Solar Wall Technology and Its Impact on Building Performance

Solar walls provide transformative solutions by harnessing solar energy to generate electricity, improve thermal comfort, and reduce energy consumption and emissions, contributing to zero-energy buildings and mitigating climate change. In hot and humid regions, solar walls can reduce indoor temperatures by 30% to 50%, significantly improving energy efficiency. Optimizing the performance of solar walls includes factors such as glazing, shading, solar orientation, ventilation, and catalytic techniques, allowing them to be adapted to different climates. Innovative solar wall variants that include photovoltaic panels, water storage, and phase-change materials offer multifunctionality and sustainability in building design and are in line with global energy efficiency and environmentally conscious goals. In addition, innovative solar wall variants that combine photovoltaic panels, water storage, and phase-change materials promise even more sustainability in building design. These multifunctional solar wall systems can efficiently heat, cool, and generate energy, further reducing a building’s environmental impact. Solar walls have the potential to significantly reduce heating energy consumption; align with global goals for energy-efficient, environmentally conscious, and climate-responsive building design; and offer dynamic and adaptable solutions for sustainable architecture

Inkjet printed TiO2 nanoparticles from aqueous solutions for dye sensitized solar cells (DSSCs)

This is the accepted version of the following article: Cherrington, R., Hughes, D. J., Senthilarasu, S. and Goodship, V. (2015), Inkjet-Printed TiO2 Nanoparticles from Aqueous Solutions for Dye-Sensitized Solar Cells (DSSCs). Energy Technology., which has been published in final form at http://dx.doi.org/10.1002/ente.201500096This work reports on the formulation of suitable ink for inkjet printing of TiO2 by investigating the critical parame- ters of particle size, pH, viscosity, and stability. Aqueous sus- pensions of TiO2 nanoparticles (Degussa, P25) were pre- pared with the addition of 25 wt % polyethylene glycol 400 as a humectant to minimize drying at the printer nozzles and reduce the likelihood of nozzle blockage. The inkjet-printed TiO2 layers were assembled into dye-sensitized solar cells. The current–voltage (I–V) characteristics were measured under one sun (air mass 1.5, 100 mW cm 2) using a source meter (Model 2400, Keithley Instrument, Inc.), and the active area of the cell was 0.25 cm2. The inkjet-printed TiO2 photoanode produced a device with a short-circuit current (Isc) of 9.42 mA cm 2, an open-circuit voltage (Voc) of 0.76 V, and a fill factor (FF) of 0.49, resulting in a power conversion efficiency (PCE) of 3.50 %.Engineering and Physical Sciences Research Council (EPSRC

Sludge-derived biochar: Physicochemical characteristics for environmental remediation

The global production of fecal wastes is envisioned to reach a very high tonnage by 2030. Perilous handling and consequential exposition of human and animal fecal matter are inextricably linked with stunted growth, enteric diseases, inadequate cognitive skills, and zoonoses. Sludge treatment from sewage and water treatment processes accounts for a very high proportion of overall operational expenditure. Straightforward carbonization of sludges to generate biochar adsorbents or catalysts fosters a circular economy, curtailing sludge processing outlay. Biochars, carbonaceous substances synthesized via the thermochemical transformation of biomass, possess very high porosity, cation exchange capacity, specific surface area, and active functional sorption sites making them very effective as multifaceted adsorbents, promoting a negative carbon emission technology. By customizing the processing parameters and biomass feedstock, engineered biochars possess discrete physicochemical characteristics that engender greater efficaciousness for adsorbing various contaminants. This review provides explicit insight into the characteristics, environmental impact considerations, and SWOT analysis of different sludges (drinking water, fecal, and raw sewage sludge) and the contemporary biochar production, modification, characterization techniques, and physicochemical characteristics, factors influencing the properties of biochars derived from the aforestated sludges, along with the designing of chemical reactors involved in biochar production. This paper also manifests a state-of-the-art discussion of the utilization of sludge-derived biochars for the eviction of toxic metal ions, organic compounds, microplastics, toxic gases, vermicomposting approaches, and soil amelioration with an emphasis on biochar recyclability, reutilization, and toxicity. The practicability of scaling up biochar generation with multifaceted, application-accustomed functionalities should be explored to aggrandize socio-economic merits

Electronic structure, structural and optical properties of thermally evaporated CdTe thin films

Copyright © 2007 Elsevier. NOTICE: this is the author’s version of a work that was accepted for publication in Physica B: Condensed Matter. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Physica B: Condensed Matter (2007), DOI: 10.1016/j.physb.2006.04.008Thin films of CdTe were deposited on glass substrates by thermal evaporation. From the XRD measurements itis found that the films are of zinc-blende-type structure. Transmittance, absorption, extinction, and refractive coefficients are measured. Electronic structure, band parameters and optical spectra of CdTe were calculated from ab initio studies within the LDA and LDA+U approximations. It is shown that LDA underestimates the band gap, energy levels of the Cd-4d states, s-d coupling and band dispersion. However, it calculates the spin-orbit coupling correctly. LDA+U did not increase much the band gap value, but it corrected the s-d coupling by shifting the Cd-4d levels towards the experimentally determined location and by splitting the LDA-derived single s peak into two peaks, which originates from admixture of s and d states. It is shown that the sd coupling plays an important role in absorption and reflectivity constants. The calculated optical spectra fairly agree with experimental data. Independent of wave-vector scissors operator is found to be a good first approximation to shift rigidly the band gap of CdTe underestimated by LDA.Research Council of NorwayAcademy of Sciences of UzbekistanUniversity Grants Commission (UGC), Indi

Colour properties and glazing factors evaluation of multicrystalline based semi-transparent Photovoltaic-vacuum glazing for BIPV application

Low heat loss vacuum glazing offers high heat insulation for indoor space, which reduces the building’s heating energy demand. However, the transparent nature of this glazing allows similar daylight to double glazing that creates discomfort glare. Double pane semi-transparent type photovoltaic (PV) glazing introduces control of solar heat gain, daylight and generates clean electricity. The transparent portion between regularly distributed PV cells allows light penetration. Addition of these two technologies can offer low heat loss PV-vacuum glazing that will control heat loss, heat gain, and daylight and generate renewable power. In this work, two different areas of multicrystalline PV cells were employed to form 35% and 42% transparent PV-vacuum glazing. Spectral characterisation, glazing factor and entering light quality through the transparent part of this PV-vacuum glazing were evaluated. Colour rendering and correlated colour temperature of this glazing were compared with an electrically actuated switchable suspended particle device glazing

Optics for concentrating photovoltaics: Trends, limits and opportunities for materials and design

Concentrating photovoltaic (CPV) systems are a key step in expanding the use of solar energy. Solar cells can operate at increased efficiencies under higher solar concentration and replacing solar cells with optical devices to capture light is an effective method of decreasing the cost of a system without compromising the amount of solar energy absorbed. However, CPV systems are still in a stage of development where new designs, methods and materials are still being created in order to reach a low levelled cost of energy comparable to standard silicon based PV systems. This article outlines the different types of concentration photovoltaic systems, their various design advantages and limitations, and noticeable trends. This will include comparisons on materials used, optical efficiency and optical tolerance (acceptance angle). As well as reviewing the recent development in the most commonly used and most established designs such as the Fresnel lens and parabolic trough/dish, novel optics and materials are also suggested. The aim of this review is to provide the reader with an understanding of the many types of solar concentrators and their reported advantages and disadvantages. This review should aid the development of solar concentrator optics by highlighting the successful trends and emphasising the importance of novel designs and materials in need of further research. There is a vast opportunity for solar concentrator designs to expand into other scientific fields and take advantage of these developed resources. Solar concentrator technologies have many layers and factors to be considered when designing. This review attempts to simplify and categorise these layers and stresses the significance of comparing as many of the applicable factors as possible when choosing the right design for an application.From this review, it has been ascertained that higher concentration levels are being achieved and will likely continue to increase as high performance high concentration designs are developed. Fresnel lenses have been identified as having a greater optical tolerance than reflective parabolic concentrators but more complex homogenisers are being developed for both system types which improve multiple performance factors. Trends towards higher performance solar concentrator designs include the use of micro-patterned structures and attention to detailed design such as tailoring secondary optics to primary optics and vice-versa. There is still a vast potential for what materials and surface structures could be utilised for solar concentrator designs especially if inspiration is taken from biological structures already proven to manipulate light in nature

Colour properties and glazing factors evaluation of multicrystalline based semi-transparent Photovoltaic-vacuum glazing for BIPV application

Low heat loss vacuum glazing offers high heat insulation for indoor space, which reduces the building’s heating energy demand. However, the transparent nature of this glazing allows similar daylight to double glazing that creates discomfort glare. Double pane semi-transparent type photovoltaic (PV) glazing introduces control of solar heat gain, daylight and generates clean electricity. The transparent portion between regularly distributed PV cells allows light penetration. Addition of these two technologies can offer low heat loss PV-vacuum glazing that will control heat loss, heat gain, and daylight and generate renewable power. In this work, two different areas of multicrystalline PV cells were employed to form 35% and 42% transparent PV-vacuum glazing. Spectral characterisation, glazing factor and entering light quality through the transparent part of this PV-vacuum glazing were evaluated. Colour rendering and correlated colour temperature of this glazing were compared with an electrically actuated switchable suspended particle device glazing

Investigation of thermal and electrical performances of a combined semi-transparent PV-vacuum glazing

Combined semi-transparent PV-vacuum glazing provides low overall heat transfer coefficient, reduces solar heat gain, generates clean electricity and admits comfortable daylight. In this work, thermal and electrical performances of a multicrystalline silicon based PV-vacuum glazing were characterised using indoor test cell. For this particular combined system, PV covered 32% of the glazing area. Two different combinations of PV-vacuum glazing systems were manufactured where for the first case vacuum glazing faced test cell external environment (VPS) and for the second case vacuum glazing faced test cell internal environment (SPV). SPV type was found to have superior performance as PV cell achieved lower temperature than VPS type after 125 min exposure under 1000 W/m2 constant intensity from a simulator. For this type PV-vacuum glazing, overall heat transfer coefficient (U-value) was 0.8 W/m2 K and the solar factor was 0.42. U-value of this PV-vacuum glazing was 66% lower and the solar factor was 46% lower than PV double-glazing. Close power drop from PV due to elevated temperature was observed for both PV-double and PV-vacuum glazing

Studies on anode mass composition and cathode flow field design for small-scale to large-scale direct methanol fuel cell stack systems

In this research, the performance studies of a single cell Direct Methanol Fuel Cell with three different mass compositions (20%, 40%, and 60%) of platinum at anode infused in NiTiO3/C and multiple cathode flow fields, such as serpentine, parallel, and sinuous, with 25 cm2 active area. 40% platinum mass composition has been reported with a maximum power density of 24.42 mW/cm2, which is 26.8% and 10.4% higher than the performance observed in 20% and 60% platinum mass composition, respectively, on serpentine flow field. Among the various cathode flow fields, sinuous flow field provided the maximum power density of 28.69 mW/cm2, which is 17.48% and 53.83% higher in performance than that of serpentine and parallel flow fields, respectively. The best-performing catalyst mass composition and flow field, viz., 40% mass composition and sinuous flow field are scaled up to a 100 cm2 active area, and the results showed 16% lower performance compared to a 25 cm2 active area. A three-cell stack is fabricated with the best performing combination with the 100 cm2 active area that delivered a peak power output of 5.8 W, which resulted in 19.4% lower performance than 100 cm2. The stack was tested for stability for 48 h at constant voltage mode and was found that 0.002 W deviation for the entire period

Theoretical Investigation of the Temperature Limits of an Actively Cooled High Concentration Photovoltaic System

Concentrator photovoltaics have several advantages over flat plate systems. However, the increase in solar concentration usually leads to an increase in the solar cell temperature, which decreases the performance of the system. Therefore, in this paper, we investigate the performance and temperature limits of a high concentration photovoltaic Thermal system (HCPVT) based on a 1 cm2 multi-junction solar cell subjected to a concentration ratio from 500× to 2000× by using three different types of cooling fluids (water, ethylene glycol and water mixture (60:40), and syltherm oil 800). The results show that, for this configuration, the maximum volumetric temperature of the solar cell did not exceed the manufacturer’s recommended limit for the tested fluids. At 2000× the lowest solar cell temperature obtained by using water was 93.5 °C, while it reached as high as 109 °C by using syltherm oil 800, which is almost equal to the maximum operating limit provided by the manufacturer (110 °C). Overall, the best performance in terms of temperature distribution, thermal, and electrical efficiency was achieved by using water, while the highest outlet temperature was obtained by using syltherm oil 800