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33rd European Photovoltaic Solar Energy Conference and Exhibition; 880-883, In order to identify an optimum cell design in respect to cell width and corresponding front metallization finger grid design for cells used in shingled modules, simulations on the power output for cell stripes with varying width and front metal grid are performed. Based on this information, Al-BSF cells with a different amount of busbars are fabricated and cut into 4 to 6 stripes. For verification of the simulation a comparison between experimental and simulation results is made, which shows that the simulation predicts the correct cell to stripe power loss and hence could be used to find the optimum metallization layout. Further, these stripes are used to assemble different types of shingled mini modules to optimize the stripe overlap.

33rd European Photovoltaic Solar Energy Conference and Exhibition; 1762-1769, The new functional encapsulation layer which is presented in this study, known as conduction path on encapsulant (CPOE), has the potential to interconnect high efficiency IBC solar cells. In our study, single cell demonstrator modules were assembled reaching an efficiency of 19.3% with relative cell to module (CTM) losses below 2%. However, this concept so far requires reduction in the cell area (e.g. one-eighth cell size module design) since significant losses in FF were observed due to the high resistive losses in the CPOE. Accelerated environmental indoor tests reveal that the module based on CPOE technology passes the precondition ultra-violet (UV) degradation and damp heat (DH) exposure test for 1250 hrs. without any signs of degradation in the module packaging materials or electrically power losses. However, thermo-cycling for 200 cycles reveal relative Pmpp losses higher than 5%. Additionally, power degradation after applying a PID test at +1000V at 85°C was observed. Finally, outdoor energy yield studies of the CPOE modules compared with Zebra and p-type cell modules with soldered ribbons as references reveal higher energy yield (Ya) and performance ratio (PR) of CPOE and Zebra reference than p-type full cell module. In addition during cloudy days, CPOE modules show better energy performance when compared to Zebra reference modules.

32nd European Photovoltaic Solar Energy Conference and Exhibition; 1630-1634, The vertically mounted bifacial modules (VMBM) allow attractive applications, for example as a complement for smoothing the power peak at noon time (getting 2 peaks of power: morning and afternoon). Studies [1-3] indicate that in specific places, VMBM can obtain better performance than conventionally mounted mono-facial modules (CMMM). In the present work, the relevance for choosing an adequate mounting structure for VMBM facing east-west in desert climate conditions is investigated to reduce the self-shading impact, on module power, to a minimum. Five 60 cell modules were installed in El Gouna, Egypt, and their IV curves measured every minute. Results indicate that the mounting frame shading effect can easily turn on the bypass diode, diminish the power output up to approx. 10%rel. The DSM anti-reflective coated glass improves the mean energy yield for the VMBM by at least (4.2±0.2)%. The soiling test demonstrates that VMBM are practically unaffected by dust accumulation for this specific desert location. Extrapolating the results to a 1 MW PV plant, the tilted mounted bifacial modules (TMBM) generates more energy than CMMM and VMBM but this last one has the chance to produce more net energy than CMMM if the soiling effect is considered.

32nd European Photovoltaic Solar Energy Conference and Exhibition; 1635-1640, This work reports on the performance of photovoltaic systems installed at a coastal and inner zones of the Atacama Desert (Chile), at 1700 and 2400 m.a.s.l. Seven photovoltaic systems were studied for 19 months. The technologies installed at each place were a cadmium telluride thin film and a multicrystalline silicon PV plant at fixed angle of 10° for the coastal zone, 25° for the 1700 m high and 10° for the 2400 m high location. A Single Axis Tracking multicrystalline PV plant is also installed at 1700 m.a.s.l. The global horizontal irradiation reached 2488 kWh/m2·year. The solar irradiation at the plane of array for both plants at fixed angle was 2367 and 2863 kWh/m2·year for the coastal and inner zone respectively. The plant with single axis sun tracking received 3510 kWh/m2·year. The maximum rate by which the performance ratio decreased was –4.4 %/month for the plant at 1700 m due to the soiling over 11.5 months. The energy yield for location 1, 2 and 3 resulted in 1774-1590-1902 kWh/kWp·year for CdTe, 1440-1790-1665 kWh/kWp·year for mc-Si at fixed angle, respectively, and 2320 kWh/kWp·year for mc-Si with one axis tracking. The levelized cost of electricity was reduced up to 30% after cleaning.

31st European Photovoltaic Solar Energy Conference and Exhibition; 153-156, The physical and chemical properties of the encapsulation material define the long term stability of the module, its sensitivity to corrosion and potential induced degradation (PID) and the cell to module losses (CTM). Alternative materials to EVA do offer a possibility to increase the volume resistivity hence the stability against PID effect, better light transmissivity and enhanced stability during climatic testing. The paper investigated the performance of a newly developed encapsulation material, so called polyolefin elastomer (POE), on module level and compared it to the standard EVA material. For this we performed an investigation during damp heat (DH) testing for ribbons soldered or connected by means of conductive gluing to the solar cells. Further tests included extended humidity freeze (HF), a long-term PID, determination of cell to module losses for standard crystalline solar cells as well as IBC Zebra cells and the stability during thermo-cycling (TC). After 4400 hours of DH and HF40 test neither discoloration nor any larger power losses were found. The results after TC300 confirmed a superior performance for POE. We further found that samples with POE material show significantly less PID degradation and reduced CTM losses if compared to samples comprising EVA as encapsulation material.