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Currently, the electrical power shortage in Iraq and the existence of programmed stoppage mechanism at the Ministry of Electricity does adversely affects the work of information systems. Videoconferencing is uninterruptable systems which is one of the most important activities in information technology and e-learning systems. The study aims to desi...
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... to the discovery of this first battery, several other batteries were unearthed in Iraq, all of which dated from the Parthian occupation between 248 BCE and 226 CE. In the 1970s, German Egyptologist Arne Eggebrecht built a replica of the Baghdad battery (see Figure 4), and filled it with grape juice, which he deduced ancient Sumerians might have used as an electrolyte. The replica generated 0.87 V of electric potential. ...
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Interactive e-learning is a distance learning method that involves information technology, electronic system or computer as one means of learning system used for teaching and learning process that is implemented without having face to face directly between teacher and student. A strong dependence on emerging technologies greatly influences the way...
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... The capacity of photovoltaic panels is calculated according to the equation (1) as follow [37], taking in consideration that the number of solar hours in Syria is 5 hours (fig 1) The capacity of the inverter must be greater than the required load by (20-30)% [37] [38], and could be calculated as in equation (2) The capacity of the batteries is expressed in Ampere-hour (Ah). Various factors are taken into consideration while choosing the size of the batteries or battery bank, including the total load, discharge depth, and the battery nominal voltage. ...
This study presents pre-cooling technology using a solar photovoltaic energy system where the
increasing in air-conditioning demand during summer results in a rise in the amount of electrical
energy consumed from the electric network, as well as an increase in electricity bills. Air conditioners
are operated in governmental facilities during official working hours, at the time of the peak demand
for electricity, when electric costs are the highest. In order to shift the cooling demand out of the peak
period into a lower electric cost period, reducing the energy consumption of the building and the value
of the electricity bills, this study was conducted on the technology of pre-cooling using solar
photovoltaic energy system.
The Engineers Association Branch in Latakia was conducted as a case study. The results showed that
applying the Photovoltaic (PV) pre-cooling system led to a significant decrease in the cooling demand
during thek hours, and reduces the daily consumption of the electric power from the electric system,
as the demand was decreased from 85 kWh to 21,250 kWh. Besides, the value of the electricity bills
was decreased by 83%. Pre-cooling lowered the PV system capacity that was needed to operate the
building's air conditioning equipment by 50%. A reduction of 42.5 kg of CO2 emissions per day could
be achieved using PV-pre-cooling system
... The energy consumed by each load and the duration of its daily operation (in hours) will be measured. The amount of loads and the number of hours of operation vary from device to another [65]. Energy consumption per load is calculated by units of watt-hour by multiplying the amount of energy consumption per load by the number of hours operating as shown in equation . ...
... The impact of climate variables at different site locations is taken into consideration by the power generation factor in equation [65]. The most popular mathematical relationship for calculating the total size of PV modules by using mean daily insolation during peak-sun hours to run the required load is [64][65][66][67][68]: ...
... The impact of climate variables at different site locations is taken into consideration by the power generation factor in equation [65]. The most popular mathematical relationship for calculating the total size of PV modules by using mean daily insolation during peak-sun hours to run the required load is [64][65][66][67][68]: ...
... The voltage rating of the charge controller must match with the system voltage; and its current rating must exceed the maximum input current expected from the array approximately evaluated from (Alshemmary et al., 2013;Saleh et al., 2015): ...
There is a desperate need for high-quality, affordable, and reliable lighting systems at sites where the electricity grid is either non-existent or unstable for applications such as security lighting. Many systems installed in Nigeria are failing due to poor design or wrong sizing of the components. This paper gives a detailed design and analysis of Stand-alone Solar Street Lighting Systems taking six selected locations in Nigeria as cases of the study for comparison. The variations of solar radiation and night lengths were considered. The monthly average solar radiation data were based on 22 years of monthly average insolation figures obtained from the National Aeronautics Space Administration (NASA). A single LED lamp rated 12V, 40W DC operating from dusk to dawn was used for the design. The results show that the length of nights varies seasonally with maximum values in December and minimum values in June for all the locations with places closest to the equator having the least variation. Components requirement indicates that a piece of 12V, 100Ah battery, and a piece of 12V, 20A charge controller will suffice for all the locations. The difference is based on solar array requirement in which the results show that 2 pieces of 120Wp solar panel connected in parallel will be adequate for PortHarcourt, and Benin-City; 2 pieces of 100Wp for Ibadan, and Makurdi; and 2 pieces of 80Wp for Kano and Maiduguri. The difference in the array requirement was based on the solar radiation available in the location, for those having higher radiation require less solar array and vice versa.
... proper and economical design [20]- [23]. Monitoring the performance and loss factors of PV systems is important to assess overall efficiency and to enhance productivity [24], thus a successful implementation of solar PV systems involves knowledge on their operational performance under varying climatic condition [25]. ...
This article is the product of the investigation "Development of a photovoltaic pilot system for performance assessment of isolated systems in the Renewable Energy Laboratory at UNAB" developed at the Universidad Autónoma de Bucaramanga (UNAB) in 2019, considering off-grid solar home systems (SHS) are a feasible alternative in rural remote areas, where access to electric power is limited due to their power grid lack. The objective is to develop a PV test system for off-grid solar home system (SHS) performance assessment. For the development, a case study is analyzed based on the behavior of a user's daily demand in Hato Corozal, Casanare. Design aspects of the system are also elaborated. Key performance parameters identified to be monitored are solar irradiance, power generation, energy consumption and battery charge status. Two scenarios of daily demand behavior are analyzed to evaluate the influence of load shifting on the performance of the system. The applied design criteria were validated obtaining that the sized system satisfied the energy requirement without a battery’s depth of discharge (DOD) deeper than specified, showing the capacity of the system to make studies in longer periods with the possibility of generating different demand behavior scenarios. The designed system presents a performance ratio of 0,77 when a daily consumption is considered, while when shifting loads to coincide them with the higher irradiance the PR was 0,95. In both cases, the SoC was higher than 79%, maintaining a DOD of the battery bank according to the specified in the sizing. The system presents excess energy that can be used by expanding the capacity of the battery bank. Findings suggest that a higher performance ratio is obtained when coinciding consumption peaks with the hours of higher solar radiation.
... The actual power output of a solar panel depended on peak power rating, and operating factor, the power used at the end user is less due to lower combined efficiency of the solar PV system [2,5]. The amount of energy storage is important to use the energy from the loads when sunlight is absent. ...
... The solar photovoltaic systems required rechargeable batteries. There are various commonly available rechargeable batteries but the batteries with high depth of discharge are used in solar photovoltaic systems [5,6]. ...
... Energy payback period is a commonly used indicator in the life cycle assessment of photovoltaic solar systems to justify the initial use of energy to produce components of photovoltaic systems, and the time of energy recovery is the proportion of total embodied energy incurred in the manufacture of photovoltaic systems and the annual energy produced by photovoltaic systems [2,6]. In order to calculate the daily consumption power of all the loads with an hourly time step was constructed, this gave a good understanding of how often the loads are used during the two different periods of the days [3,5]. ...
The aim of this work is to present of a specialist design of solar PV system to
provide load at (8a.m. to 2p.m.) as daily energy consumption, by expanding in solar panels numbers with reducing battery numbers, consider the cost of batteries proportionally to solar panels cost. The specialist design depended on load consumption (6) hours between (8 a.m. – 2 p.m.) at sunshine day to supply power to load directly from the PV system generation with little contribution battery energy. The results show specialist design can be useful for this situation of covering load consumption in (6 hours) band benefit to used PV system to reduce the solar PV systems cost, was the performance analysis of this system from April to October.
... Abdelkader et al. (2010) reported that the monocrystalline PV cells were more efficient compared to the polycrystalline and this is in agreement with results obtained by several authors (Taşçıoğlu et al., 2016;Husain et al., 2018) a. We used Equation 4 to determine the solar PV panel wattage size (AlShemmary et al., 2019): ...
Maize is the main food crop that meets the nutritional needs of both humans and livestock in the sub-Saharan African region. Maize crop has in the recent past been threatened by the fall armyworm (Spodoptera frugiperda, J.E Smith) which has caused considerable maize yield losses in the region. Controlling this pest requires knowledge on the time, location and extent of infestation. In addition, the insect pest's abundance and environmental conditions should be predicted as early as possible for integrated pest management to be effective. Consequently, a fall armyworm pheromone trap was deployed as a monitoring tool in the present study. The trap inspection is currently carried out manually every week. The purpose of this paper is to bring automation to the trap. We modify the trap and integrate Internet of Things technologies which include a Raspberry Pi 3 Model B+ microcomputer , Atmel 8-bit AVR microcontroller, 3G cellular modem and various sensors powered with an off-grid solar photovoltaic system to capture real-time fall armyworm moth images, environmental conditions and provide real-time indications of the pest occurrences. The environmental conditions include Geographical Positioning System coordinates, temperature, humidity, wind speed and direction. The captured images together with environmental conditions are uploaded to the cloud server where the image is classified instantly using Google's pre-trained InceptionV3 Machine Learning model. Intended users view captured data including prediction accuracy via a web application. Once this smart technology is adopted, the labour-intensive task of monitoring will reduce while stakeholders shall be provided with a near real-time insight into the FAW situation in the field therefore enabling pro-activeness in their management of such a devastating pest.
... Load and the running time vary from appliance to appliance. Therefore, be careful in measuring and considering the load of appliances or any other devices along with their time of use as the size of stand-alone PV system totally dependent on this step [14]. The energy consumption demand of individual load in Wh (watt-hours) is calculated by multiplying the appliance's load power with its time of use as: ...
... While, the value of voltage rating is the same as the nominal voltage of batteries or a battery. Thus, the ampere size or current rating of solar charge controller is calculated mathematically as [14,15]: ...
... Thus, the battery size or capacity should be increased to 1.5-3 times more to make it oversize rather than undersize [21]. The simplest relationship used to determine the size of batteries or battery bank for a certain load demand is as follow [14]: ...
The stand-alone solar photovoltaic (PV) systems
are a convenient way to provide the electricity for people far
from the electric grid or for people who want the electric power
without any dependence on utility grid, to run their usual
activities either at homes or at businesses. The size of these
systems vary according to the available solar radiations and
different load conditions. Therefore, this paper takes an
organized approach regarding the designing of these systems.
For this purpose, the detailed guidelines and technical
considerations needed in the design process of a solar PV system
is presented for stand-alone application. The guidelines for the
selection of appropriate site/location along with the method for
the assessment of solar energy resource at the chosen site is
provided in this paper. The technical considerations for assessing
the load energy demand on daily basis and sizing of the different
components of solar system including PV panels, charge
controller, storage batteries, inverter and other appurtenances
such as cables etc. required for the design configuration and
installation of a solar PV system are given in this work. So, this
paper will be helpful for designing and installing a solar
PV power system suitable for stand-alone operation in sustaining
the small housing and business communities both in rural
and urban areas.
... Apart from the grid extension PV systems, there is an increasing interest in using stand-alone photovoltaic (SAPV) systems (also known as off-grid) for where access to power grid is costly or difficult (Ali and Salih, 2013;Rezk and El-Sayed, 2013;Kaldellis et al., 2009). These systems mainly include a renewable energy source (solar or wind power), often in combination with batteries for storage and/or diesel generator (Zoulias and Lymberopoulos, 2007;AlShemmary et al., 2013;Li and Yu, 2016;Chowdhury et al., 2015). Considering the mentioned potentials, Kenya is one of the leading SAPV market in the world and the biggest in Africa (Lay et al., 2013). ...
... The literature review shows that a number of studies have investigated energy policies and planning (Parshall et al., 2009;Williams et al., 2015;Habtetsion and Tsighe, 2007;Cherni and Preston, 2007) and energy demand (Zeyringer et al., 2015;Nzia, 2013;Fabini et al., 2014;Kaijuka, 2007) in Kenya. Moreover, numerous studies (Sigarchian et al., 2015;Wasike, 2015;Zoulias and Lymberopoulos, 2007;Ali and Salih, 2013;AlShemmary et al., 2013;Zeyringer et al., 2015;Celik, 2007) have focused on designing a SAPV system which are mainly based on economic analysis (Sigarchian et al., 2015;Wasike, 2015;Zoulias and Lymberopoulos, 2007;AlShemmary et al., 2013). Taking into account both sides of demand and supply, Zeyringer et al. (2015) have suggested detailed assessment of both energies that is often neglected in published studies. ...
... The literature review shows that a number of studies have investigated energy policies and planning (Parshall et al., 2009;Williams et al., 2015;Habtetsion and Tsighe, 2007;Cherni and Preston, 2007) and energy demand (Zeyringer et al., 2015;Nzia, 2013;Fabini et al., 2014;Kaijuka, 2007) in Kenya. Moreover, numerous studies (Sigarchian et al., 2015;Wasike, 2015;Zoulias and Lymberopoulos, 2007;Ali and Salih, 2013;AlShemmary et al., 2013;Zeyringer et al., 2015;Celik, 2007) have focused on designing a SAPV system which are mainly based on economic analysis (Sigarchian et al., 2015;Wasike, 2015;Zoulias and Lymberopoulos, 2007;AlShemmary et al., 2013). Taking into account both sides of demand and supply, Zeyringer et al. (2015) have suggested detailed assessment of both energies that is often neglected in published studies. ...
This work provides a comprehensive approach for electrification of rural areas of Kenya through taking into account both energy demand and supply sides. Toward this, a pre-fabricated composite building is assessed by defining two different levels of energy needs and calculating annual cooling and heating energy demands to keep the occupants within the comfort temperature range. Consequently, four passive cooling techniques (shading, natural ventilation, cool painting and increased thickness of interior gypsum plaster) are applied to decrease the cooling energy demand. Afterwards, A Stand-alone photovoltaic (SAPV) system is designed through sizing of the main components as well as determining the optimum tilt angle and azimuth for the PV array. Finally, four PV technologies (monocrystalline silicon (mono-Si), polycrystalline silicon (poly-Si), cadmium telluride (CdTe) and copper indium selenide (CIS)) were assessed for the designed SAPV system and compared in terms of environmental impact and cost and CIS demonstrated the best performance in all criteria. The results highlight a reduction of about 84% in cooling energy demand through combining all passive cooling techniques originating a house displaying passive behavior. Moreover, the SAPV system proves to be a feasible solution with significant lower cost and GHG emissions in comparison with alternative solutions. The results also outline the importance of the loss of load probability (LLP) in designing SAPV systems indicating a sudden increase in required power of array for LLPs less than 2%.
... Apart from the grid extension PV systems, there is an increasing interest in using stand-alone photovoltaic (SAPV) systems (also known as off-grid) for where access to power grid is costly or difficult ( Ali and Salih, 2013;Rezk and El-Sayed, 2013;Kaldellis et al., 2009). These systems mainly include a renewable energy source (solar or wind power), often in combination with batteries for storage and/or diesel generator ( Zoulias and Lymberopoulos, 2007;AlShemmary et al., 2013;Li and Yu, 2016;Chowdhury et al., 2015). Considering the mentioned potentials, Kenya is one of the leading SAPV market in the world and the biggest in Africa ( Lay et al., 2013). ...
... Consequently, by knowing the total required capacity, number of batteries in series and parallel are respectively calculated using Eqs. (5.9) and (5.10) ( Ali and Salih, 2013;AlShemmary et al., 2013) where Nbs is number of batteries in series, Nbp is number of batteries in parallel and Cb refers to the capacity of one battery. ...
Housing is scarce in the world but even more so in Africa. The construction of current housing solutions in Africa is costly and requires extensive amount of time, labor and materials. Moreover, considering the climate, overheating is a big challenge to be tackled in buildings. This thesis aims to develop a sustainable pre-fabricated sheltering and housing solution for developing countries in Africa. Toward this aim, after an initial material screening, defining criteria for material selection and performing relevant tests and analyses, a multi-criteria decision analysis is performed to identify the optimum solution. Subsequently, a building design of the proposed materials (sandwich-structure composite) is compared with a typical masonry building in terms of environmental impacts. After thermal analysis of this building, the impact of different passive cooling techniques is investigated in terms of indoor air temperature and thermal comfort of the occupants. By identifying the most effective solution of each technique, their combination is assessed to attain an optimized design. Next, the implementation of the proposed building is evaluated in rural areas of Nairobi by determining two levels of energy demand and required cooling and heating energy. The feasibility of energy self-sufficiency is then investigated by designing a stand-alone photovoltaic system. Moreover, the impact of supply of load probability on required power of photovoltaic (PV) array is studied by evaluating different PV technologies. The designed system is then compared with an alternative grid extension to evaluate the environmental benefits of this solution. Finally, the life cycle cost of the proposed building is evaluated and compared with a comparable masonry building throughout their life cycle. Different sensitivity analyses are also performed to assess the influence of parameters such as construction cost, climate and discount and inflation rates. The results demonstrate that the proposed building is a sustainable, passive and energy self-sufficient sheltering and housing solution and that these new technologies can be used to significantly improve the lives of a large number of people and communities.
Simulation of a solar photovoltaic-battery energy system for domestic applications was simulated using HOMER software. Electric load and components’ specifications are the same as those set for a previous study on conventional diesel generator-battery energy system at Pulau Tuba, Langkawi, Malaysia. Based on the simulation results, the renewable energy system can provide adequate electric energy to satisfy existing demands, set at 84 kWh/day average, with 14 kW peak, with some surplus for future demand increase. By comparison, both conventional and renewable energy systems have comparable net present cost, at $179363 and $166576, respectively; and levelized cost of energy, at $0.511/kWh and $0.480/kWh, respectively; despite relatively higher capital cost of the renewable energy system. Renewable energy system is shown to be more beneficial to the environment since it can eliminate air pollutant emissions. Future price reduction and performance improvement of renewable system would make it more competitive.
