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36th European Photovoltaic Solar Energy Conference and Exhibition; 1681-1684, Effective utilization of renewable energy is a big motivation to renovate the conventional power systems toward smart energy systems. However, renewable energy is often small scale and intermittent. Hence, the online energy management is necessary to balance between demand and energy production. This paper proposes an online multi-scale optimization framework for smart PV systems in order to reduce the inherent complexity when trying solve the complete problem at a fine-grain time resolution. The proposed framework realizes the effective energy management by solving several optimization problems covering multi time scale. Experimental results shows that the proposed framework can reduce the purchased energy from the utility grid by 19.1% compared with other baseline methods.

36th European Photovoltaic Solar Energy Conference and Exhibition; 1261-1265, Bifacial photovoltaic technology is a promising, new approach to further reducing the Levelized Cost of Electricity of photovoltaic-generated electricity. However, designing and optimizing bifacial photovoltaic plants is a challenging task, which requires new modelling tools. This paper presents a physics-based energy yield simulation approach for bifacial photovoltaic systems, providing accurate yield prediction and insight into the operation of bifacial PV systems. Rear-side, inhomogeneous illumination is modelled using a CAD-assisted, GPU-accelerated ray-tracing-based approach, considering the influence of module build-up and layout, module frame, mounting structure and environment geometry. The non-uniform electrical-thermal operation with geometry-dependent convective and radiative cooling mechanisms and the resulting mismatch effect, which reduces module and system power output is modelled via interconnected electrical and thermal-equivalent circuits, where time-varying thermal resistors are used to model convective and radiative cooling. The combination of high-performance computing techniques, with advanced daylighting and circuit computing algorithms provides high accuracy at low computational costs, ensuring practical applicability to designing photovoltaic power generation system. The presented outdoor validation study confirms that our approach results in high accuracy, since the main mechanisms taking place during photovoltaic energy conversion are modelled on a physics basis. Additionally, physics-based modelling provides insight into the operation, the main loss contributions and mitigation strategies, applicable to bifacial PV systems.

35th European Photovoltaic Solar Energy Conference and Exhibition; 1201-1204, This contribution handles about BIPV modules made with plated bifacial n-PERT cells from imec. For the cell interconnection the advanced smart wire connection technology (SWCT) was used that can reduce silver consumption at cell level considerably. These modules were made for installation in a facade installation of the KU Leuven, with monitoring of module performance, weather conditions and module temperatures. The modules are all glass-glass, both transparent and white. The modules were inspected with EL, and I-V measurements at standard test conditions were performed (also from the back side for the transparent modules). The modules were installed in September 2017, monitoring started one month later. The most important finding was that the bifacial gain when using a white surface behind the module was only considerable when the modules were ventilated. The probable reason is that without ventilation, the extra heat generated by double-sided illumination results in a module temperature that is so high, that the decrease in Voc and FF almost completely compensates for the gain in Isc. The monitoring data still have to be analysed in more detail, including a comparison with energy yield calculations with the imec energy yield software that has been adapted for bifacial modules.

28th European Photovoltaic Solar Energy Conference and Exhibition; 309-311, In the past decade, a number of inventions have been patented, describing all a different technology to achieve spectral beam splitting for solar cells. This paper describes a novel light splitting device, that could solve some of the additional problems encountered by previous inventions, such as no overlap in photon frequencies, no moving parts, lightweight and lower influence by tracking errors. The practical optical efficiency of our device was calculated using available materials. Although there is still room for improvements, a calculated practical optical efficiency of 66% is reached.

Atomic layer deposition (ALD) of thin Al2O3 (