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This study experimentally investigates the inclined solar still (ISS) with the incorporation of fins and natural bio-jute cloth under dynamic flow. Experiments are conducted on bright sunny summer days in Coimbatore, Tamil Nadu, India. The newly developed ISS features greatly support passive solar desalination. An increase in mass flow rate (Mf) increases heat transfer meticulously pointing out 0.65, 0.8, and 1 kg/min case absorber, and the water temperature difference is within 3°C. An Mf of 0.285 kg/min is secure for the maximum water temperature reach and clean water yield of 70°C and 4.1 kg/m2, respectively, along with jute cloth, it was 1.6 kg/m2 more against without jute cloth. The presence of a jute cloth cumulative water yield of 2.5 kg/m2 at 0.635 kg/min is very close to the absence of a wick cumulative yield of 2.3 kg/m2 during 0.285 kg/min. From these results, the authors conclude higher Mf is feasible to increase the still performance and clean water yield. The implementation of a fully renewable passive solar still is strongly recommended to attain renewable and sustainable desalination. HIGHLIGHTS The proposed modification of the still and wick substantially increases the water yield and reinforces the passive solar still desalination.; The presence of jute cloth has multiple benefits, such as porosity, and the height of the capillary effect enhance the evaporative rate by effective contact-making to absorber fin–wick–water.; A higher mass flow rate makes it possible to increase the still performance and clean water yield.;

Colombia has made different efforts to contribute to fulfilling its international commitments to curb climate change by reducing emissions and promoting technological development and project financing. However, the existing policies and regulatory framework primarily focus on promoting the photovoltaic industry for electricity production. Likewise, the energy sector has neglected the potential of solar thermal energy as a heat source. In this sense, it is necessary to redouble efforts through new public policies that integrate solar thermal energy in the residential and productive sectors. Using solar thermal energy for heating can contribute to the energy transition and meet its sustainable development goals. Therefore, the main objective of this work was to analyze Strengths, Weaknesses, Opportunities, and Threats to determine the potential application of thermal solar heat in Colombia while considering the local context. Factors such as their environmental conditions, policies, and regulations; the existence of international agreements; and their political status in general were analyzed. The analysis revealed Colombia's significant solar heat potential, enabling over 1.3 million cold-climate households to access hot water or reduce firewood use. Industrially, applying solar heat in 5% of the current industry could decrease fossil fuel consumption by 13 PJ. The findings highlight that Colombia's potential in thermal solar energy necessitates collaborative efforts, legislative reinforcement, climate-adaptive measures, and the resolution of political and social challenges. [ABSTRACT FROM AUTHOR]

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The decarbonization of the district heating (DH) sector is receiving attention worldwide. Solar energy and heat pump technologies are widely considered in existing and new DH networks. There is a need to understand the influence of solar energy on district heating experimentally. However, only a few university laboratories are focused on district heating aspects. Further, the concept of such laboratories is not adequately disseminated in the scientific literature. The main objective of this paper is to develop a conceptual design of a solar energy laboratory with a focus on district heating systems. The proposed concept forms part of the preliminary study carried out by a research group at the Tallinn University of Technology. First, a brief literature review on solar energy laboratory development is provided. Then, the conceptual design of such a laboratory is presented, along with a case study. Regardless of project size, the main components of a district heating-based solar energy laboratory are solar collectors, thermal energy storage (TES) tanks, and a control system. The proposed laboratory is expected to serve multiple roles, such as a practical laboratory to provide interdisciplinary courses for students, a research and experimental platform for researchers, and a cradle to achieve the campus green initiative. It is roughly estimated that the thermal energy output from the proposed laboratory would meet around 25% of the heat demand of the institutional building during the summer season (May, June, July, and August). It is expected that the present study will be a reference material for the development of innovative energy laboratories in educational institutions.

Space heating and hot water supply usually have great energy consumption in terms of household, industry, and other services which could be a big issue especially for the cold region. From technical and economic aspect, the present work investigates a hybrid sorption heat transformer (HSHT), which also plays a role of energy storage and upgrade. A renewable source or off-grid electricity is used for electricity supply while solar heat or ambient heat is regarded as heat inputs for two different scenarios. Composite ammonium chloride is used for further analysis of HSHT. Results indicate that HSHT could be a good candidate for the domestic heating in the cold region. Compared with vapor compression heat pump (VCHP), payback period (PBP) of HSHT could be reduced by up to 40%. Under different scenarios, PBPs are in the range from 2.48 year to 4.1 year. Also the levelized costs of heating of HSHT ranges from 20 $·MWh−1 to 46 $·MWh−1 for scenario 1 while the values of 64–133 $·MWh−1 could be obtained for scenario 2 which is up to 35.6% lower than that of VCHP. Carbon emission of HSHT system only accounts for 18% and 11% of that of gas boiler and VCHP, respectively. [ABSTRACT FROM AUTHOR]

The decarbonization of the district heating (DH) sector is receiving attention worldwide. Solar energy and heat pump technologies are widely considered in existing and new DH networks. There is a need to understand the influence of solar energy on district heating experimentally. However, only a few university laboratories are focused on district heating aspects. Further, the concept of such laboratories is not adequately disseminated in the scientific literature. The main objective of this paper is to develop a conceptual design of a solar energy laboratory with a focus on district heating systems. The proposed concept forms part of the preliminary study carried out by a research group at the Tallinn University of Technology. First, a brief literature review on solar energy laboratory development is provided. Then, the conceptual design of such a laboratory is presented, along with a case study. Regardless of project size, the main components of a district heating-based solar energy laboratory are solar collectors, thermal energy storage (TES) tanks, and a control system. The proposed laboratory is expected to serve multiple roles, such as a practical laboratory to provide interdisciplinary courses for students, a research and experimental platform for researchers, and a cradle to achieve the campus green initiative. It is roughly estimated that the thermal energy output from the proposed laboratory would meet around 25% of the heat demand of the institutional building during the summer season (May, June, July, and August). It is expected that the present study will be a reference material for the development of innovative energy laboratories in educational institutions. [ABSTRACT FROM AUTHOR]

Parabolic trough collectors and linear Fresnel collectors are mature technologies for power production, and they are being recently applied to provide solar heat for industrial needs. Conventionally, they use a liquid as heat transfer fluid, either thermal oil or water, to carry heat from the receivers up to the point of conversion or delivery. Although liquids offer excellent thermal properties, they show technical limitations, besides environmental concerns, which have encouraged the research on alternative solutions. This work reviews the main research works on the use of gases as heat transfer fluid in linear concentrating collectors, including solar power and heat production, highlighting the potential applications and technical challenges. The review indicates: first, gases offer potential to replace liquids, and second, there is a need for more research and development to define the best technical compromises to reach practical application in every sector. This article is categorized under:Sustainable Energy > Solar EnergyEnergy and Power Systems > Energy Infrastructure [ABSTRACT FROM AUTHOR]

The evacuated-tube collector (ETC) for solar heat production is one of the most efficient systems to convert Sun energy into usable energy. Unfortunately, some technological barriers are still present in solar-thermal heat systems that limit the use of these technologies to decarbonize processes. An important obstacle is the requirement for heat at stable temperatures, which is not always achievable by solar fields, e.g. variable sky. For that reason, in this work, we studied the phase-change materials embedded in the ETC to keep stable the water temperature for a short period (minutes, hours). In this study, carnauba wax was used as a sustainable phase-change material (PCM), to avoid the use of PCM based on hydrocarbon waxes. The PCM has been packaged using a polyethylene bag inserted into an ETC with heat-pipe technologies and tested. The collector has been tested outdoors under solar irradiation and under shading conditions. The experimental results show that is possible to detect a sensible effect of the PCM on the temperature using 4 kg of carnauba wax while there is an important effect on the temperature stabilization using 9 kg of PCM. Using 9 kg of the PCM, we observed a stability of the outlet water temperature at 65°C for 30 minutes under shading conditions. [ABSTRACT FROM AUTHOR]

The industrial sector demands 25% of global energy as heat, where one-third is used at temperatures below 150 °C. Nevertheless, the installed solar heating capacity in the industry is only 0.02%, even though the integration of solar heating systems into production processes could significantly reduce fossil fuel consumption at a competitive cost. Among other reasons, this low penetration is due to the final users' lack of knowledge of solar heating technologies. As a result, a free pre-feasibility assessment tool was developed for non-specialised users to evaluate the possibility of integrating solar heat into their processes using basic information. This tool uses transient simulation to estimate a feasible solar heating system through the parametric optimisation of the solar collection area, thermal storage volume, heat exchange capacity, and solar integration schemes at the supply level and costs. A commercial facility in Mexico was analysed using the developed tool as a case study. However, even when this is not a design tool, the calculated solar collector area, storage tank volume, and investment were only 2.1%, 9.0%, and 2.3% higher than reported by the solar designer. Pre-feasibility assessment tools are essential to overcome the certainty gap between end users and solar designers, thus enhancing the possibility of implementing solar heating systems in various commercial and industrial processes. [ABSTRACT FROM AUTHOR]

Paper discusses using a low-temperature biogas reactor with a solar support system technology as a management tool of biodegradable waste in small scale. A feasibility study looks at primary factors affecting anaerobic digestion process and solar heat production, design examination of a solar heating for anaerobic digester and possible technology application, also defines the multilocality of biogas, illustrates diffusion of innovation for diversification of biogas production. Analysis confirms solar heat increases efficiency and production of biogas, decreases costs and toxicity of digestate. Results show that for implementation of technology in rural areas further research in socio-economic, sourcing of feedstock and customization is needed. [ABSTRACT FROM AUTHOR]

The use of phase change materials (PCMs) in buildings is considered an effective way to reduce building heat flux and cooling input. In this study, a south-facing anti-theft door with PCM layer was simulated in hot summer weather in Rafsanjan city. The main purpose was decreasing the heat flux to buildings due to high temperatures and direct sunlight. Boundary conditions are set for the outside environment using local meteorological data, while indoor temperature is set at a constant degree (25 °C). Simulation studies were performed by changing the various materials inside the door and also by changing the type, thickness, and position of PCMs in different parts of the door. It was found that the use of PCMs along with a layer of extruded polystyrene commonly used in anti-theft doors can have up to 50% increased effect in reducing the heat transfer flux over a day compared with the conventional case. [ABSTRACT FROM AUTHOR]

Colombia has made different efforts to contribute to fulfilling its international commitments to curb climate change by reducing emissions and promoting technological development and project financing. However, the existing policies and regulatory framework primarily focus on promoting the photovoltaic industry for electricity production. Likewise, the energy sector has neglected the potential of solar thermal energy as a heat source. In this sense, it is necessary to redouble efforts through new public policies that integrate solar thermal energy in the residential and productive sectors. Using solar thermal energy for heating can contribute to the energy transition and meet its sustainable development goals. Therefore, the main objective of this work was to analyze Strengths, Weaknesses, Opportunities, and Threats to determine the potential application of thermal solar heat in Colombia while considering the local context. Factors such as their environmental conditions, policies, and regulations; the existence of international agreements; and their political status in general were analyzed. The analysis revealed Colombia’s significant solar heat potential, enabling over 1.3 million cold-climate households to access hot water or reduce firewood use. Industrially, applying solar heat in 5% of the current industry could decrease fossil fuel consumption by 13 PJ. The findings highlight that Colombia’s potential in thermal solar energy necessitates collaborative efforts, legislative reinforcement, climate-adaptive measures, and the resolution of political and social challenges.

For any thermoelectric effects to be achieved, a thermoelectric material must have hot and cold sides. Typically, the hot side can be easily obtained by excess heat. However, the passive cooling method is often limited to convective heat transfer to the surroundings. Since thermoelectric voltage is proportional to the temperature difference between the hot and cold sides, efficient passive cooling to increase the temperature gradient is of critical importance. Here, we report simultaneous harvesting of radiative cooling at the top and solar heating at the bottom to enhance the temperature gradient for a transverse thermoelectric effect which generates thermoelectric voltage perpendicular to the temperature gradient. We demonstrate this concept by using the spin Seebeck effect and confirm that the spin Seebeck device shows the highest thermoelectric voltage when both radiative cooling and solar heating are utilized. Furthermore, the device generates thermoelectric voltage even at night through radiative cooling which enables continuous energy harvesting throughout a day. Planar geometry and scalable fabrication process are advantageous for energy harvesting applications.

Photovoltaics (PV) and Solar Thermal (ST) collectors are sometimes competitors, as investment capacity, energy demand, and roof space are limited. Therefore, a ratio that quantifies the difference in annual energy output between ST and PV for different locations is useful. A market survey assessing the average price and performance both in 2013 and 2021 was conducted, showing a factor of 3 cell price decrease combined with a 20% efficiency increase, while ST showed negligible variation. Winsun simulations were conducted, and the results were plotted on the world map. Despite variations due to local climate, the ratio of energy production (ST/PV) increases at lower latitudes mainly due to (a) higher air temperature increasing ST output but decreasing the PV output; (b) solar radiation reducing ST efficiency to zero while having a minor impact on PV efficiency. The ratio was calculated for several ST operating temperatures. For latitudes lower than 66°, the ratio of a flat plate at 50 °C to a PV module ranges from 1.85 to 4.46, while the ratio between a vacuum tube at 50 °C and a PV module ranges from 3.05 to 4.76. This ratio can support the decision between installing ST or PV while combining different factors such as energy value, system complexity, and installation cost. [ABSTRACT FROM AUTHOR]

• An absorption-resorption heat pump (ARHP) experimental prototype was developed. • Actual heating performance was tested and discussed under different conditions. • Possible solar contribution and the sequent lift of primary energy efficiency was analyzed. • Solar heat utilization by its temperature zones based on the ARHP was designed and examined. Among thermally-activated heat pumps, absorption-resorption heat pump (ARHP) is dominant by the ability of combining with low-temperature heat for efficient space heating. In this work, an ARHP experimental prototype is developed based on the previous thermodynamic cycle and tested to obtain the operation details such as coefficient of performance (COP), supply water temperature, heating capacity and so on. The experimental and the previous theoretical results are compared and mutually verified. The exact performance of the solar-assisted ARHP heating system is then investigated and compared with that of the conventional vapor compression heat pump (VCHP) in terms of primary energy ratio (PER) and primary energy saving ratio (PESR). The experimental results show that the COP increases greatly from 1.125 to 1.353 when the heat source temperature increases from 90 °C to 150 °C at the ambient temperature and return water temperature of 0 °C and 30 °C, respectively. Under given conditions, the measured heating capacity reaches a maximum value of 18.5 kW, 9.0 % lower than the rated value. The theoretical results reveal that solar fraction above 30 % can make PER of the solar-assisted ARHP heating system comprehensively greater than that of the reference VCHP system. Optimal solar contribution to space heating can be achieved based on the proposed ARHP if solar heat is dividedly utilized in its temperature zones of 10–35 °C, 35–83 °C and above 83 °C. [ABSTRACT FROM AUTHOR]

Post-harvest losses caused by Callosobruchus maculatus is a major constraint to cowpea production and the improper use of synthetic insecticides by most farmers have resulted in environmental, health hazards, and development of insecticide resistance in insects. This study evaluates the efficacy of solar heat treatment using double-layered black polypropylene sheets in suppressing the development of the cowpea bruchid eggs and the effect of the heat absorbed on the germination potential of cowpea seeds. Five pairs of 2 – 3-day old adult C. maculatus were allowed to oviposit for ten days on 50 g cowpea seeds in a glass jar in the laboratory before exposure to 24, 48, 72 and 96 h solar heat treatment regimes. Infested cowpea seeds but not exposed to solarization was set along with the treatments while uninfested cowpea seeds was also set along and used as part of the germinability test. The experiment was laid out in a completely randomized design and treatments were replicated four times. The results showed that there were no significant differences among the number of eggs laid by adult C. maculatus on the cowpea seeds before solar heat treatment. Solar heat treatment of the cowpea seed at 24 h achieved 100% egg mortality of C. maculatus thus preventing adult emergence. The effect of solarization on seed viability showed that there were no significant differences between the infested cowpea seeds exposed to different solar radiation regimes when compared to uninfested cowpea seeds – range; 74% – 99% germination. The results showed that 24 h solar heat exposure of cowpea seeds in double-layered black polypropylene sheets could be the thermal death point of C. maculatus eggs on the seeds in the study area. [ABSTRACT FROM AUTHOR]

We study the role of solar heat in decarbonization of a Nordic district heating (DH) network, where most of the annual heat demand is satisfied with bioenergy. We use actual data from a Finnish municipality to create a dynamic model of the heating system with Apros® simulation software. With the help of modelling, we examine various decarbonization scenarios for the existing heating system, using different combinations solar thermal collectors, thermal energy storage (TES) and limitations on how and when solar heat can access the system. According to results, zero emissions during the summer can be achieved with annual solar share of 13.2% and at 44 €/MWh levelized cost of heat (LCoH), if the integration is supported by TES and a careful planning of solar heat integration. Our results show that a simple approach of pursuing for a maximal solar share does not necessarily lead to a reduction in carbon emission or in LCoH. In fact, aiming at higher solar shares of 15–25% in our case system, actually increase greenhouse gas emissions compared to the base case. This highlights the importance of focusing on emissions reductions instead of simple addition of renewable energy when DH utilities plan for solar heat investments. • Decarbonization of a Nordic district heating network with solar heat and bioenergy. • Simulation of different combinations of bioenergy, solar heat and energy storage. • Zero emissions during summer with solar share of 13.2% and heat cost of 44 €/MWh. • Solar heat integration requires energy storage and detailed integration strategy. • Higher 15–25% solar shares increase emissions without limitation on solar heat use. [ABSTRACT FROM AUTHOR]

This paper presents a thermodynamic model for predicting the cooling performance of a single-bed single-stage silica gel/methanol adsorption refrigeration system. Solar heat was collected through flat plate collectors and then stored in a hot water tank. Desorber bed was heated by the hot water from the hot water tank. The temperature of the desorber bed was varied from 65 °C to 85 °C, and its effect on system performance was observed. A numerical model was developed on the basis of mass and energy balance equations, adsorption equilibrium, and kinetic equations (Dubinin–Astakhov equation) for predicting the performance of the adsorption refrigeration system under the said conditions for four major parts (adsorber, desorber, condenser, and evaporator). A programing code was written in FORTRAN for solving these equations under pre-defined material properties, and the simulation result was observed. A refrigeration effect of 577 kJ with a coefficient of performance (COP) of 0.38 could be produced for a maximum bed temperature of 90 °C, which was restricted up to 90 °C because after this temperature, the input increases more than the refrigeration effect, and COP values reduce due to a reduction in desorption mass. [ABSTRACT FROM AUTHOR]

• Solar-assisted sorption-enhanced gasification of PET was simulated in AspenPlus. • Energy, exergy, and economic analyses of the process were conducted. • Energy efficiencies of day and night modes are 71.7% and 69.4%, respectively. • The highest exergy destruction appeared at solar radiation in the day mode. • The feasibility of the project is highly dependent on the benzene price. Although the recycling of polyethylene terephthalate (PET) bottles is well-operating in several countries, less than 10% of PET plastic waste was recycled in a closed loop globally, and the rest was discarded as leakage. A process to recover hydrogen and valuable chemicals through solar-assisted PET sorption-enhanced gasification was analyzed. PET steam gasification with CaO and solar-assisted calcium looping processes were already experimentally studied in our previous work to obtain optimized processing conditions. In this paper, the integrated process with product purification, steam power plant, and LiBr-H 2 O absorption chiller was simulated with Aspen Plus based on previous experimental results to investigate the techno-economic performance. Material flows, energy balance, exergy destruction, and economics were analyzed. Day and night mode operations at different seasons were evaluated based on energy balance and the weather conditions of Naples, Italy. The energy and exergy efficiencies of day and night modes varied between 62%–72%. The annual production yields of hydrogen and benzene were 684 t and 6286 t, respectively. Due to the high production of benzene, its higher price (>1092 €/t) would make the project feasible with a larger than 12% internal rate of return value and competitive break-even hydrogen price (less than 4 €/kg). The results show that this integrated process could be technically and economically feasible. It has the potential to be implemented for hydrogen and benzene recovery from PET plastic waste with sustainable solar heat source and zero fossil CO 2 emissions. [ABSTRACT FROM AUTHOR]

A novel strategy for the decarbonization of crude oil distillation was proposed considering two distillation columns located in Sicily that were simulated by adapting the equipment datasheet of the refinery Raffineria di Milazzo (RAM). The proposed approach consists of the integration of the topping section with a concentrating solar power (CSP) plant to decrease the carbon dioxide emissions and the consumed fossil fuels in the furnaces of the distillation columns. Three hypothetical scenarios of applicative interest were considered. In that most economically sustainable, the use of solar heat allowed a decrease of CO 2 emissions of 54.2 kt/year corresponding to a reduction of about 11% of the greenhouse gas emissions joined with the saving of 19.9 kt/year of methane with a rate of return of investment (ROROI) of 16.2%. As a comparison, if the land surface occupied by the CSP plant is used for photovoltaic production of green hydrogen considering an energy consumption of the electrolyzer of 4.70 kWh/Nm3, just 24.6 and 9.0 kt/year of CO 2 and methane respectively can be saved and the ROROI decreases to 8.5%. This study indicates that solar heat can be effectively and economically integrated in crude oil distillation to achieve a significant decarbonization of refineries. • Solar heat was integrated in the topping section of a refinery • Reduction of 11% of topping CO 2 emissions was achieved • CSP better than PV to decarbonize and decrease fuel consumption • Proposed strategy seems effective and economically sustainable [ABSTRACT FROM AUTHOR]

• A novel liquid air energy storage system is proposed. • Filling the gap in the crossover field research between liquid air energy storage and hydrogen energy. • New system can simultaneously supply cooling, heating, electricity, hot water, and hydrogen. • A thermoelectric generator is employed instead of a condenser to increase the hydrogen supply. • Energy, exergy, and economic analyses are conducted to evaluate the system performance. Liquid air energy storage (LAES) technology has received significant attention in the field of energy storage due to its high energy storage density and independence from geographical constraints. Hydrogen energy plays a crucial role in addressing global warming and environmental pollution. While there is substantial research in both domains, the investigation in the crossover field has not been made. To fill this gap, a novel LAES system coupling solar heat and hydrogen production is proposed, where solar energy is utilized as an external heat source to enhance the net power output. The system's performances are evaluated from the perspectives of energy, exergy, and economic viability. Under rated conditions, the novel system can generate 58,793.5 kW of electricity, 26,918.5 kW of cooling energy, 34,938.8 kW of heating energy, 67.94 kg/s of domestic hot water, and 12.17 mol/s of hydrogen. In comparison to the standalone LAES system, the novel system demonstrates a 20.76 percentage point increase in energy efficiency but undergoes a 14.61 percentage point reduction in exergy efficiency. The economic performance of the novel system has experienced substantial enhancement when compared to the standalone LAES system. Taking the Beijing region as an example, the net present value has risen by 422.38 million USD, the levelized cost of energy has decreased by 0.0818 USD/kWh, and the payback period has reduced by 7.47 years. Additionally, the impact of proton exchange membrane electrolyzer cell operating temperature, air turbine inlet temperature, electricity price fluctuations, and regional factors on the system performance are also investigated. [ABSTRACT FROM AUTHOR]

Photovoltaics (PV) and Solar Thermal (ST) collectors are sometimes competitors, as investment capacity, energy demand, and roof space are limited. Therefore, a ratio that quantifies the difference in annual energy output between ST and PV for different locations is useful. A market survey assessing the average price and performance both in 2013 and 2021 was conducted, showing a factor of 3 cell price decrease combined with a 20% efficiency increase, while ST showed negligible variation. Winsun simulations were conducted, and the results were plotted on the world map. Despite variations due to local climate, the ratio of energy production (ST/PV) increases at lower latitudes mainly due to (a) higher air temperature increasing ST output but decreasing the PV output; (b) solar radiation reducing ST efficiency to zero while having a minor impact on PV efficiency. The ratio was calculated for several ST operating temperatures. For latitudes lower than 66°, the ratio of a flat plate at 50 °C to a PV module ranges from 1.85 to 4.46, while the ratio between a vacuum tube at 50 °C and a PV module ranges from 3.05 to 4.76. This ratio can support the decision between installing ST or PV while combining different factors such as energy value, system complexity, and installation cost.

The data presented in this paper are related to the research article “Ammonia recovery from food waste digestate using solar heat-assisted stripping-absorption” [1]. The raw and filtered data are associated to daily monitoring of NH4 concentration of food waste digestate, pH of digestate and absorption solution and temperature of food waste digestate throughout experiments at different conditions. In addition, data of temperature monitoring in different points of solar-heat assisted stripping-absorption device are presented. The data could help further studies aiming to improve this system. The detailed data of these experiments could help to improve the performance and to reduce costs of nitrogen recovery from digestate using stripping-absorption technology.

The Geothermal Battery Energy Storage concept (GB) has been proposed as a large-scale renewable energy storage method. This is particularly important as solar and wind power are being introduced into electric grids, and economical utility-scale storage has not yet become available to handle the variable nature of solar and wind. The Geothermal Battery Energy Storage concept uses solar radiance to heat water on the surface which is then injected into the earth. This hot water creates a high temperature geothermal reservoir acceptable for conventional geothermal electricity production, or for direct heat applications. Storing hot water underground is not new, the unique feature of the GB is its application to sedimentary basins with formations that are water saturated and exhibit high porosity and high permeability. For certain reservoirs like these, calculations suggest that nearly 100% of the stored heat can practically be recovered, and long-term, even seasonal storage is possible. Several publications presented by the authors on the GB, parametrically identified desirable reservoir characteristics [14,17,18]. This is a review of those calculations and the inferred conclusions for a viable GB system. Potential GB system well configurations, injection and production scenarios and ultimate heat recovery for economic value are also noted. Image 1 • A concept to store large amounts of renewable energy daily to seasonally. • Reservoir characteristics for a geothermal battery system. • The conversion of solar or wind to geothermal electricity. • Subsurface sedimentary basin formations for large-scale hot water storage. • Solar heat collection to create a high-temperature geothermal reservoir. [ABSTRACT FROM AUTHOR]

Summary: Research and Innovation (R&I) on Large‐scale Industrial Solar‐thermal driven Drying technologies (LISDs) is one of the strategies required to transition to a low‐carbon energy future. The objective for this work is to guide future R&I on LISDs by defining the state of the art, gaps, and opportunities. To provide a high‐level perspective on the current state of solar drying research, results are presented from an analysis of the content relevant to LISDs found in 45 solar drying Review Articles published in journals over the past 25 years. A conclusion is that most of the existing solar drying research is not focused on LISDs. To build‐on these existing 45 solar drying Review Articles, results are presented from an analysis of 30 Original Research Articles with significant content relevant to LISDs published over the past 5 years. A gap is identified in coupling existing or slightly modified solar thermal collectors with existing or slightly modified industrial drying technologies to create indirect LISDs. To facilitate formulating new coupling strategies, the drying characteristics most relevant to this coupling are described and four fundamental classes of industrial dryer technologies are defined based on the underlying heat transfer mechanism, which then impacts the appropriate collector choice. At their most fundamental level, many of the technologies needed to couple solar collectors and industrial dryers to create novel indirect LISDs are not unique to indirect LISDs, but rather can be generalized across a wide range of Solar Heat for Industrial Processes (SHIP) applications, and integration issues are discussed at a more fundamental SHIP level. The technical and economic characteristics of 19 existing LISDs installations throughout the world are presented, and potential and emerging areas discussed. [ABSTRACT FROM AUTHOR]

The ability for controlling the light based on the angle of incidence played an essential role in many technological applications. In the present work, an angular optical filter consists of multilayers designed by Essential Macleod software within the visible and near-infrared regions. By using the transfer matrix method, we have obtained the transmission properties for the p-polarized light depending on the angle of incidence. The proposed filter can be easily used to control the transmission of visible and NIR light depending on the angle of incidence. Transmission of NIR at 1200 nm increases from 21.26 to 78.89% as the incident angle changed from 5° to 55°, respectively. Simultaneously, the transmission of the visible light is higher than 87%. These results may have a potential application in controlling the light and heat within the building, solar greenhouse, optical switch and other future applications. Also, the simplicity of the current structure makes it conducive to the industrial design using low-cost and massive product nanofabrication technique. [ABSTRACT FROM AUTHOR]

Considering works published in the literature for more than a decade (period from January 2008 till June 2019), this paper provides an overview of recent applications of the so-called “solar furnaces”, their reactors, process chambers and related devices, aiming specifically at the processing of (solid) materials. Based on the author’s own experience, some prospects on future trends are also presented. The aim of this work is to demonstrate the tremendous potentialities of the usage of solar heat for materials processing, but also to reveal the necessity of further developing solar-driven high-temperature technologies (which are required to displace the use of electricity or natural gas). In particular, it is essential to improve the temperature homogeneity conditions inside reaction chambers for materials processing using solar heat. Moreover, new innovative modular systems, practical and flexible, for capture, concentration, control and conduction of concentrated solar radiation are suggested. Solar thermal technologies for the production of electricity, as well as solar thermochemical processes for production of gases or liquids, are outside the scope of this review. [ABSTRACT FROM AUTHOR]

Liquid air energy storage (LAES) is a promising energy storage technology for its high energy storage density, free from geographical conditions and small impacts on the environment. In this paper, a novel LAES system coupled with solar heat and absorption chillers (LAES-S-A) is proposed and dynamically modeled. A power-speed control system is established for this system. Two operating control strategies are developed for the solar heat collection process. The transient characteristics of the novel system during the start-up, load-up process and encountering different disturbances are investigated. Besides, the dynamic responses when the waste heat is used for producing heating energy are also studied. The results indicate that the power-speed control system can guarantee a very short equilibrium time and a very small overshoot. The energy efficiency of the LAES-S-A system is 65.84 %, while that is 75.32 % when the waste heat is used for producing heating supply. When a disturbance occurs, the equilibrium times of the absorption chiller, air turbines and heating device are 1500 s, 40 s and 38 s, respectively. Compared with the absorption chiller, the heating device can better cooperate with the air turbines. The results can provide a reference for future studies. [ABSTRACT FROM AUTHOR]

Implementing innovation and sustainable development of district heating requires sound energy planning at the national and local levels. However, a research gap still exists on technically and economically viable solutions for developing fully decarbonized heat supply systems and assessing their environmental impact to provide a holistic analysis. Therefore, the case study-based research includes in-depth analyses of the current situation and existing operating conditions of the solar field, biomass and natural gas boilers, and thermal storage tank. The future fossil-free scenarios analyze the additional thermal storage capacity, and integration of heat pumps and local waste heat sources to reduce fossil fuel consumption, increase energy efficiency and minimize heat production costs. The results show that the waste heat utilization and heat pump integration allow to phase-out of natural gas for the peak load coverage. However, increasing thermal storage capacity by more than 50 % is crucial to store the thermal energy for peak demand-supply. The increased thermal storage tank volume allows higher biomass production rates and aligns the heat production with the available waste heat sources. The total heat production costs in a low-temperature heat pump scenario decrease by 5 %. The environmental impact assessment shows that the low-temperature heat pump scenario decreases the resource category by 61 % and the climate change category by 17 % in comparison with the Reference scenario due to higher solar yield and higher overall efficiency. • Research analyses multi-source district heating system decarbonization by integrating waste heat. • The waste heat from flue gas condenser and wastewater treatment plant is considered. • The thermal storage capacity increase and network temperature lowering are basic conditions for cost-optimal solutions. • EnergyPRO simulation model and life cycle assessment are merged to develop a holistic methodology. • Waste heat integration and heat pumps bring environmental benefits compared to biomass and fossil fuel combustion. [ABSTRACT FROM AUTHOR]

Recently, many researchers have put a spotlight on solar-assisted liquid air energy storage (LAES) system for its cleanliness and large storage capacity. However, the energy efficiencies of such systems are relatively low, resulting in poor economic performance. In addition, very few studies are conducted on the performance of such systems with multi-generation output. Thus, a novel solar-assisted LAES system with different operating modes (LAES-S-D) in different seasons is proposed, which fully utilizes the solar heat and air compression heat to supply cooling/heating/power/domestic hot water in different seasons to meet the energy requirements of users in different seasons. The waste heat recovery/utilization potential of the system is analyzed from the perspective of the energy cascade utilization. Energy, exergy, techno-economic and exergoenvironmental performances are deeply investigated. In contrast with the reference system, the energy efficiency is improved from 0.5101 to 0.5561 (transition seasons), 0.7849 (summer) and 0.8674 (winter), respectively. The net present value is improved by 324.63 million $, the levelized cost of energy is reduced by 0.0774 $/kWh and the dynamic payback time is decreased by 4.87 years. • A novel solar-assisted liquid air energy storage system is proposed. • Air compression heat, solar heat and air residual heat are all adequately used. • The waste heat recovery/utilization potential is analyzed. • Performance comparisons with reference system are performed. • The novel system shows a high energy efficiency and economic benefit. [ABSTRACT FROM AUTHOR]

• A novel hybrid solar-driven CL-SMR was proposed for hydrogen production. • The perovskites with substitutions at both A and B sites were investigated. • Ca2+ and Cu2+ substitutions in perovskite structure enhanced the reactivity. • La 0.1 Ca 0.9 Ni 0.9 Cu 0.1 O 3 showed good reactivity and regenerability in CL-SMR. Solar thermochemical cycle is considered a promising strategy for hydrogen production. The reaction process and oxygen carrier (OC) are the key issues for solar hydrogen production. In this study, a solar-driven chemical-looping steam methane reforming (S-CL-SMR) process by using perovskite as the oxygen carrier is proposed. In this process, the heat required by the endothermic reduction is supplied by solar heat, and the heat is converted into the chemical energy of solar fuels. Perovskites La 1−y Ca y Ni 0.9 Cu 0.1 O 3 were synthesized and characterized. Meanwhile, the reactivity was studied via thermogravimetry analysis at 400 °C for reduction, and 900 °C for re-oxidation. The results show that the reactivity of the La 1−y Ca y Ni 0.9 Cu 0.1 O 3 is improved as the calcium substitution increases. In the reduction reactor, the fractional oxidation of La 0.1 Ca 0.9 Ni 0.9 Cu 0.1 O 3 reaches to 0.61, and the methane conversion is about 52% with 60% CO selectivity. In the steam reactor, oxygen vacancies and reduced metal ions (Ni2+ and Cu2+) in doped perovskites can provide more active sites to break chemical bonds of H O. It is found that La 0.1 Ca 0.9 Ni 0.9 Cu 0.1 O 3 has the best reactivity, regenerability and high resistance to carbon deposition among the synthesized perovskites. Our study is expected to provide a promising potential for hydrogen production by mid-temperature solar heat. [ABSTRACT FROM AUTHOR]

Abstract In the present study a control system was developed and tested which allowed to maintain an optimum of both heat and microalgae production in a bioenergy façade and use of the heat to supply a residential building with hot water and heating. The control was developed for and implemented in the residential building BIQ Das Algenhaus , Hamburg, Germany. It automatically operates all system components of the 170 m² bioenergy façade as well as the management utilities which supply the building with heat. During a one-year monitoring in 2017/18, it was shown that the temperature in the culture medium of the bioenergy façade could be kept at the optimal cultivation temperature range between 20 and 35 °C. In addition to the biomass production, the façade produced heat as a result of the solar radiation. This heat has been extracted from the façade and utilized as a heat source for the building's supply system. The ratio between the solar radiation on the façade's surface and the heat produced – called energy conversion coefficient – was 0,38 across the year. The system supplied 59% of the building's annual total heat consumption of 63 MWh/a for hot water and heating. In the months May to August, the bioenergy façade served as the sole primary heat source for the building and the 50% surplus heat were stored in the soil below the building. The heat stored in the soil resulted in a regeneration of the soil temperature and allowed to cover the heat demand during winter. 80% of the heat extracted from the façade were used instantaneously and without intermediate storage. This indicates that the control optimally regulates the heat flows for direct use and thus minimizes storage losses. The results show that bioenergy façades can be perfectly integrated into cities to help transfer them from being places of abundant resource consumption to places of production of resources by producing heat and biomass concomitantly. [ABSTRACT FROM AUTHOR]

Abstract The present paper explored the potential of the seasonal solar thermal energy storage (SSTES) system using ammonia-based chemisorption for domestic application in the UK. The dynamic charging/discharging performance of the SSTES has been simulated using the real weather data with the solar thermal collector models, the domestic heating demand model and the chemisorption model. The selection of working salts has significantly influence on the system design and dynamic performance. The CaCl 2 -4/8NH 3 chemisorption can satisfy almost 100% of space heating demand when using low temperature hating facility during discharging stage, however, due to its relatively higher desorption temperature and limited sunlight available in the Newcastle-upon-Tyne the required solar collectors area exceeds the commonly available space of dwelling roof. The NaBr-0/5.25NH 3 chemisorption is only able to contribute 18.6% of heating demand because the temperature of the discharged heat cannot reach the required level for most of the time in the heating season. The best scenario studied was using BaCl 2 -0/8NH 3 chemisorption SSTES (45.2 m3 storage volume) combined with low temperature heating facilities and a 30.5 m2 solar collector, which can cover about 57.4% of space heating for a dwelling with a heat loss coefficient at 150 W/K. Highlights • Feasibility of domestic seasonal solar thermal storage using NH 3 chemisorption. • Integrate simulation of solar heat, domestic heating demand and NH 3 chemisorption. • Solar collector area, storage volume size and storage ratio using different salts. • BaCl 2 -0/8NH 3 was identified as the preferable working pair. [ABSTRACT FROM AUTHOR]