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Several Cu2O and TiO2 thin films and four additional TiO2/Cu2O structures were fabricated by direct current (DC) magnetron sputtering. The process parameters were selected on the basis of earlier studies and numerical simulations. We examined the morphology of a cross-section of the PV structures, roughness and topography, and the transmission spectra of the thin films. Additionally, the properties of the samples were determined by X-ray diffraction. Next, the morphology cross-sectional and layer compositions of the solar cells was evaluated by scanning electron microscopy. Only one of the TiO2/Cu2O structures appeared smooth and homogeneous with columnar-type growth. For the as-grown films, diffraction peaks were observed and identified as brookite, rutile, CuO, and Cu2O and the average roughness of the samples was 0.5, 1.2, 5.4, and 4.0 nm, respectively. Finally, the transmission spectra of the thin films were recorded. Transmission and reflection spectra of ultraviolet-visible spectroscopy were analyzed, and the optical band gap and absorption coefficient of the oxidized layers were calculated. In the region of 400 to 1000 nm, transmittance varied from 5% to 70% in the TiO2 samples, and from 15% to 40% in the Cu2O samples, and reflectance of the TiO2 and Cu2O samples ranged from 20% to 90%. In the region of 1.5 eV to 3.5 eV, the mean absorption coefficient varied from ∼105 1/cm to ∼3 · 105 1/cm for TiO2 thin film, and from ∼2 · 105 to ∼6 · 105 1/cm for Cu2O thin film. The optical band gap values of the samples shifted slightly toward bulk anatase-3.5 eV, bulk rutile-3.1 eV, and copper(I) oxide. Finally, silver contacts were used for the electrodes. One of the fabricated TiO2/Cu2O PV structures was found to be sensitive to electromagnetic radiance during the experiment.

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In the paper the application of energy storage for enhancing distributed energy sources penetration and contributing to better quality of energy delivery to customers was investigated. A simulation method was used to study the effectiveness of complex control algorithms of energy storage system enabling load leveling and simultaneous voltage stabilization effect in grid-connected microsystem. The energy storage ability of grid forming and local power balancing after transition to island operation of the microgrid has also been examined.

The world energy consumption has exhibited high growth over the last several decades. Alternative energy sources like photovoltaic (PV) systems generate electricity, reduce pollution air, and have little environmental impact. The commonly used fixed-tilt solar panels, however, have low efficiency and high production cost. Thus, it takes a long time to obtain a return on the investment. Solar trackers increase the efficiency of PV systems and are therefore more attractive from a financial point of view. In order to design tracking systems that will be efficient, it is necessary to analyze the results during various periods during the year and over their lifespan. Thus, we performed a comparative study between fixed-tilt panels and the tracking system installed in Lodz, Poland. Fixed-tilt panels are at normal to the Earth's surface (90 deg from horizontal plane) and are attached to a building façade, azimuth 180 deg (S direction) with 15 cm ventilation gap so slight efficiency drop may be presumed. We performed short- and long-term analyses of the solar tracking and fixed-tilt systems, which allowed us to conclude that the panels tracking the sun had an additional gain of energy during the year as compared to the fixed-tilt panels. During some months, however, the solar tracking system did not produce as much energy as the fixed-tilt, vertically positioned panels. These results might be useful in designing and constructing solar tracking PV systems.