Exploitable results Thin film CIS PV module with improved performance and high long-term stability At project start in 2001 Würth Solar has delivered to the project standard CIS modules (60cm x 120cm) with efficiencies above 8%. Meanwhile the modules have been further improved and Würth Solar demonstrated CIS average efficiencies above 10%. Second generation CIS modules with output power at STC of up to 79W have been tested in the second field-test phase. The dc performance ratio relates the average efficiency of a module (defined as monthly sum of module output power divided by monthly solar irradiation on the module area) to the nominal STC efficiency (data sheet value given by the manufacturer). Most of the second-generation CIS modules have a DC performance ratio between 88% and up to 96%. The dependence of power on the operation temperature is similar to silicon; the power temperature coefficients are only marginally better than the silicon data. The performance under weak irradiance levels is also comparable to the low light performance of silicon PV modules. The main reason for the improved performance ratio is the characteristic increase of the module efficiency in the first weeks or even months after installation with a subsequent stabilisation of the module efficiency on a higher level. No degradation has been observed for the second-generation modules since the installation in spring/summer 2003. Accelerated ageing experiments have been performed and delivered no indications for stability problems. In the project, stability has been proven for a one-year period. This is still a minor part of the 20 years and more of expected lifetime. To date, we find no indication in the measurement results that a long lifetime with stable performance dates cannot be achieved. In conclusion, the CIS thin film PV technologies have proven their maturity and are ready for an introduction to the market. Electronic board for measurement of current-voltage characteristics of PV modules All measurement signals are connected to either of two data logger setups, each containing a CSI CR10X data logger, associated multiplexers and other peripheral equipment. The first one is dedicated to the I-V-curve measurements for all modules, whereas the second one performs the measurements of irradiances, temperatures, wind speed and direction and tracking angles. The measurement system for I-V curve recording uses a dedicated electronic load for each module to scan the module characteristic. Always four of the electronic loads reside on one printed circuit board (PCB). The logger can trigger and record three IV measurement channels in parallel and therefore it needs twelve scan cycles to grab the characteristics of all modules of the PYTHAGORAS installation. Software programs for acquisition and storage of raw data, editing of raw data from the logging system and for data analyses and presentation Software programs have been developed for the acquisition and storage of raw data, editing of raw data from the logging system and for data analyses and presentation. The primary functions of the programs include editing of the raw data from the data logging system to a form that enables the user to easily evaluate module performance and to make clarifying plots. This is done through the calculation of temperature and irradiance corrections to the performance parameters in the raw data, which makes it possible to compare measurement results, obtained in different weather conditions and thereby evaluate module performance as a function of time. The program can also be used to calculate performance data such as total electric power produced and power histogram data, as well as for evaluating the magnitude of the differences between the modules of a given technology. Field test performance data for CIS and CdTe thin film PV modules Equipment has been developed and installed for recording of : - Meteorological data (global and diffuse horizontal irradiance, ambient temperature, wind speed and wind direction, the plane of array irradiance on the fixed racks and on the tracker) and module temperatures from the fixed racks and from the tracker; - Module parameters (Isc, Voc, Vmp, Pmp) derived from the measured IV curves; - Sets of full IV-curve data from the test modules. CIS modules with output power at STC of up to 79W and CdTe modules with up to 50 W have been tested in the second field test phase. Sixteen modules of each technology are installed on fixed racks at solar energy test sites in Helsinki, Widderstall and Tenerife; the tilt angle is adapted to the latitude of the site; continuous field tests are performed since autumn 2001. Coefficients for parameter correction with respect to temperature and irradiance have been determined for open circuit voltage, short circuit current, fill factor and power. An empirical model has been developed to describe the outdoor module performance. For both technologies no degradation has been observed for the second-generation modules since the installation in spring/summer 2003. Accelerated ageing experiments have been performed and delivered no indications for stability problems of both CIS as well as CdTe. A successful market implementation is supported by outdoor performance data establishing a high level of confidence to the end user with respect to the quality and reliability of the product. Wyszukiwanie danych OpenAIRE... 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