speed sampling of 1 to 4 seconds for 44 months and the daily errors of numerical integral has been estimated for various step sizes. Approximation formulae of the error versus the step size have been statistically obtained as well as their probability density function covering /spl plusmn/4/spl sigma/. Finally a nomograph is presented to decide an appropriate sampling interval. A concluding example shows that the deviating component of the error exceeding /spl plusmn/1% can happen once for every 1 month or 6 months if the step size is selected as 105 seconds or 65.5 seconds, in each of which the total error becomes -0.0485/spl plusmn/1% or -0.0336/spl plusmn/1% including an average error component.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74722677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Photovoltaics for household energy in Mongolia: experience and potential","authors":"B. Chadraa, A. Derrick, G. Purevdorge","doi":"10.1109/WCPEC.1994.521687","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.521687","url":null,"abstract":"Around 140,000 Mongolian families in rural areas rely on animal husbandry for their living, making this an important sector of the Mongolian economy. 81,000 of these families are nomadic, moving their tents and livestock to new pastures. Over one thousand PV power systems have now been installed in Mongolian households under national, UNDP and Japanese co-operation projects. As a result of studies and appraisals undertaken for UNDP and Danida, a marketing strategy is being developed for the commercialisation of photovoltaics. This paper reports on market study results and the development of financing mechanisms, rural credit and livestock product bartering.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74520778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"High conductivity CdS thin films formed by gas assisted chemical vapor transport (CVTG)","authors":"P. Sebastian, A. Sánchez","doi":"10.1109/WCPEC.1994.519971","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.519971","url":null,"abstract":"Formation of high conductivity CdS thin films by a new chemical vapor transport (CVT) method, employing a carrier gas, is reported for the first time. The film deposition was carried out in a quartz tube kept inside a tubular furnace. The chemical vapor transport was done using a screen printed film of CdS with CdCl/sub 2/ as the flux incorporated in the film. The nature of the film depends on parameters like condensation temperature, cooling rate, substrate position etc. The extrinsic films showed an electrical conductivity of the order of 10/sup 1/ (/spl Omega/ cm)/sup -1/ and the films which showed intrinsic nature exhibited a conductivity of the order of 10/sup -8/ (/spl Omega/ cm)/sup -1/. The new CVTG system is designed and further studies are in progress to obtain thin film solar cell structures employing this technique.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74341010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The waffle: a new photovoltaic diode geometry having high efficiency and backside contacts","authors":"Otto Leistiko, Microelectronics Centre","doi":"10.1109/WCPEC.1994.520225","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520225","url":null,"abstract":"By employing anisotropic etching techniques and advanced device processing it is possible to micromachine new types of mechanical, electronic, and optical devices of silicon, which have unique properties. In this paper the characteristics of a new type of photovoltaic diode fabricated employing these processing techniques are described. This novel device has not only high efficiency, but also has both contacts placed on the backside of the cell. The first devices which are only 50 mm in diameter are of relatively good quality with low leakage currents (nA), high breakdown voltages (80 V), and low series resistance (mohms). The measured efficiencies at AM 1.5 lie between 12 to 15% with short circuit currents of 25-30 mA/cm2, and open circuit voltages of 0.58-0.6 V.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74393862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of p-on-n GaInP/sub 2//GaAs tandem cells","authors":"P. Sharps, M. Timmons, Y. Yeh, C. Chu","doi":"10.1109/WCPEC.1994.520551","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520551","url":null,"abstract":"We report on the development of p-on-n GaInP/sub 2//GaAs two-terminal, monolithic cascade cells. The devices are of interest for space applications because they have higher efficiencies and power-to-weight ratios than existing single junction devices currently in use, they can be readily used in current satellite array designs, and they are compatible with current manufacturing capabilities at facilities such as the Applied Solar Energy Corporation. The p-on-n cascade cells have been grown at RTI by atmospheric pressure organometallic vapor phase epitaxy at 650/spl deg/C on n-type GaAs. The best device to date, with active area of 0.141 cm/sup 2/, has an active area efficiency of 20.1 percent under AM0 illumination, before an antireflection coating (ARC). Taking into account the ARC and a grid with a 5 percent obscuration, the device projects to a total area efficiency of 25.2 percent, nearly equal to that achieved for n-on-p cells. Devices of area 4 cm/sup 2/ have also been grown. The large-area devices have attained efficiencies of 21.8 percent under AM0 illumination, with ARC.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74578844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Single cell converter system (SCCS)","authors":"M. Wuest, P. Toggweiler, J. Riatsch","doi":"10.1109/WCPEC.1994.520084","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520084","url":null,"abstract":"Among the different concepts for solar cell module constructions, a new way of cell and module production has been proposed. An entire module-sized thin-film layer is used as one cell. This large cell delivers a voltage range of about 0.5-1.5 V, depending on the type of cell. To get an appropriate voltage level of 12 V DC or 230 V AC, it must be transformed by specially designed power converters. Investigations on a modular power converter have already been started at the power electronics laboratory of ETH Zurich. These investigations proved the feasibility of such a power converter. Because of the large area of this single cell, it produces a high current of about 100 A, depending on its efficiency and the module area. Alucobond, a compound of aluminium-polyethylene-aluminium, fullfils the needs for high current contacts perfectly, because the two aluminium plates can be used for this purpose.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73386916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Wenham, S. Robinson, X. Dai, J. Zhao, A. Wang, Y. Tang, A. Ebong, C. Honsberg, M. Green
{"title":"Rear surface effects in high efficiency silicon solar cells","authors":"S. Wenham, S. Robinson, X. Dai, J. Zhao, A. Wang, Y. Tang, A. Ebong, C. Honsberg, M. Green","doi":"10.1109/WCPEC.1994.519963","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.519963","url":null,"abstract":"Rear surface effects in PERL solar cells can lead not only to degradation in the short circuit current and open circuit voltage, but also fill factor. Three mechanisms capable of changing the effective rear surface recombination velocity with injection level are identified, two associated with oxidised p-type surfaces, and the third with two dimensional effects associated with a rear floating junction. Each of these will degrade the fill factor if the range of junction biases corresponding to the rear surface transition, coincides with the maximum power point. Despite the identified nonidealities, PERL cells with rear floating junctions (PERF cells) have achieved record open circuit voltages for silicon solar cells, while simultaneously achieving fill factor improvements relative to standard PERL solar cells. Without optimisation, a record efficiency of 22% has been demonstrated for a cell with a rear floating junction. The results of both theoretical and experimental studies are provided.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73927152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Hayashi, A. Ishikawa, Toshihito Endho, H. Yamagishi
{"title":"New type of large-area a-Si module produced using a polymer encapsulation method","authors":"K. Hayashi, A. Ishikawa, Toshihito Endho, H. Yamagishi","doi":"10.1109/WCPEC.1994.520016","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520016","url":null,"abstract":"A new type of amorphous silicon (a-Si) solar module has been developed, the back surface of which is encapsulated with a thermosetting polymer by using a spreading method. For this purpose, poly-olefin oligomer was chosen as an encapsulation layer and the process has been investigated. The modules show very little change in electrical performance under several types of acceleration test.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74017715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Narayanan, J. Creager, S. Roncin, A. Rohatgi, Z. Chen
{"title":"Process improvements for large area polycrystalline silicon buried contact solar cell sequence","authors":"S. Narayanan, J. Creager, S. Roncin, A. Rohatgi, Z. Chen","doi":"10.1109/WCPEC.1994.520189","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520189","url":null,"abstract":"One of the objectives of ongoing research at Solarex is to evolve process sequences that are compatible with high volume production, while reducing the processing cost of buried contact cells. In the paper, the impact of phosphorus gettering and the application of an antireflection coating with a higher refractive index than that of SiO/sub 2/ are discussed. Substantial improvement in the efficiency of the buried contact cells due to phosphorus gettering and incorporation of titanium dioxide antireflection coating is reported.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79310522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Z. Shi, W. Zhang, G. Zheng, V. Chin, A. Stephens, M. Green, R. Bergmann
{"title":"The effects of solvent and dopant impurities on the performance of LPE silicon solar cells","authors":"Z. Shi, W. Zhang, G. Zheng, V. Chin, A. Stephens, M. Green, R. Bergmann","doi":"10.1109/WCPEC.1994.520194","DOIUrl":"https://doi.org/10.1109/WCPEC.1994.520194","url":null,"abstract":"This paper reports the effect of solvent and dopant impurities on the performance of LPE silicon solar cells. For LPE layers grown from Sn and In based solutions and having similar surface morphology and resistivity, the performance of solar cells made on LPE layers grown from In was always higher than that of cells made on LPE layers grown using Sn as solvent. Consistently higher performance was also obtained from solar cells fabricated upon Ga-doped LPE layers than from cells made on Al-doped LPE silicon. The best cell was fabricated upon a Ga-doped LPE layer grown from In solution and had a total area efficiency of 16.4% confirmed by Sandia measurements. The observed phenomena are explained on the basis of Hall mobilities and minority carrier lifetimes of LPE layers grown from different solutions, and also the oxidation difference of these layers during cell processing.","PeriodicalId":20517,"journal":{"name":"Proceedings of 1994 IEEE 1st World Conference on Photovoltaic Energy Conversion - WCPEC (A Joint Conference of PVSC, PVSEC and PSEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1994-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84344844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}