scholarly journals Effect of Total Solar Radiation and Rainfall on Yield of Different Tea (Camellia sinensis [L.] O. Kuntze) Clones at Two Sites in Kenya

2018 ◽  
Vol 10 (6) ◽  
pp. 40
Author(s):  
Joseph Kimutai Langát
Keyword(s):  
Solar Radiation ◽  
Camellia Sinensis ◽  
Climatic Conditions ◽  
Total Solar Radiation ◽  
Strong Positive Correlation ◽  
Research Reporting ◽  
Split Plot ◽  
3.0 T ◽  
Tea Production ◽  
Weather Changes

Tea cultivation is the leading cash crop in Kenya, making significant contribution to the economy. It is the single largest export commodity, accounting for about 26% of the country’s total export earnings. In 2017, the country got US$ 1.23 billion in foreign exchange earnings. However, tea production is affected by weather changes. Majority of research reporting the effects of weather on tea yields in Africa have mostly been carried out at single sites. This study investigated contribution of total solar radiation and rainfall to tea (Camellia sinensis) yields at two sites in Kenya. A split-plot layout study was conducted at two sites differing in altitude and climatic conditions in Kenya: Kangaita (0o30'S, 37o16'E, 2100 m.a.s.l.) and Kipkebe (0o17'S, 35o3'E, 1740 m.a.s.l.). Timbilil (0o22'S, 35o21'E, 2200 m.a.s.l.) was used as a reference site. Four tea clones of commercial and scientific interest in Kenya (AHP SC 31/37, EPK TN14-3, TRFK 301/5 and TRFK 31/8) were studied. Low radiation intensities at Timbilil in 2007 corresponded with low made tea yields at Kangaita (2.1 t ha-1 y-1) and Kipkebe (2.6 t ha-1 y-1) compared to 2008 (4.4 t ha-1 y-1 and 3.2 t ha-1 y-1) and 2009 (3.1 t ha-1 y-1 and 3.0 t ha-1 y-1) respectively when higher total radiation intensities were recorded. Statistical analysis done using two-way ANOVA (P = 0.05) for split plot design showed a strong positive correlation (r = 0.53) between total solar radiation, rainfall and mean made tea yield. Higher radiation and rainfall intensities yielded higher tea outputs.

scholarly journals Determining the optimum orientation of a greenhouse on the basis of the total solar radiation availability

2011 ◽  
Vol 15 (1) ◽  
pp. 215-221 ◽  
Author(s):  
Snezana Dragicevic
Keyword(s):  
Solar Radiation ◽  
Close Agreement ◽  
Experimental Validation ◽  
Global Solar Radiation ◽  
Climatic Conditions ◽  
Total Solar Radiation ◽  
Radiation Data ◽  
Solar Greenhouse ◽  
South Wall ◽  
East West

This paper presents an approach to determining the optimum orientation of a greenhouse for year round applications for different climatic conditions. The most commonly used uneven-span single shape of greenhouse in east-west and north-south orientation have been selected for comparison. Total solar radiation input to each wall, included surfaces and roofs, is computed for both solar greenhouse orientation and compared for each month of the year at different latitudes at the northern hemisphere. Experimental validation is carried out for the measured global solar radiation data for horizontal surface and south wall at (44?N and 20?E), Belgrade, Serbia. The predicted and measured values are in close agreement. Results shows that east-west orientation of uneven-span solar greenhouse is the best suited during each months for all analyzed latitudes.

scholarly journals Autonomous complex for electro-thermal heating of oil wells fed by a photovoltaic installation

2021 ◽  
Vol 266 ◽  
pp. 04006
Author(s):  
Y.E. Shklyarskiy ◽  
V.V. Starshaya
Keyword(s):  
Solar Radiation ◽  
Energy Savings ◽  
Electricity Consumption ◽  
Reducing Power ◽  
Oil Production ◽  
Electric Heating ◽  
Climatic Conditions ◽  
Total Solar Radiation ◽  
Oil Well ◽  
Solar Panels

Paraffin deposits are a serious problem causing complications in oil production. This article describes the creation of a complex operatingonphotovoltaic installations to combat paraffin deposits. The authors offer an innovative method for accurate calculation of the parameters of photovoltaic installations, taking into account changes in total solar radiation, geographical and climatic conditions, the angle of inclination of solar panels, characteristics of the power source, and oil parameters. Measurements of solar radiation are carried out on the basis of mathematical and simulation modeling in Matlab Simulink. The results of the studies confirm the adequacy of the proposed method of oil well heating. This method of electric heating has a simple design and does not require underground works and well shutdown. Thus, it will improve the efficiency of oil production, prevent the formation of paraffin deposits, and ensure energy savings by reducing power losses and electricity consumption.

scholarly journals Trees as a solar control measure for southern-oriented street frontages. Analysis of a selected street model for a humid continental climate

2021 ◽  
Author(s):  
Katarzyna Zielonko-Jung ◽  
Justyna Janiak
Keyword(s):  
Numerical Simulation ◽  
Solar Radiation ◽  
Control Measure ◽  
Total Solar Radiation ◽  
Single Row ◽  
Ground Floor ◽  
Radical Reduction ◽  
Solar Control ◽  
Sycamore Maple ◽  
Continental Climate

AbstractThe present study is aimed at the analysis of possibilities for shading southern frontage of street oriented along the E-W axis by the single row of trees, parallel to the southern elevations. The effectiveness of solar control shading was tested depending on the geometric relationships between trees and buildings. Numerical simulation analyses were conducted in Rhinoceros® program for the street located in humid continental climate in city Płock, Poland (52°32′50 “N 19°42’00 “E), for the day of the highest degree of total solar radiation in the year i.e. June 7th, during hours: 8.00a.m - 5.00 p.m. The analysis has proved that a row of 20–25 year old Sycamore Maple ‘Rotterdam’ in the street 30 m wide and 18 m high (H/W = 0.6), can provide solar protection for the southern frontage, especially when trees are located no more than 4 m away. Location of greenery within the range of 4 to 5 m from the buildings leads to a radical reduction in the possibility of shading the wall surfaces (at 5 m to 0%). Over 90% of the shading area of the ground floor façade walls was found when trees were within the distance 2 and 3 m away from the building.

Estimation of the total solar radiation from meteorological data

Solar Energy ◽  
1977 ◽  
Vol 19 (3) ◽  
pp. 307-311 ◽  
Author(s):  
J.A. Sabbagh ◽  
A.A.M. Sayigh ◽  
E.M.A. El-Salam
Keyword(s):  
Solar Radiation ◽  
Meteorological Data ◽  
Total Solar Radiation

scholarly journals The Potential of Solar Air Heating in the Turkish Industrial Sector

2018 ◽  
Vol 63 (1) ◽  
pp. 57-66
Author(s):  
Balázs Bokor ◽  
Hacer Akhan ◽  
Dogan Eryener ◽  
László Kajtár
Keyword(s):  
Solar Radiation ◽  
Energy Savings ◽  
Measurement Data ◽  
Industrial Sector ◽  
Climatic Conditions ◽  
Cold Climate ◽  
Conventional Heating ◽  
Industrial Building ◽  
High Solar Radiation ◽  
Mathematical Correlation

Transpired solar collector (TSC) systems are simple solutions for the preheating of ventilation air with solar energy. Their performance is a function of several environmental factors, so the climatic conditions of the location play an important role. In this paper, the effect of different climatic zones on the thermal performance of the TSC is investigated. To exclude other sources of influence, the same reference industrial building is examined in four Turkish locations (Antalya, Istanbul, Ankara and Sivas) representing different climatic conditions. RETScreen simulation is carried out for all four regions to obtain the drop of conventional heating requirement in case absorber azimuth of 0°, 45° and 90°. To illustrate the performance, temperature rise, heating energy savings and annual solar fraction are presented. Generally, it can be stated that a location with cold climate and high solar radiation at the same time benefits most from the use of a TSC system. A mathematical correlation has been found showing the solar fraction's dependence on solar radiation and heating degree days. Finally, simulation results have been compared to a set of measurement data from an industrial building's TSC system near Istanbul.

scholarly journals High resolution grid of potential incoming solar radiation for Serbia

2015 ◽  
Vol 19 (suppl. 2) ◽  
pp. 427-435 ◽  
Author(s):  
Jelena Lukovic ◽  
Branislav Bajat ◽  
Milan Kilibarda ◽  
Dejan Filipovic
Keyword(s):  
Solar Radiation ◽  
Driving Force ◽  
Total Solar Radiation ◽  
Surface Solar Radiation ◽  
Natural Processes ◽  
Web Map ◽  
Complex Interactions ◽  
The Earth ◽  
Digital Elevation ◽  
Elevation Model

Solar radiation is a key driving force for many natural processes. At the Earth?s surface solar radiation is the result of complex interactions between the atmosphere and Earth?s surface. Our study highlights the development and evaluation of a data base of potential solar radiation that is based on a digital elevation model (DEM) with a resolution of 90 m over Serbia. The main aim of this paper is to map solar radiation in Serbia using DEM. This is so far the finest resolution being applied and presented using DEM. The final results of the potential direct, diffuse and total solar radiation as well as duration of insolation databases of Serbia are portrayed as thematic maps that can be communicated and shared easily through the cartographic web map-based service.

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