Photovoltaic, as an emerging technology, has become an alternative to traditional fossil energy to provide energy. At present, the electrical efficiency of photovoltaic modules can only reach about ...30 %. Most of the solar radiation is converted into thermal energy and remains on photovoltaic modules, resulting in high temperature during the operation of photovoltaic modules. When the photovoltaic panel is in the case of continuous high temperature, the photoelectric conversion efficiency will continue to decline. At present, photovoltaic thermal management technology can effectively solve such problems. Photovoltaic thermal management technology based on phase change materials (PCM) has also been studied by many experts. This paper first introduces how PCM reduces the operating temperature and working principle of photovoltaic panels, and summarizes PCMs for various applications and photovoltaic systems. In fact, the research progress of PCM-based photovoltaic thermal management system in recent years is summarized in detail, including non-concentrating photovoltaic thermal management system, concentrating photovoltaic thermal management system, photovoltaic thermal (PV-T) thermal management system, photovoltaic-microencapsulated phase change material and phase change material-nanofluid. I hope this paper can provide better ideas and methods for the research of PV thermal management technology based on PCM. Finally, the future research priorities and prospects based on PCM photovoltaic thermal management technology are proposed. It is not yet in the mature stage of development, and the follow-up specific research is still challenging.
•This paper reviews PCM for photovoltaic thermal management.•The experimental and simulation research progress of photovoltaic thermal management is reviewed.•The challenges and development directions of PCM photovoltaic thermal management are reviewed.
One key component of the energy demand in the built environment is the thermal energy required for domestic hot water preparation. Currently, fossil fuels are mostly used to meet the thermal energy ...demand in the built environment, lately, solar thermal systems have been increasingly implemented, mainly for domestic hot water preparation, enhancing the building's sustainability. A case study is presented in the paper for a solar thermal system with six flat plate ‒ and three evacuated tube solar thermal collectors installed on the rooftop of the Renewable Energy Systems and Recycling Research Centre, in the Colina Campus of the Transilvania University of Brasov, Romania. In 2017, this system provided 17,412 kWh of thermal energy to prepare domestic hot water for a Solar House and for the Sports Hall locker rooms. Evacuated tube solar thermal collectors showed better specific thermal output than flat plate ones.
The paper provides the analysis of fuel and energy transition in households sector and its sustainable development in the period 2004–2019. The main purpose of the paper is to determine the ...development trends in the use of renewable energy sources (RES) in the EU countries household sector in 2004–2019, to recognize the state of development and functioning of the studied area as well as to indicate their successes and shortcomings in observed reality. The article employs the results of Energy balance sheets from Eurostat. The research entity were households from 28 European Union countries, with particular emphasis on households from Poland and selected neighboring countries. The research subjects there were different sources of renewable energy used by households, i.e., solar thermal system, geothermal technologies, primary solid biofuels, charcoal, biogases, blended biogasoline, blended biodiesels, ambient heat (heat pumps). To achieve the research objective a number of statistical measures ands methods, including cluster analysis and linear trend indicator applied. In the analyzed 16 years, an absolute and relative increase in the use of RES in the household sector was noticed. Taking into account the specificity of using RES in households, 6 clusters of countries were distinguished. In Poland, it was noted that there was a significant increase in the use of RES in households, with stagnation in the use of non-renewable energy sources, such as, for example, hard coal.
Ghana has the potential to deploy solar energy technologies, with its solar irradiation varying between 4 and 6.5 kWh/m2/day. However, the country's dependence on fossil fuels for generating ...electricity and heat remains prevalent. This study aims to assess the technical and financial feasibility of installing solar water heating (SWH) systems in hotels within Ghana. RETScreen software is used to conduct the technical, financial, and emission analyses of the SWH system for five cities in Ghana, including Accra, Cape Coast, Kumasi, Tamale, and Wa. The findings show that SWH systems are feasible for Ghanaian hotels, with solar fractions ranging from 61.2% in Kumasi to 78.5% in Wa. Also, installing the SWH system yields a positive net present value for all the cities. The implication is that installing SWH systems in hotels operating in Ghana is financially viable and attractive for investment. In addition, payback periods infer that the SWH systems can generate a return on investment in a reasonable time frame, especially considering the equity payback period. Furthermore, about 58.7 tonnes of carbon dioxide (CO2) emissions could be avoided annually by installing the SWH system in the selected cities. This study's findings suggest that hotels can achieve long-term financial savings on electricity costs by utilising solar energy to heat water. This, in turn, reduces their reliance on fossil fuel consumption while actively pursuing their sustainability objectives. The study findings are crucial in assisting hotel owners in making informed decisions on SWH systems.
The demand for clean energy is strong, and the shift from fossil-fuel-based energy to environmentally friendly sources is the next step to eradicating the world’s greenhouse gas (GHG) emissions. ...Solar energy technology has been touted as one of the most promising sources for low-carbon, non-fossil fuel energy production. However, the true potential of solar-based technologies is established by augmenting efficiency through satisfactory environmental performance in relation to other renewable energy systems. This paper presents an environmental life-cycle assessment (LCA) of a solar-photovoltaic (PV) system and a solar-thermal system. Single crystalline Si solar cells are considered for the solar PV system and an evacuated glass tube collector is considered for the solar thermal system in this analysis. A life-cycle inventory (LCI) is developed considering all inputs and outputs to assess and compare the environmental impacts of both systems for 16 impact indicators. LCA has been performed by the International Reference Life Cycle Data System (ILCD), Impact 2002+, Cumulative Energy Demand (CED), Eco-points 97, Eco-indicator 99 and Intergovernmental Panel on Climate Change (IPCC) methods, using SimaPro software. The outcomes reveal that a solar-thermal framework provides more than four times release to air ( 100 % ) than the solar-PV ( 23.26 % ), and the outputs by a solar-PV system to soil ( 27.48 % ) and solid waste ( 35.15 % ) are about one third that of solar-thermal. The findings also depict that the solar panels are responsible for the most impact in the considered systems. Moreover, uncertainty and sensitivity analysis has also been carried out for both frameworks, which reveal that Li-ion batteries and copper-indium-selenium (CIS)-solar collectors perform better than others for most of the considered impact categories. This study revealed that a superior environmental performance can be achieved by both systems through careful selection of the components, taking into account the toxicity aspects, and by minimizing the impacts related to the solar panel, battery and heat storage.
•A solar-hydrogen CHP system integrated with solar-thermal collectors considered.•Multi-objective sizing optimisation using genetic algorithm performed on the system.•The electric reliability of the ...optimal solutions in favour is always equal to 100%.•The maximum thermal reliability that could be obtained in the pareto front is 96%.•Trade-off between the cost of energy and percentage of wasted power from PV.
A sizing multi-objective optimisation using the genetic algorithm is performed on a solar-hydrogen combined heat and power system integrated with solar-thermal collectors (SH CHP-ST) to supply both power and heat (i.e. hot water demand) to an application. A solar-hydrogen system is a renewable system with hydrogen-based storage consisting of an electrolyser, a hydrogen tank, and a fuel cell. The fuel cell generates heat while producing power that can be recovered. The heat collected from the fuel cell can be integrated with the heat supply of a renewable solar-thermal system consisting of an evacuated tube collector and a hot water storage tank. A simulation module to model the operation of the whole system is implemented in MATLAB. Energy demands and meteorological data for a remote household located in southeast Australia are considered. The sizes of the main components of the system are optimised with the objectives of maximising the overall reliability of the system, minimising the levelised cost of energy, and minimising the percentage of excess energy from the PV that is not utilised. The results show that the electric reliability of the optimal solutions in favour is always equal to 100%. The maximum thermal reliability that could be obtained is around 96%. A trade-off between the cost of energy and percentage of wasted power from PV is found.
•A novel parabolic trough solar-nuclear combined (SNC) system is proposed.•This SNC system is used for power generation and sea water desalination.•Exergy analysis of the SNC system is conducted.
A ...novel solar-nuclear combined (SNC) system is proposed for both electricity production and sea water desalination. A parabolic trough solar thermal system and a small modular reactor (SMR) based on pressurized water reactor technology are coupled in this system. By using the Ebsilon code, the operation behavior and exergy evaluations of the SNC system are launched under both the design point and varying solar irradiance conditions. The results demonstrate that the output electric power and electric efficiency of the SNC system are 258.4 MW and 35.2% when the solar irradiance is 900.0 W·m−2. The output electric power, incremental electric power and electric efficiency of the SNC system all increase as the solar irradiance increases. The maximum exergy loss occurs in the parabolic trough solar receiver. The exergy efficiency of the parabolic trough solar receiver is 51.7% when the DNI increases to 1000.0 W·m−2.
In antiquity, people already knew the principles of solar architecture, designing their houses to the south to take advantage of the sun in all seasons. Today, solar architecture is undergoing a true ...revolution because of the development, among other things, of special facades involved in the processes of heating, ventilation, thermal isolation, shading, electricity generation and lighting of homes: these are called “solar facades”. This paper aims to review the remarkable developments that have occurred during the first decade of this century in this field.
Geothermal source heat pump (GSHP) systems as renewable energy systems are being more frequently installed as part of the zero-energy building drive. However, in South Korea, where a large amount of ...heating load can be required, maintaining high system performance by using only a GSHP is difficult owing to the gradual degradation of its thermal performance. The performance of a solar-assisted GSHP system was therefore experimentally analyzed and compared with a GSHP-only system. The results showed that the heating coefficient of performance of the GSHP-only operation was 5.4, while that of the solar-assisted GSHP operation was 7.0. In the case of the GSHP-only system, the maximum temperature of the heat pump water supply on the heat source side was initially 13.1 °C, but this rapidly decreased to 11.4 °C during operation. For the solar-assisted GSHP system, the temperature of the water supply to the heat source side of the heat pump was controlled at 15–20.9 °C, and the power consumption for system operation was reduced by about 20% compared with that for the GSHP-only system. Much higher temperatures could be supplied when solar heat is used instead of ground heat, as solar heat contributes to the performance improvement of the heat pump system.
Solar energy offers a promising renewable energy source; however, it is expensive to store electricity from photovoltaics (PV), the most widely deployed solar electricity technology. Solar thermal ...energy technologies can be paired with inexpensive thermal storage, but are more expensive overall. We have developed a solar receiver that combines PV and solar thermal systems to efficiently convert solar radiation to electricity (to be used immediately) and thermal energy (to be stored and converted to electricity on demand). This paper describes the Hybrid Electric And Thermal Solar (HEATS) receiver and models its performance. An idealized model predicts high solar-to-electricity efficiency (35.2%) with high dispatchability (44.2% of electricity from thermal energy) at an operating temperature of 775 K. Modeling using measured performance values for HEATS subcomponents predicts 26.8% efficiency and 81% dispatchability with silicon PV and 28.5% efficiency and 76% dispatchability with gallium arsenide PV, both operating at 700 K.
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•Hybrid solar receiver delivering both electricity and thermal energy proposed•Receiver enabled by transparent aerogel and spectrally selective light pipe•Modeling predicts >22% efficiency with current subcomponent properties•Efficiency greater than 35% predicted for improved subcomponents
PV and solar thermal systems are the main methods for solar energy conversion. PV cannot utilize the entire solar spectrum, and it is expensive to store the generated electricity. Solar thermal systems convert sunlight to electricity using thermal energy as an intermediary, allowing the use of inexpensive thermal storage, but are more expensive than PV overall. Hybrid systems that convert some of the solar spectrum to electricity directly using PV and the rest to thermal energy can achieve higher efficiency than PV or solar thermal systems while allowing the use of thermal storage. Here, we introduce a stacked hybrid receiver design enabled by transparent aerogel and a spectrally selective light pipe. Modeling predicts a 35% solar-to-electricity conversion efficiency with further subcomponent improvement and >26% efficiency with the best subcomponent properties reported to date. Further development of this receiver could thus yield a high-efficiency option for solar energy conversion.
We propose a Hybrid Electric And Thermal Solar (HEATS) receiver, which converts incident concentrated sunlight to both electricity and high-temperature thermal energy. Hybrid solar receivers that deliver electricity and thermal energy are promising because they can make better use of the entire solar spectrum than PV alone, and thermal energy can be stored inexpensively, allowing electricity generation when the solar resource is unavailable. The HEATS receiver is enabled by transparent silica aerogel and a spectrally selective light pipe.
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