The Effect of Geometry on the Yield of Fresh Water from Single Slope Solar Stills

When examining the research literature relating to single slope solar stills it is apparent that much of the work has been conducted in an ad-hoc manner. This has led to several recommendations relating to the geometry of stills having developed that do not appear to have a sufficient evidentiary basis. To address this issue, this study used computational fluid dynamics simulations to examine the natural convection in single slope solar stills with cover angles between 0° and 60° and aspect ratios ranging from 1 to 8, with the results validated experimentally. Treating cover angle and aspect ratio as independent design variables showed that there are some features of the natural convection flow that account for the variation in yields reported in the literature (transitions between uni- and multi-cellular flow). More specifically, it was shown that the geometric effects could be correlated in the form of a generalized relationship and that this was able to predict the yield from several independent solar stills reported in the literature. As such, the use of the relationship will allow single slope solar stills designers to predict their yield far more accurately than is currently possible

Navigating Algeria towards a sustainable green hydrogen future to empower North Africa and Europe’s clean hydrogen transition

Algeria, richly-endowed with renewable resources, is well-positioned to become a vital green hydrogen provider to Europe. Aiming to aid policymakers, stakeholders, and energy sector participants, this study embodies the first effort in literature to investigate the viability and cost-effectiveness of implementing green hydrogen production projects destined for exports to Europe via existing pipelines. A land suitability analysis utilizing multi-criteria decision making (MCDM) coupled with geographical information system (GIS) identified that over 43.55% of Algeria is highly-suitable for hydrogen production. Five optimal locations were investigated utilizing Hybrid Optimization of Multiple Electric Renewables (HOMER), with solar-hydrogen proving the most cost-effective option. Wind-based production, offering higher output volumes reaching 968 kg/h, requires turbine cost reductions of 17.50% (Ain Salah) to 54.50% (Djanet) to achieve a competitive levelized cost of hydrogen (LCOH) of $3.85/kg with PV systems. A techno-economic sensitivity analysis was conducted, identifying Djanet as the most promising location for a 100 MW solar-hydrogen plant, with a competitive LCOH ranging from$1.96/kg to $4.85/kg.</p