scholarly journals Performance Analysis of a Floating Photovoltaic System and Estimation of the Evaporation Losses Reduction

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8336
Author(s):  
Arnas Majumder ◽  
Roberto Innamorati ◽  
Andrea Frattolillo ◽  
Amit Kumar ◽  
Gianluca Gatto
Keyword(s):  
Environmental Conditions ◽  
Water Surface ◽  
Photovoltaic System ◽  
Water Evaporation ◽  
True Temperature ◽  
Efficiency Gain ◽  
Water Cooling ◽  
Positive Effects ◽  
Pv Panel ◽  
Water Surface Area

Our research aims to achieve dual-positive effects in the presented study by raising photovoltaic (PV) panels over the water surface. With this, target experiments were primarily conducted to evaluate the efficiency increments of the PV panel while reducing its operating temperature through passive convective cooling obtained by raising it over water. The following objective was to estimate the reduction in water evaporation due to the shading effect induced by the panel placed inside the same basin. The performance of two PV panels was analyzed, one used for tests, the other as a reference. The characteristic curves were determined under the local environmental conditions of Cagliari, Italy. The true temperature reduction and efficiency gain calculations of panel P1 due to water cooling was achieved via the measured temperatures and calculated efficiencies of panel P2 at environmental conditions. The water height inside the basin was constantly monitored and maintained at approximately 7.5 cm below panel P1, which covered about 17% of the total water surface area. The presence of water underneath P1 leads to its efficiency increment on average by 2.7% (absolute) and about 17.22% (relative). At the same time, temperature of panel P1 dropped by 2.7 °C on average. The comparative water evaporation study conducted with and without P1 inside the basin showed a 30% reduction in water evaporation.

RATE OF EVAPORATION FROM A FREE-WATER SURFACE AS INFLUENCED BY EXPOSURE

1961 ◽  
Vol 41 (1) ◽  
pp. 199-203 ◽  
Author(s):  
A. C. Carder
Keyword(s):  
Water Surface ◽  
Meteorological Factors ◽  
Free Water ◽  
Water Evaporation ◽  
High Wind ◽  
Progressive Decrease ◽  
Factors Affecting ◽  
Wind Velocities ◽  
Rate Of Evaporation ◽  
Low Rate

In a 3-year free-water evaporation study, an evaporimeter tank in the open field lost 34.5 per cent more water than a tank sheltered by buildings and trees. Meteorological factors responsible for this difference appear to be high wind velocities and long daily periods of sunshine. Changes in temperature regime had no effect.Difference in evaporation from the two tanks led to examination of data obtained over 35 years from the sheltered tank. It was found that, although there was a progressive decrease in amount of evaporation over the years from this tank, rainfall at the same time had increased and that the effect of this increase on evaporation was roughly equal to that of all other factors affecting evaporation, such as a change in exposure, etc. Thus, the comparatively low rate of evaporation from the sheltered tank was undoubtedly due in part to the proximity of buildings and trees which had been established.

scholarly journals Determination the optimal tilt and azimuth angle of photovoltaic system for maximum energy in Bucharest region, Romania - Case Study

2019 ◽  
Vol 80 ◽  
pp. 01007
Author(s):  
Mihaela Andreea Mitiu ◽  
Marius Viorel Olteanu ◽  
Gyorgy Deak ◽  
Natalia Simona Raischi ◽  
Danut Cociorva
Keyword(s):  
Tilt Angle ◽  
Maximum Energy ◽  
Azimuth Angle ◽  
Photovoltaic System ◽  
Optimal Position ◽  
Photovoltaic Panels ◽  
Pv Panel ◽  
One Year ◽  
Annual Amount

This study was conducted to evaluate the feasibility of installing a photovoltaic system for supplying the electric load of an environmental institute and to determinate the optimal tilt and azimuth angle of an 100 kW photovoltaic power plant located on the roof of institute. Those parameters plays an important role in maximizing the solar radiation collected by a PV panel. Simulations were made with PVsyst V6.39 for south-east orientation (100; 450) and south-west orientation (100; 450), and for the tilt angle the simulations were made at 100, 150, 370, 600 and 900. The simulation has been done to study the influence of the photovoltaic panels orientation on the amount of electricity produced each month of the year as well as on the total annual amount of electricity. Was experimentally determined by repetitive simulations in the range 300-400 for tilt angle and zero azimuth, optimal parameters for the position of photovoltaic panels. Was defined as the optimal position, the pair of values [zero azimuth, tilt angle 370] where the plant generates maximum energy in one year compared to any other set of values that defines the position of the photovoltaic panels.

scholarly journals Impacts of Rapid Changes of Land Cover and Intensive Human Activities on Avarga Toson Lake Area, Mongolia

2020 ◽  
Vol 12 (15) ◽  
pp. 6070
Author(s):  
Urtnasan Mandakh ◽  
Danzanchadav Ganbat ◽  
Bayartungalag Batsaikhan ◽  
Sainbayar Dalantai ◽  
Zolzaya Adiya ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Surface Area ◽  
Human Activities ◽  
Water Surface ◽  
Land Development ◽  
Water Area ◽  
Lake Area ◽  
Surrounding Area ◽  
Water Surface Area

Avarga Toson Lake and its surrounding area are very important for people, wildlife, and animals in Delgerkhaan Soum of Khentii Province in Eastern Mongolia. Some research has been conducted so as to explore the medical nature and characteristics of the lake and its surrounding area. However, the adverse effects of land use have neither been studied nor reported. The fact that the water catchment area is shrinking evidences clearly that findings of various real-time studies must be used effectively in the long-term by the local government and relevant authorities in order to take immediate remedial measures. Our study focused on land cover changes occurring as a result of human activities in the area, using a Landsat imageries and water indices approach to estimate the changes of land use and land cover. The aims of this study were to assess the land use and cover change that occurred between 1989 and 2018 and to define the impacting factors on the changes of water surface area in Avarga Toson Lake area, Mongolia. Findings revealed that the water surface area has decreased by 34.1% in the past 30 years. The lake water area had the weakest, positive correlation with temperature and precipitation. We did not find any indicators suggesting a relationship between lake area and climate variables. In contrast, the area was slightly correlated with socio-economic variables, such as Toson Lake area with the number of visitors (R2 = 0.89) and Burd Lake area the with number of livestocks (R2 = 0.75), respectively. Therefore, the main conclusion of this paper is that socioeconomic factors driven by land use change, policy, and institutional failure together with the existing pressure on the lake may amplify their effect of the water surface area decreasing. Additionally, even if policy adoption is relatively sufficient in the country, the public institutional capacity to implement a successful sustainable land management model regarding land access, land development, land resources protection, land market, and investments in infrastructure remains very limited.

scholarly journals Effect of air parameters, water temperature, and number of pool occupants on moisture gains

2018 ◽  
Vol 70 ◽  
pp. 02006
Author(s):  
Agnieszka Garnysz-Rachtan ◽  
Zbigniew Zapałowicz
Keyword(s):  
Water Temperature ◽  
Water Surface ◽  
Evaporation Rate ◽  
Water Evaporation ◽  
Physical Parameters ◽  
Air Humidity ◽  
Air Velocity ◽  
Relative Air Humidity ◽  
Thermal Calculations ◽  
The Right

Thermal calculations for indoor swimming pools require that amount of water evaporated from the pool's water surface, as well as water evaporated from the floor surrounding the pool and from the bodies of the occupants are to be determined. It means in practice that amount of vapor transferred to the air in the pool hall depends most of all on physical parameters of water and air. One of more important factors that affect water evaporation is also the way the pool is operated. The present article shows only chosen relations applied to determine the values of evaporation rate from occupied pool. The relations also account for the mode of pool's operation. The aim of the paper is to analyse the effect of changes of temperature and of relative air humidity in the hall, of water temperature and of air velocity above the water surface, as well as of the number of occupants on moisture gains in the hall. The above data let choose the right relation to be applied in calculations for the water evaporation rate.

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