Solar Water Heating Technology Research Articles

Local non-similar solutions for EMHD nanofluid flow with radiation and variable heat flux along slandering stretching sheet

Nanofluids are the next-generation energy-transfer substrate due to their exceptional thermodynamic properties. The study of heat transfer on stretched surfaces is important due to its applications in industry, manufacturing, and medicine. The flow across a nonlinear stretched surface with different thicknesses is examined in this study to analyze the impacts of magnetic and electrical field, joule heating, viscous dissipation, and thermal radiation by considering Cu/water as nanofluid. To explore the physical characteristics, initially the mathematical model of the problem is evaluated and cataloged all of its features. Basic flow equations and fundamental rules were used to formulate the considered problem. The flow-controlling “partial differential equations” (PDEs) are transformed into a set of non-dimensional ordinary differential equations” (ODEs) via appropriate non-similar transformations. By utilizing the local non-similarity procedure operating bvp4c, the mathematical model is reconstructed. Physical representations of temperature as well as velocity profiles show how various emerging parameters interact with the flow. It is perceived that when the strength of the magnetic field grows, the velocity of nanoparticles decreases. However, as the electric field’s strength progresses and the velocity distribution does as well, the temperature profile for the nanomaterials rises. The radiation factor enhances the temperature field. The presence of time- and space-dependent characteristics for radiation, heat production increases as the fluid temperature rises. The authors investigate the procedure for replicating the dimensionless non-similar framework adopting the local non-similarity procedure. As per the author’s observations, there is currently no comparable study available in the literature for the flow model under consideration. This research holds significant potential for researchers engaged in the exploration of industrial applications of nanofluids, particularly within geophysical and geothermic domains, solar water heating technologies, biomedical applications, and other interdisciplinary fields.

Performance investigation of solar water heating system using flat-plate absorber integrated with thermal storage

The solar water heating (SWH) technology is a cost-effective method of harnessing solar energy and widely used in various countries worldwide. Adding thermal storage to the flat-plate collector increases the performance of the SWH system. It contributes to reduce energy loss to the top and increases energy transfer to the water. A novel composite material as thermal storage integrated with a flat-plate collector is constructed to make it effective in absorbing and storing heat energy. This work aims to investigate the performance of SWH system by integrating Al + Al2O3 composite to the flat-plate collector at the bottom as thermal storage. The performances of two models of absorber plates including a standard flat-plate collector and with Al + Al2O3 composite as thermal storage are investigated experimentally. The Al + Al2O3 composites were also tested and characterized to obtain their thermal properties. The results show that adding Al + Al2O3 composite as the thermal storage to the absorber plate contributes to increase absorption of solar irradiation, heat storage, and thermal efficiency of the collector. Then, the collector model with Al + Al2O3 composite as the thermal storage provides higher thermal efficiency than that of the standard model. For example, the thermal efficiency of the collector model with composite thermal storage of alumina 35% and aluminum 65% at angle variation increase of 5.1 % (0°), 7.5 % (10°), and 2.5 % (30°). Thermal properties of Al + Al2O3 composites as the thermal storage are also presented. It concludes that the greater percentage of alumina content, the lower value of the thermal properties of the composite obtained.

Overview of solar thermal technology development and applications in West Africa: Focus on hot water and its applications

Solar thermal technologies can help alleviate the sustainable energy access challenge in West Africa by offering complimentary solutions to reduce dependency on wood and fossil fuels. This paper provides a comprehensive regional overview of the water-based solar heating technology sector in West Africa in order to identify crucial factors that could boost a successful deployment of solar water heating systems in the region. Emphasis is placed on solar water heaters (SWHs), solar sorption refrigeration and solar heat for industrial process. The article summarizes the salient characteristics of widely used technological solutions and offers an understanding of the development and applications of solar water heating technology in the region. The review includes trends and research focusing on market, technologies, local manufacturing and policies, and shows that solar water heating potential remains scarcely exploited, with different status in different countries in the region. There are mostly thermosiphon systems with very few pumped systems. Industrial applications are practically inexistent, including concentrated solar heat. Finally, problems lying in the solar thermal sector in West Africa are analysed and measures for solving the problems are suggested.

Technical & financial feasibility assessment of heat pipe evacuated tube collector for water heating using Monte Carlo technique for buildings

The main objective of this work is to clear the economic condition of heat pipe based solar water heating technology in India. For this, a techno-economic analysis has been carried out which offers the facts for the investment in this sector. A computation model has been developed by the amalgamation of the Monte Carlo Technique (MCT) and Multi-energy/economic relations that take into consideration the risks and integrated uncertainties of different variables. The results reveal that LCWH and PP are found to be lowest for Zone-V and will require the least collector area. Since the highest solar radiation in Zone-V eventually reduces the ratio of annual energy demand to annual solar radiation. Thus Zone-V is the most favorable place for the installation of the solar water heater. The mean values of LCWH, NPV, and PP are found to be 5.14 INR/kWh, 663788.48 INR, and 5.84 years respectively. However, values of LCWH, NPV, and PP through optimization were found to be lesser by 25–33%, higher by 9–28%, and lower by 37–47% respectively.The MCT is efficient to defeat discrepancies in the results of conventional techniques by taking into consideration the range of states according to their probability to offer more accurate forecasts.

Global Challenges of Current Building-Integrated Solar Water Heating Technologies and Its Prospects: A Comprehensive Review

Among the renewable energy resources, solar thermal is one of the technologies that significantly contribute to energy supply and reduce global greenhouse gas (GHG) emissions. Solar water heating (SWH) contributes a large proportion of the global solar thermal capacity, with 63% installation for domestic hot water (DHW) systems, 28% for large DHW systems, and the remaining 9% for other applications such as swimming pools heating, solar district heating, and space heating. Still, now, there are many challenges and limitations of those SWH technologies. The present work reviews the current challenges faced in the domestic SWH industry globally. The integration of thermal energy storage (TES) systems for better collector’s radiation absorption and overall performance are also highlighted. Many countries worldwide seem to face similar challenges within the SWH technologies and industry. It is proven that these challenges and limitations can hinder the global capacity of solar thermal utilization.

Opportunities for solar thermal systems across dairy, agricultural, hotel & automobile industries

Solar thermal heating or solar water heating technology, despite having low applications, provide exceptionally higher efficiency than photovoltaic cells. If this technology is innovated with advancing research then many industrial sectors like dairy, agriculture, hotel, automobile, etcetera, would be beneficial after adopting and utilizing it. Developed and developing countries are starting to notice its importance due to declining climatic conditions and increasing global warming. Here, in this paper, the opportunities of solar water heating or solar thermal technology across the dairy and agricultural industry, as per the latest data, are discussed. Various methods and processes employing solar thermal heating technology are also explained in the paper. Furthermore, case studies in the hotel industry and automobile sector are also depicted.

Comparison of three solar water heaters technologies through a full-scale experimental station

The aim of the solar water heater designed for Tahala grid project, is to provide renewable energy to the residents of Tahala village in southern of Morocco, our contribution as LERED* laboratory to this project consists of the creation of a novel solar water heater, with a long lifetime, high efficiency, reliability and quality, that uses solar concentration instead of direct exposition in the hope of reaching high temperatures even during cold weather and the winter season. In order to evaluate the performances of this new solar water heater, it was necessary to build a full-scale solar water heater test bench station, which allows to monitor the thermal station remotely, in order to start new experiments, measure various parameters such as cumulated thermal energy, the maximum reached temperature, efficiency, and so on, in order to compare the performances of each solar water heating technology in various weather conditions. In this study, we choose to test and compare three solar water heater technologies: water-in-glass evacuated tube collectors, selective surface flat-plate collectors, and the novel design that consists of a Fresnel mirrors concentrator with a water-in-glass evacuated tube collector with a dual sun tracking system. The result of experiments shows that under normal weather conditions, the Fresnel mirrors concentrator efficiency reached 48%, followed by the evacuated tube collector that have an efficiency of 42.3 %, and then come at the last position the flat-plate collector with an efficiency 36.3%.

Decoupling the Monitoring of Solar Water Heaters and their Usage Profiles

South Africa is the most technologically advanced nation in Africa. However, the country is plagued with constant load shedding. The country receives about 2500 sunshine hours annually, with daily average irradiation levels of 4.5–6.5 kWh/m2. Despite these potentials, the use of electricity for domestic water heating is still prevalent in the country. The mass rollout of solar water heating (SWH) technologies in the low-cost housing sector across the country were met with massive failures. This study aims to assess the energy yield of a passive flat plate and an evacuated tube solar water heating system by evaluating the performance of these systems to address the energy crisis in South Africa. The flat plate (FP) and evacuated tube (ET) solar water heating systems were monitored for four days, characterised by varying sky conditions through instantaneous data measurement at 5 s. The parameters measured were water temperature, ambient temperature, irradiance at the plane of array, relative humidity, wind speed and direction. The results obtained show that a maximum irradiance of 1050 W/m2 was obtained on a clear day and corresponded to a hot water temperature of about 58 °C and 65 °C for the FP and ET, respectively. However, a cloudy day with a maximum irradiance of 400 W/m2 produced about 22 °C and 29 °C of hot water for the FP and ET, respectively. The results obtained in this study will guide stakeholders in the renewable energy sector towards employing SWH systems to replace or augment the electric geyser. Solar water heaters (SWH) can be used in the low-cost housing sector to provide hot water. Hence, the assessments in this study offer essential information for the deployment of these systems to reduce demand on the ailing South African electricity utility, Eskom, and mitigate climate change.

Fault Analysis of Solar Thermal Systems in Bhutan

The Royal Government of Bhutan has accorded the highest priority towards diversifying the energy-mix through the promotion of renewable energy technologies. There is a national target to generate 3 MW equivalent of energy from the installation of solar thermal systems alone. However, little investment and priority are given for development of solar thermal applications. Some of the present existing solar water heating (SWH) systems are exhibiting faults which leads to low consumer confidence in SWH technology due to the non-functioning of previous installations which is very detrimental in this introductory stage. This study aims to identify problems of existing SWH systems through field surveys and develop a draft guideline to avoid faults in the future. To analyse the problems with existing SWH systems in Bhutan, the first phase of the study consists of collecting secondary information and opinion from the relevant government sector, local installing companies and end-users. The information on the manufacturer’s products, policy barriers, markets and consumer challenges is also collected. Base on this information, findings on the limitation of existing policy instrument and gap in demand and supply side is described. The second phase of the study comprises field visits to existing SWH system sites. The field surveys of twelve representative existing SWH systems are analyzed. Out of twelve sites, eight SWH systems had critical faults which causes major failure of the system and the other four sites had minor faults. To analyse the faults of existing SWH systems, faults are classified into design faults, plumbing circuit faults, solar collector faults, absorber faults, installation faults and user behavior faults. The major faults which lead to the failure of the existing SWH system are plumbing failure, condensation inside the collector and absorber tube leakage. The causes and solutions of the faults are discussed.

Energetic, economic and environmental analysis of domestic solar water heating systems under the African continent

Given the abundance of solar irradiation in Africa, different types of Solar Water Heating technologies can offer practical and reasonable solutions that are valuable for African people and their environment. However, these technologies' impacts were not quantified, and lack of studies could be in part attributed to the weak implementation of solar water heating systems on most countries in Africa. The aim of this paper is first, a model was developed and validated to investigate and analyze the energy performances of the two most domestic used technologies in the African continent: the flat plate collectors and the evacuated tube collectors. Next, the economic and environmental aspects of these systems are also presented. The study was carried out for 43 countries divided in 5 regions: North Africa, West Africa, Central Africa, East Africa and Southern Africa. The energy analysis, in terms of solar fraction, shows that the solar production of domestic hot water varies between 25 and 88% for the evacuated tube and between 10 and 60% for the flat plat collector and this according to the 5 regions mentioned above. Based on the Net present worth, the Benefit–Cost Ratio and the Discounted payback period, the economic analysis shows that these two technologies are beneficial for 16 of the 43 countries studied. That is due to the abundance of other energy resources in the remaining countries.

Ign and Control Analysis Of An Automatic Active Domestic Solar Water Heating System

Solar water heating technology is one of the cost-effective ways of heating water in residential and public buildings. This study presents the design technique for an automatic active domestic solar water heating system (ADSWHS) to meet the hot water demand for a residence in Wum (10.43°E, 6.23° N) with a daily hot water demand of 500 litres at 70 o C, using flat plate solar collectors and an arduino microcontroller. The solar data used in this analysis were obtained from Photovoltaic Geographical Information System (PVGIS) and the method used is the active direct roof mounted solar water heating. The system design process consist of evaluating the optimum collector tilt angle, the thermal analysis of the flat plate collector and hot water storage tank and finally modelling a low cost automatic controller for the system using an Arduino in the Proteus software. The optimum annual average solar radiation on the tilted solar collector was obtained following the calculation of the conversion ratios of the direct , diffuse and reflected radiations. At annual time scale, the appropriate tilt angle (I²) that maximizes the collection of solar energy was 11 o and the corresponding optimum average irradiance of 432 W/m 2 wasobtained. The analytical results presented for the performance of the heater indicate that the system operates at an annual thermal efficiency of 55.49%. The control system simulation results indicate that the system uses 4.5kWh and 2.075kWh of energy to run the pump and the auxiliary heater respectively and produces 26.187kWh of energy to heat up the cold water from 25 o C to 70 o C for a single day.

Novel method of thermal behavior prediction of evacuated tube solar collector

Heat pipe evacuated tube solar collectors (HPETCs) are a type of solar collectors with appealing characteristics for the application in solar water heating (SWH) technologies. In order to better understand the heat transfer phenomena in HPETCs and improve their efficiency, there is a need for a fast and robust numerical tool. Due to the complexity of the heat transfer processes involved in modeling a collector’s performance, direct numerical analysis solutions (DNS) are computationally cumbersome. Recent studies have shown that resistance network (RN) models are suitable tools for studying the performance and thermal behavior of HPETCs. In this work, a novel method of resistance network based proper orthogonal decomposition (RNPOD) is presented which can not only consider the geographical and meteorological characteristics of the ambient surroundings, but also take into account the peripheral temperature distribution of a single HPETCs. Once the temperatures at each instance in time have been calculated, a POD method is used to predict the thermal behavior of the collector with desired temporal accuracy. The obtained results of this study are cross-validated with the previous experimental work of the authors, illustrating that the model is able to predict the peripheral temperature distribution with a maximum error of 10%.

Collector characterisation and heat loss tests on a novel batch solar water heater with CPC reflector for households

ABSTRACTThis solar water-heating unit is an integration of the older concept of batch water heating with the modern trends in solar water-heating technologies i.e. incorporating a concentrator in the design. The concentrator used is the compound parabolic type (CPC) which is a non-imaging device having wider acceptance angle (64°) and supported on a wooden cradle, which comprises the two arms of the parabola. To suppress the heat loss, an air gap has been introduced in the arms of the CPC. The collector is a single larger diameter drum which serves both as an absorber and storage unit positioned at the focus of CPC. The parametric study of the model showed the thermal efficiency of the collector as high as 38% and maximum water temperature attained was 53°C. Heat loss tests performed on the collector on a 24-hr cycle period showed good long time performance estimates. The response time of collector computed and performance characteristic curve plotted to predict system response under any given conditions of solar insolation and ambient temperature.

The governance of urban energy transitions: A comparative study of solar water heating systems in two Chinese cities

This paper examines how urban energy transitions are unfolding in China, in relation to the deployment of solar water heating (SWH) systems in two Chinese cities, Rizhao and Shenzhen. Cities play a significant role in the energy transition in China. Scholarly efforts have looked into the translation of top-down visions into locally actionable policy. This article contributes to this body of research with an analysis of the urban governance of urban energy transitions in China, and how low carbon technologies are deployed in particular urban contexts. The comparative analysis of Rizhao and Shenzhen suggests that specific socio-spatial arrangements shape the evolutionary trajectories of urban energy transitions of SWH systems in both cities. In the case of Rizhao, policy approaches have been erratic. Nevertheless, governmental and civil society actors have worked to forge alignment among political visions, built environment constraints, and social practices. The proximity of an industrial cluster supporting SWH technology and the early uptake of this technology by households are two key factors that explain the rapid spread of SWH systems in Rizhao. In Shenzhen, the local government has promoted SWH systems through regulation and incentives in a top-down and coordinated manner. These programmes have been, however, abandoned, after they did not deliver the expected results. The two contrasting cases suggest that the urban energy transition in China is the result of the coordinated actions of multiple actors, and success depends on the fit between technologies and the urban development contexts, rather than on aggressive government-sponsored actions.

Comparative Analysis of Exergy and Efficiency for Stratified Thermal Storage Tank with Solar Flat Plate and Evacuated Tube Collectors

In recent years, solar water heating technology has got the major importance in water heating applications. For the efficient and effective working of solar water heaters, storage of the hot water is the main issue in this water heating technologies. This paper mainly presents the exergy and efficiency comparison between the solar flat plate water heater and evacuated tube water heater. A five level stratified thermal storage tank is designed and developed for this analysis. At each level of the tank, temperature of the water is collected for each one hour interval from 9:00 to 16:00 hours in both cases and the overall exergy and efficiency of the two water heaters were calculated. The average efficiency of all the levels for flat plate and evacuated tube collectors are 7.91% and 8.20% respectively. The overall system efficiency is obtained as 39.54% for flat plate and 41.00% for evacuated tube solar collector. At each level exergy is calculate for both systems and the average exergy of all the levels for flat plate collector is 4.243 kW and for evacuated tube solar collector is 4.371 kW.

What makes renewable energy successful in China? The case of the Shandong province solar water heater innovation system

The Chinese province of Shandong, and more particularly its cities Dezhou, Jinan and Rizhao, have established an international reputation of being hotbeds for solar water heating (SWH) technology development and dissemination. The article aims to unveil the evolution of this innovative environment by applying the Functions of Innovation Systems (FIS) approach to the Chinese province of Shandong. It examines the actors, institutions and policy instruments that shape Shandong's innovation system for SWH, the dominant drivers and barriers during the evolution of the TIS and also assesses the applicability of the IS approach to China. It appears that the presence of influential interest organizations and proactive support from local governments have acted as strong drivers for the emergence of Shandong's innovation system for SWHs. On the other hand, the lack of adequate personnel and an overreliance on government policies act as main barriers. With regard to the Chinese specificities potentially detracting from the relevance of applying IS theory to China, we did not find that the central government acted as an initiator of innovation nor that state-owned enterprises had dominant positions in the market. In this innovative industry the impetus for development came from the bottom up and from private corporations.

An Overview of Evacuated Solar WaterHeating System

One of the most widely known solar thermal applications is solar water heating. In terms of installation expenditures and energy cost over the total life of the system, solar water heating technology has proven to be cost efficient for several domestic and industrial applications. Technological practicability of these systems has long been recognized and is presently employed in commercial sectors of many countries. This paper presents an overview of various types of solar assisted water heating systems and their market potential. Residential solar water heating is a promising age old technology, which has been evolved and developed both in the range and quality as a successful packaged market–product. The first part of this paper analyzes the performances along with how unique they are of different types of solar water heating systems and the later part of the paper covers its economic aspects.

Solar Energy “In A New Light” at Boeing: Solar Heated Water for Paint Booth Operation At Boeing's Salt Lake City, Utah, Factory

ABSTRACTIn developing a new paint booth design for use in application and cure of coatings on aircraft assemblies at its Salt Lake City, Utah, manufacturing facilities, Boeing applied renewable energy through the use of evacuated tube solar water heating technology to offset natural gas consumption and reduce greenhouse gasses. This also helped achieve Leadership in Energy and Environmental Design (LEED) Silver certification from the U.S. Green Building Council [1] for the 30,000-square-foot building.It's challenging to achieve LEED certification for an office building, but it's really challenging to make a paint facility LEED-certified. To do so the building was designed to include numerous large windows, a rainwater collection system; recycled and salvaged building materials and enhanced environmental controls. But what really makes the building stand out are the 3,600 rooftop-mounted solar tubes that provide heating for a portion of the paint preparation, curing and drying operations. Located on the ro...

The Application Study in Solar Energy Technology for Highway Service Area: A Case Study of West Lushan Highway Low-Carbon Service Area in China

A lot of research works have been made concerning highway service area or solar technology and acquired great achievements. However, unfortunately, few works have been made combining the two topics together of highway service areas and solar energy saving to make a systemic research on solar technology application for highway service area. In this paper, taking West Lushan highway low-carbon service area in Jiangxi Province of China as the case study, the advantages, technical principles, and application methods of solar energy technology for highway service area including solar photoelectric technology and solar water heating technology were discussed based on the analysis of characteristics of highway low-carbon service area; the system types, operation mode, and installing tilt angle of the two kinds of solar systems suitable for highway service areas were confirmed. It was proved that the reduction of the cost by electricity savings of solar system was huge. Taking the investment of the solar systems into account, the payback period of solar photoelectric systems and solar water heating systems was calculated. The economic effect of the solar systems in West Lushan highway service area during the effective operation periods was also calculated and proved very considerable.

In–Situ Measurements of the Performance of ermosyphon Solar Water Heating Systems in Libya

This paper reports on a project carried out by the Centre for Solar Energy Research and Studies (CSERS) to familiarise Libyan people with solar water heating technologies. Around 100 solar water heaters have been installed in the domestic sector and selected systems were equipped with monitoring instruments required to evaluate thermal performance. The paper presents the results of data collected over a one year period from a system installed in a family residence situated in a village located 90 km south of Tripoli(Libyan capital). The results showed that the system solar fraction was 55.8% of the average amount of daily hot water withdrawn (144 litres) at an average withdrawal temperature of 46.6 °C. T e total energy withdrawn during the whole year was 1557 kWh. It is concluded that such a system is not adequate in terms of cost-effectiveness for the current installed situation. It is recommended that the annual solar fraction for any solar water heating system should be over 70% in order to achieve cost-effectiveness and to help widespread take-up of this technology.