This research investigates the contribution of dust to the long-term performance degradation of various photovoltaic (PV) modules that have been operating for almost eighteen years without any cleaning procedures at the Renewable Energy Outdoor Testing Area (ROTA), Murdoch University, Perth, Australia. A solar module analyser was used to assess the PVs’ electrical performance, while a combination of spectrophotometer, scanning electron microscope, electron dispersive spectroscope and X-ray diffraction were used to exam the properties of the dust on the panels. The study found that the degradation of the PV modules’ power output, ranged from 19% to 33%. The degradation is mostly due to non-dust related factors such as corrosion, delamination, and discoloration, which account about 71–84%, although the contribution of dust is still significant at 16–29%. Anova analysis shows that the dust has a fairly uniform impact on the performance degradation of all PV technologies at ROTA. This is in line with the results of spectral transmittance curves for different dust density samples that essentially flat over the wavelength range of the PV modules. An investigation of the properties of dust revealed that dust particles deposited on PV modules’ surface at ROTA were dominated by fine particles built of large amounts of quartz (SiO2), followed by calcium oxide (CaO) and some minors of feldspars minerals (KAlSi3O8), which are the main factors in transmittance losses that affect PV module performance.

Nickel-based bimetallic oxides (BMOs) have shown significant potential in battery-type electrodes for pseudo-capacitors given their ability to facilitate redox reactions. In this work, two bimetallic oxides, NiMoO₄ and NiWO₄, were synthesized using a wet chemical route. The structure and electrochemical properties of the pseudo-capacitor cathode materials were characterized. NiMoO₄ showed superior charge storage performance in comparison to NiWO₄, exhibiting a discharge capacitance of 124 and 77 F·g⁻¹, respectively. NiMoO₄, moreover, demonstrates better capacity retention after 1000 cycles with 87.14% compared to 82.22% for NiWO₄. The lower electrochemical performance of the latter was identified to result from the redox behavior during cycling. NiWO₄ reacts in the alkaline solution and forms a passivation layer composed of WO₃ on the electrode, while in contrast, the redox behavior of NiMoO₄ is fully reversible.