Average Solar Fraction Research Articles

Thermal performance study of a vacuum integrated solar storage collector (ISSC) with compound parabolic concentrator (CPC)

This paper deals with the energy performance of a new integrated solar storage collector (ISSC) with compound parabolic concentrator (CPC) conceived in the Thermal Process Laboratory in CRTEn Borj Cedria (North of Tunisia). The novelty in this system is the use of transparent vacuum insulation in the annulus between double half-Cylindrical Plexiglass, and the use of automated nocturnal insulation system, which suppresses heat loss during night. Also, the system is equipped with a mobile support permitting to have many collector orientations toward south, east-south, and west-south in order to maximize the incident solar flux. The experimental study of the ISSC system showed that the thermal loss coefficient of ISSC system is equal to 6.16 W/K for ISSC without nocturnal insulation and without vacuum, 4.69W/K for ISSC without nocturnal insulation and with vacuum, and 4.00 W/K for ISSC with nocturnal insulation and with vacuum. The thermal efficiency of the solar collector is equal to 42.92% for ISSC system fixed without vacuum, 45.95% for ISSC system fixed with vacuum, and 50.56% for ISSC system mobile with vacuum. In order to determine the long-term performance of the vacuum ISSC with CPC, the TRNSYS simulations were carried out by using the component modules modeling the ISSC with CPC concentrator (type 74 and type 60f). Comparison between experimental and predicted results for the temperature difference inside the storage tank during 3 days of January showed reasonable agreement. The numerical results for the ISSC system showed that the annual total energy collected (solar) and auxiliary energy were about 4670 and 1561 MJ, respectively. The annual total auxiliary energy represents about 33.4% of the annual total energy collected (solar). During the summer months (June, July, and August), no auxiliary is needed and the solar fraction (SF) is equal to 100%, where as the annual average SF is about 75%.

Installation and Operation of a Solar Cooling and Heating System Incorporated with Air-Source Heat Pumps

A solar cooling and heating system incorporated with two air-source heat pumps was installed in Ningbo City, China and has been operating since 2018. It is composed of 40 evacuated tube modules with a total aperture area of 120 m2, a single-stage and LiBr–water-based absorption chiller with a cooling capacity of 35 kW, a cooling tower, a hot water storage tank, a buffer tank, and two air-source heat pumps, each with a rated cooling capacity of 23.8 kW and heating capacity of 33 kW as the auxiliary system. This paper presents the operational results and performance evaluation of the system during the summer cooling and winter heatingperiod, as well as on a typical summer day in 2018. It was found that the collector field yield and cooling energy yield increased by more than 40% when the solar cooling and heating system is incorporated with heat pumps. The annual average collector efficiency was 44% for cooling and 42% for heating, and the average coefficient of performance (COP) of the absorption chiller ranged between 0.68 and 0.76. The annual average solar fraction reached 56.6% for cooling and 62.5% for heating respectively. The yearly electricity savings accounted for 41.1% of the total electricity consumption for building cooling and heating.

Thermodynamic analysis of the performance of sub-critical organic Rankine cycle with borehole thermal energy storage

In an effort to reduce fossil fuel consumption and greenhouse gas emissions in the Canadian residential sector for space heating, a first-of-its-kind seasonal solar high-temperature borehole thermal energy storage (BTES) with district heating system for a community of 52 houses was built and has been in operation in Okotos, Alberta, Canada since 2007. In the last five years, the system was able to achieve an average solar fraction and coefficient of performance of 96% and 27, respectively. This study aims to improve the thermal efficiency of the system by implementing a simple organic Rankine cycle (ORC) to generate electricity for operating pumps in the system, and utilizing the solar energy stored in the BTES at 60–80°C as the heat source. The study shows that it is thermodynamically feasible.

Research on the application of phase-change heat storage in centralized solar hot water system

Abstract Solar hot water has attracted growing level of attention due to rapid growth of energy consumption in buildings. Centralized solar hot water system has been widely used in residential buildings in China because it is suitable for multi-story and high-rise buildings. The application of phase change thermal storage in distributed solar hot water system has been widely studied. By contrast, few researches have focused on centralized solar hot water system. This paper aims to investigate the centralized solar hot water system with phase change material (PCM) as thermal energy storage. Through experiments, stainless steel ball was selected as the unit to package paraffin wax, and expanded graphite was added to enhance the heat transfer performance. According to the working temperature of solar collector, two materials with melting temperature of 55 °C and 60 °C were selected to test the properties of heat storage, heat releasing and thermal insulation of the water tank with PCM at different levels of solar irradiation. In addition, solar fraction of the system was calculated based on the maximum daily demand of users. The results showed that the PCM can complete the heat storage within 2–4.5 h at 10.8 MJ/m2, 15.1 MJ/m2 and 19.4 MJ/m2 solar irradiation. The average heat releasing rate was 78% for the 55 °C PCM and 83% for the 60 °C PCM. The average solar fraction of the system with 55 °C PCM was 75% and 80% for the system with 60 °C PCM. Similarly, control mode 1 is more appropriate to the buildings with low occupancy rate or low hot water demand. By contrast, control mode 2 is more appropriate to the buildings with high occupancy rate or large fluctuation of hot water demand. Finally, the results showed that the centralized solar hot water system with PCM performed better than that without PCM. The solar fraction was improved significantly. Meanwhile, it is more effective to use 60 °C PCM in centralized solar hot water system than 55 °C PCM.

Energy Demand Based Procedure for Tilt Angle Optimization of Solar Collectors in Developing Countries

For efficient performance of photovoltaic (PV) panels and flat-plate solar collectors, one of the most important factors that should be considered is tilt angle. The common approach used by researchers has been to calculate the tilt angle (Ss) which maximizes the amount of solar radiation received by the collector. Economically, solar systems must provide a maximum energy to the customer not to collect maximum solar radiation. In some situations, there is a mismatch between them. However, solar harvesters need to be tilted at the correct angle to maximize the performance of the system. In this paper, the average monthly solar fraction of the system (the fraction of energy that is supplied by solar energy) is used as an indicator to find out the optimum tilt angle (Sf) for a solar system. This manner is profitable for most developing countries where there is no law governing the exchange of energy between the main provider of electrical energy in the country (in our case the general electrical company) and investors in the solar energy (for example, house owner). Regardless, that the solar radiation in the case optimum tilt angle based upon the maximum solar radiation collection (Ss) is 4% greater than that of the offered tilt angle (Sf), but we get an improvement in the solar fraction coefficient reached to 0.31%, which is equivalent to a yearly sum of 540 MWh. The solar radiation is calculated using the clear sky ASHRAE model and then multiplied by a magnification factor to meet most of the energy demand. This factor is physically presenting the solar conversion efficiency multiplied by the area of the solar collectors. Having the total monthly energy demand, the monthly solar fraction coefficient can be calculated by dividing the total monthly energy delivered by the solar system by the total monthly energy demand.

An Empirical Study on the Thermal Performance and Dynamic Behavior of Wall Integrated Thermosiphon Solar Water Heater

In this study, the evaluation of the dynamic behavior and thermal performance of the “Façade integrated Natural circulation Solar Water Heating System” installed in the residential house was carried out. Experimental tests were performed during the all year around in the rural houses of 166 m2 in size. Facade integrated solar collector of 5 m2 were installed on the south-facing. Electrical heater of 1 kW capacity as an auxiliary heater was installed at the upper part of the heat storage tank. The analyzing results are as follows. (1) Monthly average solar fraction was 51 to 87% and yearly average value is 64%. (2) Hot water supply temperature in December which has the lowest solar altitude is 37 to 76℃. The highest working fluid temperature of solar collector in this period was below 84℃. The temperature difference of working fluid between the collector inlet and outlet has been shown to be around 9 to 26℃. (3) Overheating which is one of the biggest problems during summer did not appear at all, but rather had hot water supply temperature is rather low as 30~47℃ in summer than winter, which is supplied by a small solar load. The solar collecting temperature has been shown to maintain below 55℃. (5) The thermal performance of Facade integrated solar collector can be increase due to the reduction of heat loss to the back of the collector wall integration of the collector is reduced. As a conclusion, Facade integrated natural circulation type Solar Water Heating System is a well-functioning without any pumps or controllers, and it was found that the disadvantages of conventional solar water heaters, hot water or hot water system can be greatly improved.

Energy and parametric analysis of solar absorption cooling systems in various Moroccan climates

The aim of this work is to investigate the energetic performance of a solar cooling system using absorption technology under Moroccan climate. The solar fraction and the coefficient of performance of the solar cooling system were evaluated for various climatic conditions. It is found that the system operating in Errachidia shows the best average annual solar fraction (of 30%) and COP (of 0.33) owing to the high solar capabilities of this region. Solar fraction values in other regions varied between 19% and 23%. Moreover, the coefficient of performance values shows in the same regions a significant variation from 0.12 to 0.33 all over the year. A detailed parametric study was as well carried out to evidence the effect of the operating and design parameters on the solar air conditioner performance.

Potential of solar industrial process heating in dairy industry in India and consequent carbon mitigation

An attempt to estimate the potential of solar industrial process heating (SIPH) and corresponding mitigation of greenhouse gas emissions in dairy industry in India is presented. An assessment of availability of solar radiation as well as of the ambient conditions at various locations with milk processing plants has been made. The effect of the choice of design value of direct normal irradiance on the annual performance of solar process heating systems has been studied using model developed for hourly simulation of the performance of solar process heating system. Further, state wise estimates for useful thermal energy delivery and corresponding solar fraction have also been obtained.The total process heating potential in term of useful energy requirement in dairy sector in India has been estimated at 6.40 PJ/annum which reduces to 4.50 PJ per annum if the process heating requirement is restricted to only pasteurization stage of milk processing. The corresponding solar collector area requirement for process heating in dairy industry in India is estimated in the range of 1.54–1.83 million m2 with the average solar fraction estimated in the range 0.18–0.32. The use of solar energy for meeting milk processing related thermal energy demand is expected to mitigate (32–144 thousand tonnes) of CO2 emissions annually.

Evaluation of Solar Fraction on a Solar Driven Dual Parallel Connected Ejector Cooling System

This present study reports results of performance evaluation of a solar-driven dual parallel-connected ejector (DPE) cooling system using the concept of solar fraction (SF). The experiments were conducted in July and August, 2015 from 09:00 to 16:00 hours at School of Renewable Energy Technology (SERT), Naresuan University, Thailand, with a solar collector area of 2.4 m2, auxiliary heater of 3 kW, operating at boiler pressure of 2 bar and using water as working fluid. Temperature was measured for inlet and outlet of solar collector. The results showed that the solar collector supplied about 24% of energy required to operate the system. The solar collector performance was 11% and the monthly average SF was 23.9% for July and 23.5% for August.

Modeling, Simulation and Optimization of a Solar Absorption Air Conditioning System for an Office Block in Zaria, Nigeria

In this study, a solar absorption air conditioning system has been modeled simulated and optimized for an office block covering a total floor area of 90[Formula: see text]m2using the TRNSYS 16 software. Meteorological data over a period of a typical year for Zaria in Nigeria where the office block is located was used in the simulation and optimization. The hourly cooling energy demand of the office block for the whole year was simulated using the TRNSYS sub program TRNbuild. The peak cooling energy demand was used to size the components of the solar absorption air conditioning system. Based on the initial sizes, a TRNSYS model of the air conditioning system was developed. The simulation and optimization process was done by employing a monthly average data approach in which the TRNSYS software was combined with Microsoft excel. The simulation was done on an hourly time step, optimization was done by studying effect of varying system component sizes on performance indices: coefficient of performance (COP), solar coefficient of performance (SCOP) and solar fraction (SF). Results indicate that the system is capable of attaining an average annual SF of 0.79 in the given location.

Performance Assessment of Solar Assisted Absorption Heat Pump System with Parabolic Trough Collectors

Abstract A solar assisted absorption heat pump (AHP) system was installed in Tianjin University for space heating in winter and heat water supply. The primary heat source for the AHP is supplied from parabolic trough collectors. In this paper, experimental and simulation are presented to give an overview assessment of the whole system. The performance of the solar collectors in steady and transient state was investigated, the thermal efficiency curve that characterizing the optical and heat loss of the collectors was carried out with a series of tests. For the whole system, the absorption heat pump performance during operating test was measured and presented. The simulation were performed by TRNSYS using the measured meteorological data and the estimated building load with the specific building type and structure, the daily and monthly operation showed that the solar radiation had significant impact on the ratio of useful energy provided by solar collectors, a high instantaneous solar fraction during the sunshine time while a very low average daily solar fraction was seen from the simulation results, this indicated that a thermal storage is necessary to improve the system performance and lower the auxiliary energy usage.

Energetic performances of an optimized passive Solar Heating Prototype used for Tunisian buildings air-heating application

This paper deals with the energetic performances of a Solar Heating Prototype (SHP) conceived in our laboratory to prevail the Tunisian households’ air-heating needs. The conceived SHP mainly consists of a flat-plate solar collector, solar hot water tank and an active layer integrated inside a single room. Firstly, a complete model is formulated taking into account various modes of heat transfer in the SHP by means of the TRNSYS simulation program. To validate the TRNSYS model, experimental tests under local weather conditions were performed for 2days spread over 2months (March and April 2013). Predicted results were compared to the measurements in order to determine the accuracy of the simulation program. A parametric study was then achieved by means of the TRNSYS program in order to optimize SHP design parameters (Collector area, collector mass flow rate, floor mass flow rate, storage tank volume and thickness of the active layer). The optimization of all design parameters shows that to achieve a maximum performances from the SHP it is essential to use a solar collector with an area equal to 6m2 area, a collector mass flow rate equal to 100kgh−1 and a hot water storage tank with a capacity equal to 450l. Concerning the floor heating, the optimal values of mass flow rate and the active layer thickness are 200kgh−1 and 0.06m, respectively. The long-term SHP performances were afterward evaluated by means of the Typical Meteorological Year (TMY) data relative to Tunis, Tunisia. Results showed that for an annual total solar insolation of about 6493.37MJm−2 the average solar fraction obtained is about 84%. The results show also that the request of auxiliary energy is limited to the cold months of the year chiefly from December to Mars. The results show also that the SHP reduce the relative humidity inside the monozone room of about 40%.

Effects of different collector’s area on the coupling of a thermosiphon collector and a single zone

The novelty of this paper is the coupling between a thermosiphon collector and a single zone with the following details; a thermosiphon system (TYPE 45) which uses the solar energy as an unlimited renewable energy to produce the heat by using an internal coupling of a flat plate collector and a storage tank in a closed loop realized in TRNSYS. Consequently, the user simply utilizes TYPE 45 as thermosiphon ready to be run, and a single zone (TYPE 19) is a complex type which is designed for residential buildings that can be specified by the user in order to obtain an acceptable heating within a house. The user specified the characteristics of the internal space, external weather conditions, walls, windows, and doors. To facilitate this description, the parameters and inputs for this component are organized in separate table according to a logical structure. According to us, the choice of this model of thermosiphon coupled with a single zone can have multiple interesting engineering applications, in particular ameliorating the mode of the heating in residential buildings. Two flat plate collectors of aperture area of 6 and 8m2 are modeled. The solar fraction of the entire system is used as the optimization parameter. The temperature of the water in the storage tank, the collector’s temperature, the temperature inside and outside the house, the solar fraction for different collector areas and the total energy were also measured in 11h operation in January and 2880h operation in winter. The average solar fraction obtained was 85% and the system could cover all the hot water needs of a house of six people. The maximum auxiliary energy was needed during 11h operation in January and 4months in winter. The results show that by utilizing solar energy, the designed system could provide 40–70% of the hot water demands in winter.

Long-term performances prediction of an evacuated tube solar water heating system used for single-family households under typical Nord-African climate (Tunisia)

This paper presents a year round energy performance monitoring results of a new type of domestic solar water heating system (DSWH) based on evacuated tube collector (ETC) recently commercialized in Tunisia. This investigation is performed according to two-folded approaches. Firstly, a complete model is formulated taking into account various modes of heat transfer in the DSWH by using TRNSYS simulation program. To validate the TRNSYS model, experimental tests under local weather conditions were performed for 6days spread over 2months (November and July 2010). Predicted results were compared to the measurements in order to determine the accuracy of the simulation program. The long-term system performance was then evaluated by means of the Typical Meteorological Year (TMY) data relative to Borj Cedria, Tunisia. Results showed that for an annual total solar insolation of 5489.3MJ/m2, a total of 4653.13MJ/m2 were collected by the 3.4m2 ETC. For 1047.8MJ/m2 of auxiliary energy supplied to the ETC DSWH system the average solar fraction was 84.4%. An energy performances comparison on yearly basis between the most commercialized flat-plate collector (FPC) DSWH system in Tunisia and ETC DSWH system is also presented in this paper. Results show that the annual average solar fraction of the FPC DSWH systems is lesser (68%) than that of ETC DSWH systems (84%) respectively. It is also found that ETC generated about 9% more energy than the FPC. An economic appraisal was also performed to select the most cost saving between the two DSWH systems.

Investigation of a solar cooling installation in Tunisia

In this paper, we present a solar cooling installation located at the Center of Researches and Energy Technologies (CRTEn), in Bordj-Cédria, Tunisia. It is composed mainly of parabolic trough solar collectors, a 16kW LiBr double effect absorption chiller associated with a cooling tower, a backup heater, two tanks for storage and drain-back storage and a set of fan-coils installed in the building to be conditioned. The system was run in the summers 2008 and 2009 using a water solution as heat transfer medium (HTF) without storage. In summer 2010, thermal oil was used as a HTF instead of water and two tanks were added, one for temperatures stabilities and the other one as a backup tank for night storage. Two running strategies of the installation were adopted; starting with or without backup heater. The site specifications, the building loads, the chillier temperatures and heat flows, the parabolic trough solar collector efficiencies, the installation powers and performances were analyzed. It was found that the coefficient of performance COP was ranged between 0.8 and 0.91 during the installation running while the solar coefficient of performance SCOP was between 0.1 and 0.43. The maximum output of the absorption chiller was around 12kW. The drain backup night storage has improved the average solar fraction SF of the system which increased from 0.54 to 0.77. The avoided CO2 emission during a cooling season was estimated to be about 3000kg corresponding to an equivalent energy saving of 1154l of gasoil.

Performance simulation of a solar-assisted micro-tri-generation system: hotel case study

In this work, a micro-tri-generation system integrated with a solar system is studied. A basic micro- cogeneration technology (micro-CHP (combined heat and power) system) integrating solar collectors, storage tank, micro-turbine and a thermodynamic cycle based on the organic Rankine cycle (ORC) is combined with an absorption chiller. The heat rejected at the condenser of the micro-CHP system is used for water heating (WH), and the absorption chiller is used for space cooling. Hot water from the solar storage tank is the heat source for the cooling system (absorption chiller) and the micro-CHP system. A heat exchanger is used to transfer heat from the hot water circuit to the power cycle (which uses an organic refrigerant). The micro-CHP system under analysis uses a micro-turbine and an electric generator with a power output of 5 kW. The turbine inlet temperature is 808C and the working fluid is cyclohexane. The absorption chiller, which is a single-effect water-fired chiller, operates with a lithium bromide and water mixture, and water inlet temperature is between 80 and 1008C. The performance for different solar collector areas and tank capacities was evaluated through a numerical model. A hotel building was used as a case study and the analysis was extended throughout the cooling season, for climatic conditions of different European cities: Athens (Greece), Lisbon (Portugal), Madrid (Spain), Paris (France) and London (UK). The monthly average solar fraction was evaluated for different cases: the micro-CHP system, the cooling system and the micro-tri-generation system with the useful condenser energy used for WH. The solar fraction of the micro-CHP system was low, compared with that of the cooling system, because the efficiency of the micro-CHP system is lower than 7%. However, when the tri-generation system is considered, the monthly average solar fraction is much higher, due to the utilization of the condenser heat. The solar system, cooling system and its components were modelled with the TRNSYS simulation program. The micro-CHP system was modelled with EES software.

Experimental and numerical study of a directly PV-assisted domestic hot water system

► PV-assisted Solar Domestic Hot Water system. ► The different control mode of the SDHW systems. ► The start-up characteristics of the solar pump optimized through various electronic devices. ► The evaluation of the yearly energy performance of the PV-SDHW system. The solar domestic hot water (SDHW) system is the most highly developed system for use of solar energy. The developments for the thermal regulation of buildings should reinforce this trend given the significant reduction of heating needs. Currently, the design of these SDHW installations is well controlled and the system performance is reasonably good. The annual average solar fraction is consistent with expected level (between 60% and 70%) according to a report of CSTB by evaluating 120 SDHW installations ( Buscarlet and Caccavelli, 2006 ). However, the control mode of conventional SDHWs induces additional costs related to the consumption of auxiliaries and other risks of dysfunction of the circulation pump due to the temperature probes and controller setup which induces low annual productivity of solar collector (200 instead of 400 kW h/m 2 expected). From this point of view, the photovoltaic pumped system seems suitable since it eliminates the controller and temperature sensors. This paper focuses on an experimental and numerical study of the behavior of a PV-SDHW system, focusing on the start-up phase optimized through various electronic devices. A detailed model of a circulation pump was developed by considering a direct current (DC) circulation pump coupled with various electronic devices (linear current booster and maximum power point tracker). The developed models were then validated experimentally, to reveal the influence of the threshold solar radiation on the circulation pump start-up and the pump flow rate as a function of the solar radiation, and its effects on the annual energy performance of PV-SDHW systems.

Optimal study of a solar air heating system with pebble bed energy storage

The application of solar air collectors for space heating has attracted extensive attention due to its unique advantages. In this study, a solar air heating system was modeled through TRNSYS for a 3319 m 2 building area. This air heating system, which has the potential to be applied for space heating in the heating season (from November to March) and hot water supply all year around in North China, uses pebble bed and water storage tank as heat storage. Five different working modes were designed based on different working conditions: (1) heat storage mode, (2) heating by solar collector, (3) heating by storage bed, (4) heating at night and (5) heating by an auxiliary source. These modes can be operated through the on/off control of fan and auxiliary heater, and through the operation of air dampers manually. The design, optimization and modification of this system are described in this paper. The solar fraction of the system was used as the optimization parameter. Design parameters of the system were optimized by using the TRNSYS program, which include the solar collector area, installation angle of solar collector, mass flow rate through the system, volume of pebble bed, heat transfer coefficient of the insulation layer of the pebble bed and water storage tank, height and volume of the water storage tank. The TRNSYS model has been verified by data from the literature. Results showed that the designed solar system can meet 32.8% of the thermal energy demand in the heating season and 84.6% of the energy consumption in non-heating season, with a yearly average solar fraction of 53.04%.

Hybrid photovoltaic/thermal (PV/T) solar systems simulation with Simulink/Matlab

The purpose of this work consists in thermodynamic modeling of hybrid photovoltaic–thermal (PV/T) solar systems, pursuing a modular strategy approach provided by Simulink/Matlab. PV/T solar systems are a recently emerging solar technology that allows for the simultaneous conversion of solar energy into both electricity and heat. This type of technology present some interesting advantages over the conventional “side-by-side” thermal and PV solar systems, such as higher combined electrical/thermal energy outputs per unit area, and a more uniform and aesthetical pleasant roof area. Despite the fact that early research on PV/T systems can be traced back to the seventies, only recently it has gained a renewed impetus. In this work, parametric studies and annual transient simulations of PV/T systems are undertaken in Simulink/Matlab. The obtained results show an average annual solar fraction of 67%, and a global overall efficiency of 24% (i.e. 15% thermal and 9% electrical), for a typical four-person single-familiar residency in Lisbon, with p-Si cells, and a collector area of 6 m 2. A sensitivity analysis performed on the PV/T collector suggests that the most important variable that should be addressed to improve thermal performance is the photovoltaic (PV) module emittance. Based on those results, some additional improvements are proposed, such as the use of vacuum, or a noble gas at low-pressure, to allow for the removal of PV cells encapsulation without air oxidation and degradation, and thus reducing the PV module emittance. Preliminary results show that this option allows for an 8% increase on optical thermal efficiency, and a substantial reduction of thermal losses, suggesting the possibility of working at higher fluid temperatures. The higher working temperatures negative effect in electrical efficiency was negligible, due to compensation by improved optical properties. The simulation results are compared with experimental data obtained from other authors and perform reasonably well. The Simulink modeling platform has been mainly used worldwide on simulation of control systems, digital signal processing and electric circuits, but there are very few examples of application to solar energy systems modeling. This work uses the modular environment of Simulink/Matlab to model individual PV/T system components, and to assemble the entire installation layout. The results show that the modular approach strategy provided by Matlab/Simulink environment is applicable to solar systems modeling, providing good code scalability, faster developing time, and simpler integration with external computational tools, when compared with traditional imperative-oriented programming languages.

Optimal Design for a Thermosyphon Solar Water Heater Convenient for Malaysia

A thermosyphon solar water heating system with in‐tank auxiliary electric heater has been simulated according Malaysian hot water consumption profile using TRNSYS simulation program. The optimum value of a parameter is defined as the value which maximized the annual solar fraction of the system. This paper has a good deal of information concerning sizing of common components of thermosyphon solar water heater operated under certain condition (load volume, distribution profile and temperature). The results indicate that collector should be tilted at Ø + (→ 7° 37°) for all collector areas. Vertical storage tank has better performance in tropical climate (The average annual solar fraction for vertical was 88% and for horizontal was 82.9%).