Current Issue : July-September Volume : 2025 Issue Number : 3 Articles : 5 Articles
This study explores the potential for co-locating floating photovoltaics (FPVs) with existing hydropower plants (HPPs) in Ecuador. Ecuador’s heavy reliance on hydropower for electricity generation, combined with recent blackouts caused by prolonged dry seasons, underscores the importance of diversifying energy sources. The integration of FPVs with HPPs offers a promising opportunity to enhance energy security by reducing dependency on a single energy source and improving economic, electrical, and environmental outcomes. In this paper, we assess all HPPs in Ecuador and quantify the potential performance of FPV systems when installed at their sites. Our results show that FPV systems can not only contribute additional electricity to the grid but also improve HPP performance by reducing water evaporation from reservoirs and maintaining generation capacity during dry seasons, when solar irradiation is typically higher. To model the energy production, yield, and performance of the FPV systems, we applied RINA’s methodology to estimate representative weather conditions for each site and simulate FPV performance, accounting for system design loss factors. Additionally, we calculated the water savings resulting from FPV installation. Our findings reveal that, out of approximately 70 HPPs in Ecuador, 11 present favorable conditions for large-scale FPV deployment. Among these, Cumbayá HPP (40 MW) exhibited the most suitable conditions, supporting a maximum FPV capacity of 17 MWp. Marcel Laniado de Wind HPP (213 MW) and Mazar HPP (170 MW) were also identified as optimal candidates, each with potential FPV capacities equal to their installed HPP capacities. While this study primarily aims to provide scientific evidence on the potential of FPV-HPP co-location, the results and methodology can also guide Ecuadorian government authorities and investors in adopting FPV technology to strengthen the country’s energy infrastructure....
Carbon dots (CDs) featuring low-cost, non-toxic, and appealing optical properties demonstrate promising applications in energy, e.g. solar energy capture and conversion. However, it remains a significant challenge to expand the absorption bands of CDs from visible to near-infrared (NIR) spectral regions to harness the entire spectrum of sunlight for efficient solar energy utilization. Herein, hierarchical assemblies of CDs (HA-CDs) are constructed by stepwise assembling monodispersed ultraviolet-absorbing CDs to water-soluble visible-NIR absorbing supra-CDs (PA-CDs), and then complexing PA-CDs with Fe3+ ions to form 3D porous architectures (HA-CDs) with full solar spectrum absorption and good water resistance. Notably, the HA-CDs exhibit good hydrophilicity and superior photothermal conversion efficiency of 84% under simulated solar irradiation. The facile Fe3+ ion cross-linking assembly property enables the in situ preparation of HA-CDs on various fabric substrates, resulting in low-cost, high-performance photothermal conversion products. High-performance 2D solar-driven interfacial water evaporation, electricity generation, and water-electricity cogeneration have been demonstrated in the HA-CDs in situ coated fabric (HA-CDs-fabric). This study provides a novel and effective design approach for the development of high-performance CD-based photothermal materials for solar energy applications....
Ala‐Lahti et al. (2024, https://doi.org/10.1029/2024GL112922) present results from a global magnetohydrodynamic simulation of a single geomagnetic substorm for four scenarios: the original solar wind conditions, smoothed low‐frequency solar wind conditions, constant solar wind conditions with a boxcar averaged north/south component of the interplanetary magnetic field (IMF), and the boxcar‐averaged scenario with ultra‐low‐frequency (ULF) fluctuations. Smoothed (<1 mHz) solar wind parameters capture the bulk of the interaction, boxcar averaging reduces the energy flow through the system by 15%–40%, and ULF fluctuations (2–8 mHz) only enhance interactions by 5%–15%. From this, we conclude that low‐frequency plasma and magnetic field variations dominate the interaction. Further global simulations and observational studies of different events will be needed to determine the significance of intrinsic magnetopause and magnetotail instabilities (rather than directly driven interplanetary magnetic field fluctuations). They will also be needed to generalize these results for the full range of solar wind and geomagnetic conditions....
Three-dimensional flexible solar fabrics based on hydrogenated amorphous silicon (a-Si:H) thin film solar cells were prepared and characterized. A glass fiber fabric with a polytetrafluoroethylene (PTFE) coating proved to be a suitable textile substrate. Interwoven metal wires enable an integrated electrical interconnection. An array of solar cells consisting of an a-Si:H layer stack with a highly p-type/intrinsic/highly n-type doping profile was deposited onto it. Silver was used as the back contact with indium tin oxide (ITO) as the front contact. The best solar cells show an efficiency of 3.9% with an opencircuit voltage of 876 mV and a short-circuit current density of 11.4 mA/cm2. The high series resistance limits the fill factor to 39%. The potential of the textile solar cells is shown by the achieved pseudo fill factor of 79% when neglecting the series resistance, resulting in a pseudo efficiency of 7.6%. With four textile solar cells connected in a series, an open-circuit voltage of about 3 V is achieved....
This study examines the relationship between solar wind dynamics and geomagnetic activity during the ascending (ASC) and declining (DSC) phases of Solar Cycles (SCs) 23 (1996–2008) and 24 (2008–2019), which exhibited contrasting levels of solar activity. High-resolution solar wind parameters—including speed (SWS), plasma density (SWPD), temperature (SWT), and interplanetary magnetic field (IMF)—are analyzed alongside geomagnetic indices (Dst, ap, and Kp) to quantify phase-dependent relationships using correlation analysis and linear regression modeling. The results reveal significant differences in solar-terrestrial coupling between the two cycles. Sunspot number (SSN) and IMF exhibit comparable correlations (r ~0.7) across the ASC and DSC phases of SC 23 and SC 24. However, the correlation between SSN and SWT/SWS is stronger in SC 23 (r ~0.4/0.3) than in SC 24 (r ~0.3/0.2). Additionally, SWPD and SSN display a negative correlation during the ASC phases—more pronounced in SC 23—but no correlation during the DSC phases. SSN also exhibits a mild correlation with geomagnetic indices (r ≥ 0.3). The IMF demonstrates distinct relationships with SWT and SWS, maintaining a positive correlation of varying strength across phases, whereas its correlation with SWPD is negative during the ASC phases but positive during the DSC phases. Moreover, IMF, SWS, and SWT exhibit positive correlations with geomagnetic indices, though with varying strengths. These findings underscore the influence of SC amplitude and phase on the efficiency of solar wind energy transfer into Earth's magnetosphere. The efficiency of this transfer is not uniform but varies depending on the strength of the solar cycle and its phase. Stronger cycles (e.g., SC 23) generally facilitate more efficient energy transfer and enhanced geomagnetic activity. Furthermore, distinct solar wind-magnetosphere coupling mechanisms are evident in different phases, with coronal mass ejections playing a dominant role during the ASC phase and high-speed solar wind streams prevailing during the DSC phase, as suggested by previous studies. By contrasting two solar cycles with distinct characteristics—SC 24 being notably weaker—this study advances the understanding of long-term space weather variability and provides empirical constraints for models predicting geomagnetic responses to evolving solar wind conditions. The results highlight the necessity of phase- and cycle-specific approaches to enhance space weather forecasting and improve resilience across solar maxima and minima....
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