scholarly journals Optimum Tilt Angle at Tropical Region

2015 ◽  
Vol 4 (1) ◽  
pp. 48-54 ◽  
Author(s):  
S Soulayman ◽  
W Sabbagh

: One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector Equator facing position is the best, is valid for tropical region? Thus, it is required to determine the optimum tilt as for Equator facing and for Pole oriented collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector tilt angle for a definite value of surface azimuth angle? A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle) for the solar collector at any latitude. This model was applied for determining optimum tilt angle and orientation in the tropical zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle) maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of 11% to 18% more than the case of a solar collector fixed on a horizontal surface.

2012 ◽  
Vol 16 (suppl. 2) ◽  
pp. 471-482 ◽  
Author(s):  
Velimir Stefanovic ◽  
Sasa Pavlovic ◽  
Marko Ilic ◽  
Nenad Apostolovic ◽  
Dragan Kustrimovic

Solar energy may be practically utilized directly through transformation into heat, electrical or chemical energy. A physical and mathematical model is presented, as well as a numerical procedure for predicting thermal performances of the P2CC solar concentrator. The demonstrated prototype has the reception angle of 110? at concentration ratio CR = 1.38, with the significant reception of diffuse radiation. The solar collector P2CC is designed for the area of middle temperature conversion of solar radiation into heat. The working fluid is water with laminar flow through a copper pipe surrounded by an evacuated glass layer. Based on the physical model, a mathematical model is introduced, which consists of energy balance equations for four collector components. In this paper, water temperatures in flow directions are numerically predicted, as well as temperatures of relevant P2CC collector components for various values of input temperatures and mass flow rates of the working fluid, and also for various values of direct sunlight radiation and for different collector lengths. The device which is used to transform solar energy to heat is referred to as solar collector. This paper gives numerical estimated changes of temperature in the direction of fluid flow for different flow rates, different solar radiation intensity and different inlet fluid temperatures. The increase in fluid flow reduces output temperature, while the increase in solar radiation intensity and inlet water temperature increases output temperature of water. Furthermore, the dependence on fluid output temperature is determined, along with the current efficiency by the number of nodes in the numerical calculation.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 623 ◽  
Author(s):  
Ramez Abdallah ◽  
Adel Juaidi ◽  
Salameh Abdel-Fattah ◽  
Francisco Manzano-Agugliaro

The optimum tilt angle of solar panels or collectors is crucial when determining parameters that affect the performance of those panels. A mathematical model is used for determining the optimum tilt angle and for calculating the solar radiation on a south-facing surface on a daily, monthly, seasonal, semi-annual, and annual basis. Photovoltaic Geographical Information System (PVGIS) and Photovoltaic Software (PVWatts) is developed by the NREL (US National Renewable Energy Laboratory) are also used to calculate the optimum monthly, seasonal, semi-annual, and annual tilt angles and to compare these results with the results obtained from the mathematical model. The results are very similar. PVGIS and PVWatts are used to estimate the solar radiation on south-facing surfaces with different tilt angles. A case study of a mono-crystalline module with 5 kWP of peak power is used to find out the amount of increased energy (gains) obtained by adjusting the Photovoltaic (PV) tilt angles based on yearly, semi-annual, seasonal, and monthly tilt angles. The results show that monthly adjustments of the solar panels in the main Palestinian cities can generate about 17% more solar energy than the case of solar panels fixed on a horizontal surface. Seasonal and semi-annual adjustments can generate about 15% more energy (i.e., it is worth changing the solar panels 12 times a year (monthly) or at least 2 times a year (semi-annually). The yearly optimum tilt angle for most Palestinian cities is about 29°, which yields an increase of about 10% energy gain compared to a solar panel fixed on a horizontal surface.


Proceedings ◽  
2018 ◽  
Vol 2 (20) ◽  
pp. 1272 ◽  
Author(s):  
Dorota Anna Krawczyk ◽  
Mirosław Żukowski ◽  
Antonio Rodero ◽  
Ruta Bilinskiene

A solar collector market is most European countries is at the stage of continuous development, however its expansion rate differs. It shows that much more factors than only the local solar radiation is important, including a technology progress, costs, local manufactures’ engagement, an economic government support or an environmentally consciousness raising relevant to a mitigating climate change. We conducted the analysis for a public office building, with a few toilets and a social room, used by 54 people. As a primary heat source for HVAC and DHW systems an oil boiler was used, whereas solar collectors were considered as an energy source for hot water preparation. The analysis was conducted for three locations of the building: Bialystok (Poland), Cordoba (Spain) and Kaunas (Lithuania), using a simulation software delivered within the framework of VIPSKILLS project. Theoretical hot water consumption was considered as 3–7 dm3/(day person) in compliance with national recommendations. It was found that beam solar radiation share in a total radiation balance was nearly twice higher in Cordoba than in Bialystok or Kaunas. The highest efficiency (44%) was estimated in Cordoba for solar collectors installed with the tilt angle between 45–50°. In case of Bialystok and Kaunas the efficiency was lower than in Cordoba and nearly equal 40–41% and the recommended tilt angle was in a range 30– 45°.


Author(s):  
Ashutosh Sharma ◽  
Mehmet Ali Kallioğlu ◽  
Anchal Awasthi ◽  
Ranchan Chauhan ◽  
Gusztáv Fekete ◽  
...  

Author(s):  
Muhammad Uzair ◽  
Syed Umair Hassan Kazmi ◽  
Muhammad Uzair Yousuf ◽  
Syed Asad Ali Zaidi

To incorporate solar energy efficiently into a country, it is needed to know the optimal tilt and azimuth angle of the solar collectors' location. Also, to build a solar park, it is necessary to know the most suitable and high-energy generating place inside a country, thus saving time and money. This study analyzed collector geometry for Karachi in particular and Pakistan in general. Karachi has the potential of 339.36 kW-hr/m2/annum energy at an annually optimal fixed tilt of 26°. In case collector geometry had to be changed in Karachi, a range of 40° azimuth angle and 20° tilt angle from its maximum value is available. The power produced in this case would only have a difference of 1%. Optimal yearly and monthly tilt of most of the locations of Pakistan (300+) were calculated. Through them, it was revealed that the Optimal Tilt of Pakistan follows the value of latitude closely. Generally, changing the tilt angle monthly is recommended for areas that produce more energy, while fixed annual tilt could be suitable for low energy-producing regions. Effects of temperature were also incorporated while finding the energy produced by the photovoltaic (PV) panels.


2012 ◽  
Vol 253-255 ◽  
pp. 766-771 ◽  
Author(s):  
Maryam Khademi ◽  
Farzad Jafarkazemi ◽  
S. Ali Saadabadi ◽  
Ehsan Ghazi

In present research we propose a nonlinear solving method to obtain the optimum tilt angle for solar panels. For this purpose, solar radiation on tilted panels are estimated by applying anisotropic model in Maple and the maximum is obtained by solving parametric nonlinear equations with Sequential Quadratic Programming (SQP) algorithm. Comparing its results with prevalent calculation proved this method faster and more efficient. The used model is validated by comparing results with measured data on a 45o-tilted surface in Tehran, Iran. Results showed solar radiation on a tilted surface increases 32% by monthly adjustments, in comparison with a fixed horizontal surface.


Author(s):  
Ferenc GáSPáR ◽  
Mugur BÄ‚LAN ◽  
Lorentz Já„NTSCHI ◽  
Victor ROȘ

In the paper the global solar radiation incident on a fixed spherical solar collector is evaluated and compared to a south oriented with 46 grade tilt angle fixed flat plate solar collector. Mean daily and hourly solar radiation are calculated from existing data for Cluj-Napoca, Romania. The results show that depending on the equivalent absorbing surface area taken into account, spherical collectors can be more efficient in receiving solar radiation than flat plate collectors.


2005 ◽  
Vol 129 (2) ◽  
pp. 253-255 ◽  
Author(s):  
Hongxing Yang ◽  
Lin Lu

The tilt and azimuth angles of a photovoltaic (PV) array affect the amount of incident solar radiation exposed on the array. This paper develops a new mathematical model for calculating the optimum tilt angles and azimuth angles for building-integrated photovoltaic (BIPV) applications in Hong Kong on yearly, seasonal, and monthly bases. The influence of PV cladding orientation on the power output of PV modules is also investigated. The correlations between the optimum tilt angle and local weather conditions or local environmental conditions are investigated. The results give reasonable solutions for the optimum tilt angles for BIPV applications for both grid-connected and stand-alone systems.


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