scholarly journals Decoupling the Monitoring of Solar Water Heaters and their Usage Profiles

Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3186
Author(s):  
Julian C. Nwodo ◽  
Ochuko K. Overen ◽  
Edson L. Meyer

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.

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
Mohammad Abdunnabi ◽  
Ibrahim Rohuma ◽  
Essam Endya ◽  
Esmaeel Belal

This review paper aims to provide a comprehensive review of the history and the best practices of solar water heaters in Libya. Although, Libya is blessed with high solar potential, there is no wide-spread implementation of this technology due to many reasons such as: the cheap price of both electricity and electric water heaters, lack of clear and systematic policy, and lack of environmental awareness. The Center for Solar Energy Research and Studies (CSERS) has given attention to this technology since its establishment in 1978, and the solar water heating system field test project is one of the research projects in the Center. The paper has shown that there was no attention paid to this technology and even to renewable energy in general in the previous years. However, preliminary information clearly shows the importance of continuing research in this field. Numerous valuable information on solar water heating systems from literature were dedicated and made available for researchers and decision makers. The studies conducted in this field for Libya are arranged in this review on the bases of the topic studied: performance evaluation, optimization, on-site measurements and policies and strategies. One of the most important results retrieved from these studies show that the daily quantity of hot water withdrawn per capita at 45 °C is estimated around 60 liters. The estimated annual amount of energy consumed for water heating per person is 510 kWh. For average Libyan family of six persons, the annual amount of energy consumed per dwelling is estimated about 3060 kWh. The review also presented the history of solar water heaters implementation, manufacturing and testing facilities for quality control in Libya. The study calls upon the Libyan decision makers to take their responsibility and put an urgent action plan to help the wide-spread implementation of solar water heaters in the residential, services and industrial sectors. Such a plan will surely alleviate the ever increasing demand for electricity, save fossil fuel reserves and mitigate GHG emissions.


1997 ◽  
Vol 119 (4) ◽  
pp. 265-272 ◽  
Author(s):  
A. H. Fanney ◽  
B. P. Dougherty ◽  
K. P. Kramp

Energy consumed for water heating accounts for approximately 17.9 EJ of the energy consumed by residential and commercial buildings. Although there are over 90 million water heaters currently in use within the United States (Zogg and Barbour, 1996), durability and installation issues as well as initial cost have limited the sales of solar water heaters to less than 1 million units. Durability issues have included freeze and fluid leakage problems, failure of pumps and their associated controllers, the loss of heat transfer fluids under stagnation conditions, and heat exchanger fouling. The installation of solar water heating systems has often proved difficult, requiring roof penetrations for the piping that transports fluid to and from the solar collectors. Fanney and Dougherty have recently proposed and patented a solar water heating system that eliminates the durability and installation problems associated with current solar water heating systems. The system employs photovoltaic modules to generate electrical energy which is dissipated in multiple electric heating elements. A microprocessor controller is used to match the electrical resistance of the load to the operating characteristics of the photovoltaic modules. Although currently more expensive than existing solar hot water systems, photovoltaic solar water heaters offer the promise of being less expensive than solar thermal systems within the next decade. To date, photovoltaic solar water heating systems have been installed at the National Institute of Standards and Technology in Gaithersburg, MD and the Florida Solar Energy Center in Cocoa, FL. This paper will review the technology employed, describe the two photovoltaic solar water heating systems, and present measured performance data.


2018 ◽  
Vol 37 (3) ◽  
pp. 1147-1161 ◽  
Author(s):  
Esdras Nshimyumuremyi ◽  
Wang Junqi

Solar water heating is a technology of capturing the energy from the sun's radiation for the purpose of raising the temperature of water from water supply temperature to the desired higher temperature depending on the use. There are many views and discussions on the questions of thermal efficiency of solar water heaters and their associated cost, especially different customers/users want to replace their existing conventional water heating energy by solar water heating systems. In this present paper, a deep investigation has been accomplished to determine thermal efficiency and cost analysis of solar water heater made in Rwanda. During manufacturing of solar water heater, the collector was the main part to emphasize on. The high efficiency of the system was achieved by replacing galvanized iron sheet by aluminum sheet slotted and black painted as an absorber plate. The ambient temperature and average solar radiation of the three sites where solar water heaters are installed were investigated. The used materials, specifications and sizing were discussed in this paper.


Green ◽  
2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Brian Norton

AbstractSolar water heating can be considered to be an established mature technology. The achievement of this status is the outcome of over a century of system development that culminated with a flourish of innovation in the last thirty years. Drivers for research and development have been achieving economic viability by devising systems that, for specific applications in particular climate contexts produced more hot water per unit cost. Reductions in both initial capital and installation costs have been achieved as well as in those associated with subsequent operation and maintenance. Research on solar water heating is discussed with the emphasis on overall systems though some key aspects of component development are also outlined. A comprehensive taxonomy is presented of the generic types of solar water heater that have emerged and their features, characteristics and performance are discussed.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Reza Alayi ◽  
Nima Khalilpoor ◽  
Saeid Heshmati ◽  
Atabak Najafi ◽  
Alibek Issakhov

Due to the reduction of fossil resources, the replacement of renewable energy sources such as solar energy has become mandatory. Solar energy does not contain pollution and widely available in all parts of the world, especially in warm regions. Our country (IRAN) is geographically located in a hot and dry region, and with more than 280 sunny days per year, one of the nonpower applications of solar energy is heating space and water consumption of the building using solar thermal energy. Solar water heaters can be used to heat the water used in buildings, which is the main purpose of this study. Water heating consumes an average of 20% to 30% of the total energy consumption in the residential building. Therefore, using solar water heaters annually can provide 70% of the energy needed for water heating. The system designed in this research is able to provide 75% of the hot water consumption needs. If an auxiliary heat source is used next to this system, all hot water needs of the building can be met throughout the year. In this case, as much as 237.3 kWh, energy will be saved from fossil energy sources.


1991 ◽  
Vol 113 (2) ◽  
pp. 94-101
Author(s):  
Michael Ewert ◽  
John E. Hoffner ◽  
David Panico

The City of Austin is studying the impact of solar water heaters on summer peak electric demand. One passive and two active solar water heating systems were installed on city-owned commercial buildings which had electric water heaters in 1985 and have been monitored for two years. A method has been developed to determine the peak demand reduction attributable to the solar systems. Results show that solar water heating systems are capable of large demand reductions as long as there is a large hot water demand to displace. The average noncoincident demand reduction (during the water heater’s peak output) ranged from 0.8 to 5.8 kilowatts per system. However, the coincident demand reduction during the utility peak demand period was 0.3 to 0.8 kilowatts per system. Thus, a critical factor when assessing the benefit to the electric utility is the time of hot water demand.


2021 ◽  
Vol 2 (1) ◽  
Author(s):  
M.J.R Abdunnabi ◽  
M. A Musa

Solar water heaters have been in use for decades in many countries in the world that have less favorable climatic conditions for solar energy as compared with Libya. However, still there is no usage of such technologies in the country. This could be attributed to many factors including, among others, lack of clear policy and/or serious plans to establish such technology, cheap prices of conventional energy, and lack of environmental awareness.The Center for Solar Energy Research and Studies (CSERS) of Libya has developed an excellent research and development program on national scale for domestic solar water heating systems. The national program started in the early 1990’s aiming at increasing public awareness. The program utilizes different ways such as pilot projects, studies, workshops, and reports to convince people and decision- makers of Libya about this subject and its benefits.This paper attempts to suggest a strategic plan (win-win situation between government and people) for encouraging and helping wide spread (replacement) of solar water heaters nationwide based on economic and environmental pointers in favour of the replacement.The suggested strategic plan is to provide 25% of existing houses in 2013 with solar water heating systems by 2022, with governmental subsidy of up to 65% of the system cost. The study has shown that every L.D. paid by the government will return with at least 2 L.D. after 10 years of investment without considering the money saved from the fuel savings, power plant installations to fulfill the demand, and the environmental benefits.


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