Plenary talk at the EU-PVSEC 2015. Perovskite/crystalline silicon tandem solar cells are one of the most promising approaches to reach conversion efficiencies beyond 30 % at reasonable costs. Our research includes fundamental studies on the perovskite material properties such as sub-band gap absorption and complex refractive index, as well as the development of a broadband transparent rear electrode. The electrode development enabled the fabrication of semitransparent perovskite cells with efficiencies up to 14.7 %, which then translates to four-terminal tandem measurements with total stabilized efficiency of up to 22.8 %. Furthermore, we present first results on monolithic perovskite/silicon tandems with total current of 32.25 mA/cm2 on a flat wafer and finally provide optimization guidelines with optical simulations.
B.04 Guest lecture
COBISS.SI-ID: 11215444Performance of solar cells needs accelerated improvements. Optimized photon management is crucial for further improvement. By means of optical modeling light trapping techniques is reviewed, losses discussed and potential improvements using nanostructures presented.
B.04 Guest lecture
COBISS.SI-ID: 11216468The reliability is a key factor to achieve the planned energy yield of solar photovoltaic power plants. It is ensured by choosing good quality components when designing a photovoltaic system and by continuous monitoring of power output and rapid intervention at possible failures during the operation of the system. In this study, the photovoltaic system performance monitoring using performance models was analyzed. Due to gradual decrease of performance of the system caused by degradation, the new monitoring method was proposed. It includes the performance models with adjustable coefficients which are regularly updated in automatized procedure. This approach compensate for the ageing of the photovoltaic system and by analyzing the change of model coefficients during time the seasonal weather effect as well as ageing of the system can be evaluated. The proposed approach was validated by using measurements of photovoltaic system with rated power of 17 kW located in Ljubljana, Slovenia. The advantages of the method was found to be an automatized process of detecting faults and the possibility to additionally evaluate the sessional and ageing behavior of photovoltaic power plant.
B.04 Guest lecture
COBISS.SI-ID: 11348308To analyze the photovoltaic system potential for different locations and orientations, PV performance models coupled with solar irradiance databases are used. We have recently developed direct-diffuse-power-rating (DDPR) model that separately addresses the diffuse and direct irradiance components supplemented by angular loss compensation. In this study, the DDPR PV module performance model is extended to PV systems. The 17 kW PV system located in Ljubljana, Slovenia is used in this experiment to test the accuracy of the model which rendered 3.6% yearly root mean square error (RMSE) compared to 4.3% RMSE of basic model used as a reference. The major improvement occurs in the early mornings and late evenings when the diffuse component dominates. Also, the effect of longer averaging time intervals (which are usually utilized in many solar irradiance databases) on the accuracy of the PV performance models was researched. The averaging interval analysis showed, that up to 0.28% additional positive bias is induced for 1 hour averaging intervals compared to 5 minute one. With the use of the DDPR model’s feature of separating diffuse and direct irradiance, the model was used to estimate the loss or gain of PV system performance at different locations as well as orientations, different from optimal. The results for Ljubljana, Slovenia show that yearly temperature compensated performance ratio (PRT) can be 1.8% lower for certain orientations (e.g. vertical orientation facing south) compared to optimal orientation (south, 30° inclination) due to higher share of direct irradiance with higher solar incident angles. The contribution has been presented in the thematic area »Operation, Performance, Reliability and Sustainability of PV«, in which Blaž Kirn was honored by the »EU PVSEC Student Award«.
E.02 International awards
COBISS.SI-ID: 11472212In 2016 the largest global photovoltaic event, i.e. EU-PVSEC 2016 in Munich was chaired by Marko Topič. After the conference the web-based TV corporation SolarTV interviewed distinguished experts. Among them was also Marko Topic, who spoke about the amazing progress photovoltaics has achieved and about global trends in photovoltaics. https://www.photovoltaic-conference.com/home/interviews-2016.html https://www.youtube.com/watch?v=cppCn0PMvHQ
B.02 Presiding over the programming board of a conference
COBISS.SI-ID: 11651412