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Photovoltaics is amongst the most important technologies for renewable energy sources, and plays a key role in the development of a society with a smaller environmental footprint. Key parameters for solar cells are their energy conversion efficiency, their operating lifetime, and the cost of the energy obtained from a photovoltaic system compared to other sources. The optimization of these aspects involves the exploitation of new materials and development of novel solar cell concepts and designs. Both theoretical modeling and characterization of such devices require a comprehensive view including all scales from the atomic to the macroscopic and industrial scale. The different length scales of the electronic and optical degrees of freedoms specifically lead to an intrinsic need for multiscale simulation, which is accentuated in many advanced photovoltaics concepts including nanostructured regions. Therefore, multiscale modeling has found particular interest in the photovoltaics community, as a tool to advance the field beyond its current limits. In this article, we review the field of multiscale techniques applied to photovoltaics, and we discuss opportunities and remaining challenges.

Boron hydrolysis reaction can be used for onboard production of hydrogen. Boron is a promising candidate because of its low molecular weight and relatively high valence. The oxide product from this process can be reduced and the boron can be recovered using known technologies, e.g., chemically with magnesium or via electrolysis. In both routes solar energy can play a major role. In the case of magnesium, an intermediate product, magnesium oxide, is formed, and its reduction back to magnesium can exploit solar energy. The boron hydrolysis process at moderate reactor temperature up to 650[degrees]C, potentially suitable for use in vehicles, has not been sufficiently studied so fur. This paper addresses the operational requirements using an experimental setup for investigating the hydrolysis reaction of metal powders exposed to steam containing atmosphere. The output hydrogen is measured as a function of temperature in reaction zone, steam partial pressure, and the different steam to metal ratio. Test results obtained during the hydrolysis of amorphous boron powder in batch experiments (with 0.1-2 g of boron, water mass flow rate of 0.1-1 g/min. carrier gas flow rate of 100 [cm.sup.3]/min at total atmospheric pressure with steam partial pressure of 0.55-0.95 bar abs) indicate that the reaction occurs in two different stages, depending on the temperature. A slow reaction starts at about 300[degrees]C and hydrogen output increases with reactor temperature and steam partial pressure. The fast stage starts as the reactor temperature approaches 500[degrees] C. At this temperature, the reaction develops vigorously due to higher reaction rate and its strong exothermic nature. The fast stage is self-restrained when 50-60% of the loaded boron is reacted and 1.5-1.8 SPT L [H.sub.2] per 1 g of boron is produced. Raising the temperature before the steam flow starts during the preheating period above 500[degrees]C increases the hydrogen yield at the fast stage. Then, the reaction continues for a long time at slow rate until the hydrogen release is terminated. The duration of the fast step decreases sharply with the increase of the steam to boron ratio. [DOI: 10.1115/1.2807215] Keywords: boron, hydrolysis, hydrogen for transportation, solar fuel

Boron has been proposed as a candidate for hydrogen production. In this study a process is described in which boron is used as a means to store and transport solar energy from a production site to motor vehicles, where it is used to generate hydrogen and heat. The proposed multi-step fuel cycle includes no carbon as a reducing agent and, therefore, no release of C[O.sub.2] to the atmosphere. This process is safe, mostly involving harmless materials and well-understood technologies. It eliminates the distribution, storage, and pumping of hydrogen at the refueling station, and diminishes the amount of hydrogen stored on the vehicle to a minimum. It is shown that the boron reaction with water, performed on-board of a vehicle, has high hydrogen storage capacity based on both volume and mass, compared with other candidate technologies. An energy balance of the entire process predicts that the overall efficiency of converting solar energy to work by the vehicle engine can be about 11%. Keywords: Boron; Thermochemical storage; Solar energy; Distribution

Israel's Southern Arava region has experienced a boom in solar infrastructure development since 2011. Public acceptance of renewable energy installations is key to their successful implementation. The objective of this paper is to understand the level of acceptance of solar installations among Southern Arava communities and identify the factors that contributed to the widespread implementation of solar infrastructure in the region. Surveys and semi-structured interviews were distributed to five local kibbutz communities and local solar developers to gauge their attitudes about renewable technology in general and their acceptance of solar installations in their community. The results point to strong acceptance of solar technology in this region. Several factors contributed to this high level of support including kibbutz co-ownership of solar assets, transparent communication between stakeholders, and the kibbutz decision-making structure. [ABSTRACT FROM AUTHOR]

Palestine faces considerable challenges relating to its energy supply, which is reflected in its dependency on imported electricity and fuels. This makes it vulnerable to changing political and economic situations and emphasises the urgent need to search for alternative and sustainable sources of energy from within Palestine itself. This study explores the potential energy generation from olive cake (OC) in the Palestinian territories. The findings of the study confirmed that there is a high-energy potential to be derived from OC and that powering olive mills by small-scale generators using OC is feasible. It was found that the amount of electricity that can be produced by OC combustion constitutes about 1.3% of all electricity consumption in 2009. Furthermore, numerous environmental benefits can be derived from using OC as biomass, notably the reduction of hazardous emission and the reduction of untreated OC. [ABSTRACT FROM AUTHOR]