In the rural areas of the eastern Amhara region where livelihoods are predominantly based on agriculture with almost all the rural people earning their income from agriculture, awareness toward clean energy, and efficient appliances is at a very infant stage. As an indication, the research comes up with energy utilization is mainly of biomass-based with traditional stoves of very low efficiency. However, the future demand of the community toward the clean and improved efficient appliances has got a better preference over other energy technologies. Regarding the factor in determining the energy and energy appliance type choice, accessibility is found as the major reason.

The type of energy sources and energy technologies utilized for cooking and lighting have their own effect on health, environmental degradation, and overall economic development. Therefore, the primary objective of this study was to analyze the general trend of household energy source and energy technology utilization in rural areas of the Eastern Amhara region. The study utilized primary and secondary data collected over stratified systematically sampled households and from energy experts in the area. The study examined the utilization of various forms of energy and energy technology for the most common household energy-intensive processes (injera baking and stew cooking) as well as lighting. The development of different estimates across the whole population of the study region to indicate the relations among different factors was done through different statistical approaches; and the finding of the analysis revealed that 57.7% of the energy share is biomass-based firewood from which 99.5% of this source was used only for food preparation. The two main determinant factors of the community in selecting the energy types are found to be accessibility and health impact.

The technology around generating efficient and sustainable energy is rapidly evolving; hydrogen and fuel cells are versatile examples within a portfolio of options. This article provides an overview of the early-stage materials R&D in hydrogen and fuel cells at the US Department of Energy (DOE) Fuel Cell Technologies Office within the Office of Energy Efficiency & Renewable Energy. The article highlights technology status and progress toward achieving DOE targets, discusses R&D needs and challenges, and provides specific examples where advanced materials research is relevant to addressing those challenges. For broader context, materials R&D advances are discussed in the context of DOE’s H2@Scale initiative, which is enabling innovations to generate cost-competitive hydrogen as an energy carrier, enabling renewables, as well as nuclear, fossil fuels, and the grid, to enhance the economics of both baseload power plants and intermittent solar and wind, enhancing resiliency and avoiding curtailment.

Energy, water, and food shortages, along with irreversible environmental damage and climate changes, are bound to happen within a decade if the current course of action is maintained, preparing the “perfect storm” – a chain of interrelated events that could lead to major stress on the global system.

Energy plays a central role in the complex balance between humankind and the planet: poor strategies for the energy system will lead to disaster; but immediate, radical action can still mitigate what will otherwise be an unprecedented crisis. Reduction of the carbon intensity at the level of primary energy demand is one of the most impactful strategies. Current actions toward this goal, however, including the Nationally Determined Contributions (i.e., the climate actions pledged by the countries that ratified the Paris Agreements), are far from being adequate, and a much stronger effort is required. In this perspective, we draw inspiration from a visionary scientist of the past century, who pioneered the idea of a society powered by solar energy, and show, by a critical presentation of energy and carbon emission data, how this vision is now coming true. We focus our attention in particular to photovoltaics and analyze the factors that make it one of the key energy sources for the short and for the long term: economical convenience, the opening of very large markets, and the push by key players of the energy system.

Passive daytime radiative cooling (PDRC) is an electricity-free method for cooling terrestrial entities. In PDRC, a surface has a solar reflectance of nearly 1 to avoid solar heating and a high emittance close to 1 in the long-wavelength infrared (LWIR) transparent window of the atmosphere (wavelength λ = 8–13 μm) for radiating heat to the cold sky. This allows the surface to passively achieve sub-ambient cooling. PDRC requires careful tuning of optical reflectance in the wide optical spectrum, and various strategies have been proposed in the last decade, some of which are under commercialization. PDRC can be used in a variety of applications, such as building envelopes, containers, and vehicles. This perspective describes the principle and applications of various PDRC strategies and analyzes the cost, and economic and environmental consequences. Potential challenges and possible future directions are also discussed.

The sustainable integration of human activities into the global ecosystem is discussed, pointing out fatal anthropogenic heat as a major ecological problem and proposing global technical and economical solutions.

For human sake, we must get out of the “thermal age” and implement the “electroprotonic era” as soon as possible. Contrary to thermal power, electroprotonic is sustainable and can be produced by photoenzymatic systems, a cheap way to produce hydrogen (H2) or ammonia (NH3). We can accelerate the advent of this new era if we re-integrate external costs generated by thermal energies into their final prices. The author is leading the H2GREEN project in Belgium as an entrepreneur for more than a decade, which develops the photoenzymatic production of dihydrogen from water. The aim of the H2GREEN project is to contribute to the launch of a low-cost, renewable Hydrogen-based local economy as an energy carrier. Among the difficulties of this launch, the most important is certainly the lack of competitiveness due to the unfair competition of carbon products that externalizes their costs (CO2, oil spills, lethal pollution, armed conflicts, political oppression, foreign dependence, etc.).

This review focuses on state-of-the-art research and development in the areas of flexible and stretchable inorganic solar cells, explains the principles behind the main technologies, highlights their key applications, and discusses future challenges.

Flexible and stretchable solar cells have gained a growing attention in the last decade due to their ever-expanding range of applications from foldable electronics and robotics to wearables, transportation, and buildings. In this review, we discuss the different absorber and substrate materials in addition to the techniques that have been developed to achieve conformal and elastic inorganic solar cells which show improved efficiencies and enhanced reliabilities compared with their organic counterparts. The reviewed absorber materials range from thin films, including a-Si, copper indium gallium selenide, cadmium telluride, SiGe/III–V, and inorganic perovskite to low-dimensional and bulk materials. The development techniques are generally based on either the transfer-printing of thin cells onto various flexible substrates (e.g., metal foils, polymers, and thin glass) with or without shape engineering, the direct deposition of thin films on flexible substrates, or the etch-based corrugation technique applied on originally rigid cells. The advantages and disadvantages of each of these approaches are analyzed in terms of achieved efficiency, thermal and mechanical reliability, flexibility/stretchability, and economical sustainability.

Partial shading of Cu(In,Ga)(Se,S)2 (CIGS) photovoltaic (PV) modules is getting more attention, as is witnessed by the increase in publications on this topic in recent years. This review will give an overview of shading tests executed on CIGS modules and focuses on the more fundamental aspects that are often studied on cells. Generally, CIGS modules display very attractive performance under predictable row-to-row shading. However, potential damage could occur under nonoptimal shading orientations: module output after shading tests could reduce due to the formation of local shunts, often called wormlike defects. The influence of many factors on the formation of these defects, including the internal currents and voltages and the shape and intensity of the shade, will be discussed. This review allows an increased insight in the degradation mechanisms caused by partial shading, which would ultimately lead to the introduction of more shade-tolerant CIGS PV products in the future.

The effects of silicon incorporation on the in vitro and in vivo properties of magnesium phosphate (MgP) bioceramics were studied. Samples were prepared by conventional solid state synthesis method. Scanning electron microscopy and micro-computed tomography (µ-CT) analysis showed that Si doping reduces degradability of MgP. In vitro studies have shown that MG63 cells can attach and proliferate on MgP samples. Live/dead imaging showed that MgP–0.5Si sample had highest cell proliferation, which was also quantitatively confirmed by alamar blue assay. In vivo biocompatibility of MgP ceramics was assessed after implantation in rabbit model. Detailed µ-CT analysis showed new bone tissue formation around the implant after 30 and 90 days. MgP–0.5Si ceramics had 84% bone regeneration compared with 56% for pure MgP ceramics, as confirmed by oxytetracycline labeling. Our finding suggests that Si doping can alter physicochemical properties of MgP ceramics and promotes osseointegration, which can be a useful choice for bone tissue engineering.

A CoNiCrAlTaHfY/Co composite coating was prepared on the etched C/C composites by using duplex vapor phase surface alloying treatments, i.e., Co alloying and Co–Ni–Cr–Al–Ta–Hf–Y alloying. Microstructures and oxidation behavior of the coated C/C composites were analyzed by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. The result showed that the CoNiCrAlTaHfY/Co composite coating, 25 μm in thickness, was compact and composed of CrCoTa, AlCo2Ta, AlxCry, AlxNiy, and Co. The coating adhesion can be enhanced by microwave plasma chemical vapor deposition etching of matrix surface and adding a Co intermediate layer between the CoNiCrAlTaHfY top layer and C/C composites substrate. The honeycomb structure after etching was helpful to alloying element absorb and diffuse into substrate surface, and the composite coating continuation was improved by the Co buffer layer. After exposing in air for 180 min at 1000 °C, the bulk C/C composites volatilized while the loss rate of coated C/C composites was 0.82%, showing an improved oxidation resistance. Mixed oxides mainly containing Al2O3 and Cr2O3 were formed in the composite coating surface and protected the C/C composites from oxidation in air.

Planet–satellite-type supracolloidal clusters represent a comparably young class of nanomaterials, which are unique with regard to structural order. In this prospective article, different approaches for their synthesis are discussed and compared. These synthetic methods enable the engineering of supracolloidal structural and adaptive properties, which in turn enables different emerging applications, such as in sensing and catalysis. These possibilities are explored on the basis of selected recent examples. A perspective about possible future developments is given at the end of this article.

Molecular semiconductors synergize a variety of uniquely advantageous properties such as excellent absorption and emission properties, soft and deformable mechanical properties, and mixed ionic and electrical conduction. Over the past two decades, this outstanding set of features has put molecular semiconductors in the spotlight for a variety of optoelectronics and sensing applications. When it comes to mass-market adaptation, however, a challenge in these soft and van der Waals-bonded materials remains their electrical as well as environmental stability and degradation. This Prospective will summarize some of our current understanding of why organic semiconductors degrade with a strong emphasis put on the quintessential role played by water in this process. Furthermore, it will be revisited by which mechanisms water-related stability shortcomings might be addressed in the future and how these lessons can be translated to relevant hybrid systems such as perovskites and carbon nanotubes. Throughout this discussion, some parallels and key differences between organic and hybrid materials will be highlighted, and it will be elaborated on how this affects the associated device stability.

A hybrid graphene–gold nanomesh, realized through Au deposition on a patterned graphene nanomesh with a focused ion beam, is introduced and illustrated for enhanced light absorption in the visible spectrum. Numerical studies reveal that the hybrid nanomesh with dual resonances in the visible spectrum exhibit ~50% light absorption and enhancement factor as high as ~1 × 108. The simulations also show that the enhanced optical absorption is associated with the excitation of surface plasmons. This is confirmed through the localization of electric fields at the resonant wavelengths. Such a hybrid graphene–gold nanomesh exhibiting enhanced light-matter interactions paves the way toward plasmonics, surface-enhanced Raman scattering applications, etc.