Low Cost Solar Water Heater Research Articles

Designing and testing low-cost solar water heater using date palm fibers andstarch.

Solar water heaters are a type of renewable energy technology that converts solar energy into heat to warm water. Solar water heaters are becoming increasingly popular due to their eco-friendliness, cost-effectiveness, and low maintenance requirements. In this study, low-cost solar collectors were developed using date palm waste (dried leaves) as thermal insulation. Date palm waste is a readily available and abundant resource in many regions, and using it in solar collectors can help reduce waste and promote sustainability. Two solar collectors were fabricated using crushed date palm waste, with one collector using the waste alone and the other mixed with starch. Tests were conducted in accordance with the European standard EN 12975-2-2006 and modeled the thermal behavior of the collectors. The results obtained showed that the prototypes of solar collectors performed well and exhibited behavior comparable to that of a commercial solar collector, with a production cost up to three times less. The use of date palm waste as thermal insulation in solar collectors is an innovative approach that aligns with the principles of sustainability and environmental friendliness. Furthermore, it was found that the leveled heating cost (LCOH) and the simple payback period (SPP) were 0.952 US$ kWh-1 and 2.472 years for the prototype without starch and 0.926 US$ kWh-1 and 2.397 years for the prototype with starch.

PERFORMANCE OF LOW-COST SOLAR WATER HEATER

This study investigated the performance of a low-cost solar water heater (SWH). The SWH consists of a solar collector with a simple flat plate thermosiphon and water tank. The solar collector has, a glass cover, painted black on an aluminium absorber plate, water pipes and the sides insulated. During the testing process, the temperatures in the SWH were recorded at 1-second intervals by using Advantech Software DAQ Navi Data Logger, which is connected to a laptop via USB-4718, 8-Channel Thermocouple Input Module. The results that the efficiency of the solar collector ranged from 5% to 23%, with an average of 16% at water flow rate of 0.0019 kg/s. In addition, the time required by low-cost SWH to heat the water in a tank of 20 liters to reach its maximum temperature of 48.3°C is 8 hours 36 minutes

Design and performance testing of a bread box type low cost solar water heater for rural area

This paper deals with the design of integral passive low cost solar water heating system of “Bread Box” type for rural area. The designed capacity is 200lit and aims to cover the need of hot water at evening/night and morning for one to three people. This type of heater consists of horizontal cylindrical Mild-Steel tank painted flat black and is enclosed in a glazed (glass) insulated rectangular wooden box whose lid and front are opened as reflector (mercury-backed mirror) during the day and closed as insulation at night. In this research, bread box solar water heater was designed and constructed with local materials and then, this heater was tested. In this design, the diameter of collector-storage tank is 0.55 m, its length is 0.797 m and collector area is 1.377m2. The total glazing area of this heater is 1.859 m2 and box size is 1.341m x 0.884m x 0.76m.

Design approach of a density-driven solar water heater system

Energy conservation continues to play a crucial role in social and economic development. With the remarkable increase in oil prices and exploring solutions for the replacement of fossil fuels, an ecofriendly energy resource has become the priority among more and more people. Keeping the intension for reducing the global warming impact and looking for alternative clean source of energy, solar energy applications such as solar thermal systems, solar water heating and cooling are becoming energy-efficient designs. One of the widely used applications of solar energy is solar water heating systems. Low-cost solar water heaters can cover the domestic needs for water in the range of 100–200 l per day. Solar water heating systems are generally more efficient and advantageous in hot areas. However, the application of solar water heating is still a challenge in winter and sub-zero conditions, having low solar irradiance. In such conditions, solar water heating system cannot produce enough energy, which drives a need for evaluating system component design and improves its performance during low ambient conditions. In this study, detailed design methods for solar water heater components are discussed for cold regions like North Dakota, USA. The type of system chosen in this study is natural circulation-based solar water heating system. The study will also compare the experimental data with previously conducted numerical analysis.

Numerical and empirical evaluation of a novel building integrated collector storage solar water heater

Abstract Integrated collector storage is a long established simple low cost solar water heater configuration combining the solar collector with a storage tank into a single unit. Previous studies have shown the potential of integrated collector storage solar water heaters to significantly reduce domestic energy requirements for water heating, however challenges still remain to integrate them in roof/facades and ensure appropriate domestic hot water demand. In this article, a novel integrated collector storage solar water heaters is being investigated. The configuration and geometry proposed incorporates an embedded heating element to provide a self-contained domestic hot water system and consider roof integration restriction allowing the unit to be embedded within a structural insulated roofing panel system. The proposed system also utilizes an inlet diffuser designed to reduce the disruption to the stratification within the storage during and following draw-off. This article presents a Computational Fluid Dynamic analysis of internal flows and heat transfer regimes within this new collector configuration and compares its performance against previous developed prototypes using empirical testing. The increased aspect ratio of the new design was shown to significantly alter the heating and cooling characteristics of the collector, both gaining and loosing heat at a greater rate than the original prototype. The computational analysis showed that the collector charges effectively with some stratification. Higher draw-off rates however resulted in higher bulk water outlet temperatures, providing better energy delivery efficiency. The inlet diffuser was also shown to improve the thermal efficiency of the unit overall. The empirical testing shows the improvement in performance of this novel integrated collector storage solar water heaters against previous developed prototypes. The study highlights the need to review the effect of draw-off regime upon the performance of such systems in order to identify optimal regime and control strategy.

Development of Low-Cost Solar Water Heater Using Recycled Solid Waste for Domestic Hot Water Supply

This research is focused on the development of a low-cost solar water heater (SWH) system by utilizing solid waste material as part of system elements. Available technologies of the solar water heater systems, heat collectors and its components were reviewed and the best system combinations for low cost design were chosen. The passive-thermosiphon system have been chosen due to its simplicity and independency on external power as well as conventional pump. For the heat collector, flat plate type was identified as the most suitable collector for low cost design and suits with Malaysia climate. Detail study on the flat plate collector components found that the heat absorber is the main component that can significantly reduce the solar collector price if it is replaced with recycled solid waste material. Review on common solid wastes concluded that crushed glass is a non-metal material that has potential to either enhance or become the main heat absorber in solar collector. A collector prototype were then designed and fabricated based on crashed glass heat collector media. Thermal performance test were conducted for three configurations where configuration A (black painted aluminum absorber) used as benchmark, configuration B (crushed glass added partially) that use glass for improvement, and lastly configuration C (black colored crushed glass) that use colored glass as main absorber. Result for configuration B have shown a negative effect where the maximum collector efficiency is 26.8% lower than configuration A. Nevertheless, configuration C which use black crushed glass as main heat absorber shown a comparable maximum efficiency which is at 82.5% of the maximum efficiency for configuration A and furthermore have shown quite impressive increment of efficiency at the end of the experiment. Hence, black colored crushed glass is said to have quite a good potential as the heat absorber material and therefore turn out to be a new contender to other non-metal heat absorber such as plastic and rubber.

Effect of Dimples on Solar Concrete Plate Collectors and its Comparison with Other Domestic Water Heating Systems

Though solar water heater is an environment-friendly and a well-established effective method of heating water, yet it is not used on large scale in a country like India where abundant solar energy is available for most of the year. A large proportion of population prefers the use of electric geysers or stoves over solar water heaters as they have cheaper initial costs. Thus with an objective of low-cost solar collector water heater, an investigation is conducted on concrete as collector plate. In order to improve the efficiency of concrete plate collector, a serpentine tube is used instead of parallel tubes, with the addition of metal fibers in concrete mixture to improve its thermal conductivity and dimples are created on the serpentine tube to enhance heat flow from tube to water flowing through it. In order to calculate the exact effect of dimples on concrete plate collector, dimpled tube collector is compared with smooth tube collector. It is observed that dimples lead to an increase in outlet water temperature and improved efficiency for all water flow rates. Also in this paper, comparison of concrete plate collector with existing systems of domestic water heating for the bathing purpose is presented.

Design & Performance analysis of Portable Solar Water Heating System for Rural Areas: Himalayan Regions, India

Domestic Solar Water Heating systems (SWHs) have very low penetration specifically in the rural areas of Northern, Eastern and North-Eastern Himalayan States as the present SWHs are expensive, non-availability of good sun shine hours and weak manufacturing base & supply chain of this product in selected states. The paper is focused on field performance of developed low cost solar water heater for domestic applications for the rural areas of Himalayan regions. Field Performance data of Portable Solar Water Heating System (PSWHs) has been recorded during summer and winter months. It is observed that on solar Global Radiation of 3.28kWh/m 2 , the maximum temperature of hot water has reached 69 0 C at ambient temperature of 27 0 C within four to five hours showing a temperature difference of 42 0 C and maximum thermal efficiency of 74%.

Study of an efficient compact solar water heater

Solar passive water heaters are potential candidates for enhancing heat transfer. The purpose of this study was the design, construction, outdoor testing of a passive, simple and low-cost compact solar water heater (CSWH) system. As a new design, the black colored sands immersed into the water storage tank established the main portion of the collector absorber section. The water storage tank was manufactured from galvanized sheet of 0.0015m in thickness and the volume of 1.45×0.56×0.17m3. The effective area of the collector was 0.67m2. In all experiments results, the collector averaging daily efficiencies achieved higher than 70%. The performance of the novel CSWH system was simulated by using thermal network analysis. The simulation results showed that the collector absorber operated as a gray material. During one interest test, the peak temperature value of the stored water into the tank reached about 90°C.

Experimental study of integrated collector storage solar water heaters

Three Integrated Collector Storage Solar Water Heaters (ICSSWH) have been designed, constructed and experimentally studied in comparison to a Flat Plate Thermosiphonic Unit (FPTU). Each of the ICS experimental models consists of one cylindrical tank horizontally mounted in a stationary symmetrical Compound Parabolic Concentrating (CPC) reflector trough. The main objective is the design and construction of low cost solar water heaters with improved thermal performance and lower possible depths. The experimental models can be mounted on horizontal as well as on inclined roofs by adopting the lowest possible depth. The results show that these solar devices perform more than effectively all year long. This could contribute significantly on the development of ICS type solar water heaters.

Adoption of technology by the low-income population segment: The low-cost hot water heater case

The employment of means for efficient use of water and energy are being increasingly incentivized, in relation to the sustainability of buildings. In Brazil, there is much concern regarding the difficulty of getting low-income segments of the population to adopt energy-saving technologies. This study provides guidelines for the inclusion of manufactured, low-cost solar water heaters (LCSWH) in low-income housing in combination with environmental education of this segment of the population. Therefore, a group of dwellings located in a low-income community in Campinas SP, Brazil, was selected for installation of LCSWHs, which were assembled and installed by the study population itself, who also participated in environmental awareness workshops. Particularly apparent in the results obtained, was a tendency to reduce energy consumption by using the LCSWH, attributable in part to behavioral changes from environmental awareness; and that the planning, application or organized systematization of knowledge is feasible in low-income housing, provided it is not promoted solely by dependency culture, since the objective is to provide an instrument for self-discovery, mobilization and participation by the population.

The role and benefits of solar water heating in the energy demands of low-income dwellings in Brazil

In Brazil the widespread use of electrical showerheads for providing hot water for domestic consumption contributes to a load curve that peaks in the early evening, imposing a considerable burden to generation, transmission, and distribution utilities. On average, over 73% of Brazilian households use these 3–8 kW electrical resistance showerheads. In some of the more temperate climate regions in the south of the country, where most of the Brazilian population is concentrated, electrical showers are present in over 90% of residential buildings. For the residential consumer, while these high-power heating devices are the least-cost investment alternative, they lead to high running energy costs. Furthermore, due to their very low load factor (typically below 2%), each of these high-power showerheads results in considerably low return on the high investment costs in terms of infrastructure for the electricity sector. Particularly in low-income dwellings, electrical showerheads represent by far the highest electrical loads, resulting in a considerable component in the monthly energy bill. On the other hand, Brazil is one of the sunniest countries in the world, and solar water heating technologies have demonstrated large financial benefits and short payback times. Due to their comparatively higher initial investment costs, however, domestic solar water heaters are used mostly in higher income residences. In this work we present the potential of a low-cost version of the typical domestic solar water heating system for low-income dwellings, where the electrical resistance, which is normally installed inside the hot water tank, is replaced by a variable power electrical showerhead. This design avoids the use of electrical power as auxiliary heating for the whole of the boiler volume, since only the water which passes through the showerhead might be heated by the electrical resistance. This system configuration is a commercially available low-cost solar water heater option. A case-study is presented for a statistically representative group of low-income dwellings with solar water heating systems in Florianópolis – Brazil. Our results show that the economies obtained are considerable, both in terms of energy consumption (kW h) and peak demand (kW) reduction. When compared with higher income typical users of solar water heating technologies, these economies represent a relatively higher benefit, both for the low-income population, as well as for the utilities involved. Our results also show that the avoided power costs, a benefit for the distribution utility company, might be more substantial than the avoided energy costs, a benefit for the end user. In the energy constrained on-peak hours period, the utility company might benefit from being able to sell this energy to other higher paying tariff consumers.

Thermal performance of a trapezoidal-shaped solar collector/energy store

A simple, low-cost solar water heater has been developed for operation in Mediterranean Europe or regions of similar latitude (40–45° north). It takes the form of a trapezoidal-shaped water store in direct contact with an inclined flat-plate solar collector assembly. This cross-section induces thermal stratification in the water store, and provides sufficient energy storage to meet typical daily hot-water demand. Its thermal performance is critically dependent on the waterside convective heat-transfer coefficient on the backward-reclining collector plate; previously evaluated by Cruz et al. (Cruz JMS, Hammond GP, Reis AJPS. Buoyancy-driven convective heat exchange in a trapezoidal-shaped solar collector/thermal store. In: Proc. of the 5th ASME/JSME Joint Thermal Engineering Conf., San Diego, CA (ASME, New York), 1999, 9 pp). In the current design, the absorber plate inclination to the horizontal was fixed at 45° (close to the local latitude) in order to yield maximum solar gain over a typical year. The energy saving provided by the solar collector/thermal store demonstrator largely depends on the amount of thermal stratification within the trapezoidal storage cavity. This was evaluated via both computation and measurements of the temperature field. A thermal network analysis model was then used to assess the energy-saving potential of the composite system. It indicated that a 30–70% reduction in daily load could be obtained in contrast to direct, electrical or gas, heating: the smaller saving occurred at times of greatest use or hot-water take-off.

A simple low-cost solar water heater

SYNOPSIS The objective of this paper was to develop a domestic hot water system to satisfy Thai user requirements i.e. low cost (not over 2,000 baht/m2), warm water, and a simple design which could even be built by the user himself. This objective is accomplished by using commercial PVC pipes (1.5″). CPAC board was installed at the back acting, therefore, as absorber and storage for solar energy. Both covered and uncovered collectors were tested in two orientations: a west wall and a tilted, south-facing surface. The water capacity was limited to 35 litres. Water was withdrawn at different times of the day. Experiments were performed between March and June 2000. With the covered, mounted roof collector, temperatures as high as 72°C were obtained, whereas with the wall configuration, the temperature was about 65°C. To avoid damage to the PVC pipes caused by temperatures above 60°C, air was permitted to circulate between the cover and the pipes. It is concluded that the plastic covered CPAC-PVC pipe collector with appropriate openings at the top and bottom for air circulation seems to be very interesting. Due to the low-cost, simplicity of design and wide availability of materials used throughout the country, application of the design concept developed here is very promising. In addition, the installation of the solar water heater offers another extremely important benefit as it allows the heat gain through the building envelope to decrease.

98/03936 A low cost solar water heater suitable for rural, as well as urban, areas of Vietnam

The built-in-storage type of solar water heater will be suitable for rural as well as urban areas of Vietnam, in general, and the Hanoi region, in particular (mainly for domestic purposes). In this paper, a thermal model for optimisation of the design parameters and estimation of the effect of various parameters on the thermal performance of this solar water heater is presented. The paper also presents the numerical computations with the climatic conditions of the Hanoi region for three cases: (i) using a horizontal collector; (ii) using a sloped collector without reflector: and (iii) using a sloped collector with reflectors. On the basis of the numerical computations, conclusions for the application of this solar water heater in Vietnam have been made.

Design and fabrication of low cost solar water heaters

We designed two types of very low cost solar water heaters which do not need a water supply connection. The first one consisted of two plastic bowls, one inside the other with 5 cm thickness of insulation in between. A transparent plastic cover was tied around the smaller vessel. It was found that water placed inside the smaller vessel had its temperature raised by 18°C from the ambient temperature within four hours when the average insolation was about 600 kWh/m 2. The second one consisted of two earthen vessels in place of plastic bowls. The water temperature rise was 20°C under the same radiation. If either of the heaters was covered with cotton-wool insulation in the afternoon, the temperature remains 13°C above the ambient early next morning. The cost of the material was around US$ 4.50 for the plastic bowl heater while this is around US$ 3.50 for the earthen vessel water heater.

Performance and testing of a low cost solar water heater cum solar cooker

Performance of a novel device which can be used as a solar water heater during winter and a solar cooker during summer has been described. The device can provide approx. 50 1 of hot water at a temperature of 55–65°C in the evening which can be retained at 40–45°C until the next morning when tap water temperature is 15–20°C. The same device can also be used as a hot box solar cooker for cooking 4 kg of dry food per day. The overall efficiency of the device as a solar water heater is 62.6% and as a solar cooker is 23.8%. The payback period of the device shows that it is economical.