scholarly journals Calculation of efficiency of work of converters of energy of solar heat and electric stations

2020 ◽  
Vol 209 ◽  
pp. 03019
Author(s):  
Nikolay Moskalenko ◽  
Maryana Khamidullina ◽  
Azat Akhmetshin
Keyword(s):  
Solar Radiation ◽  
Anthropogenic Impacts ◽  
Short Wave ◽  
Hot Water ◽  
Solar Thermal ◽  
Wave Radiation ◽  
Water Supply Systems ◽  
Radiation Heat Exchange ◽  
The Impact ◽  
Spectral Intensities

The modeling of complex radiation heat exchange in the system “Sun-atmosphere-solar thermal and electric stations” is considered. The structural scheme of solar radiation inflows to the heat-absorbing surface of solar thermal and electrical stations is discussed. Calculations of spectral intensities and the flux of solar radiation, taking into account the selectivity of molecular absorption of radiation by the ingredients of the gas phase of the atmosphere, scattering and absorption of radiation by atmospheric aerosol and clouds, taking into account the statistics of their distribution depending on the location of the station and the time of year. Modeling of anthropogenic impacts on the operation of solar thermal and electrical stations in connection with the capture of anthropogenic emissions of sols by clouds is performed. An assessment of the impact of economic activity on the work of promising solar thermal and electrical stations. The developed methods for calculating the spectral intensities and fluxes of short-wave and long-wave radiation on the underlying surface make it possible to calculate the efficiency of the functioning of solar hot water supply systems for any location and structural solution.

Prévision des températures de l'eau en rivières à l'aide d'un modèle conceptuel : le cas de la rivière Moisie

1994 ◽  
Vol 21 (1) ◽  
pp. 63-75 ◽  
Author(s):  
Guy Morin ◽  
Tonino-Joseph Nzakimuena ◽  
Wanda Sochanski
Keyword(s):  
Solar Radiation ◽  
Water Temperature ◽  
Energy Budget ◽  
Production Capacity ◽  
Short Wave ◽  
Wave Radiation ◽  
Temperature Model ◽  
Salmon River ◽  
Daily Data ◽  
Temperature Impacts

Hydro-Québec is projecting to increase the hydroelectric production capacity of the St. Marguerite River by diversion of the tributaries Pékans and Carheil rivers of the Moisie River, the most productive salmon river of the whole Quebec. Along with substantial changes in hydrological regimes, this hydroelectric development is most likely to affect some physical environment factors such as the water temperature, which is of prime importance for the biotope and, in particular, for the salmon productivity. The objective of the present study is to simulate, over a long period of time, the river water temperatures under natural conditions as compare to those after the impoundment, to assess the consequences of the tributary diversion. We used the hydrological CEQUEAU model coupled with a temperature model.The temperature model developed is applicable to the ice-free period and calculates daily water temperatures in rivers by computing an energy budget to each element of the watershed. The energy budget considers the short-wave solar radiation, long-wave radiation, evaporation, and convection in the air as well as the advective heat of various inflows from surface runoff, interflow, and groundwaters. The estimation of the atmospheric thermal exchanges is based on the equations usually found in literature. The volumes of the various inflows are given by the hydrological model. The temperature model uses daily data for air temperature and monthly data for solar radiation, cloudiness, wind speed, and vapour pressure.The model has been applied to the Moisie River (Québec), using the measured values for the calibration. Both observed and calculated values show good agreement. The model was also used to simulate, over the whole watershed, the water temperatures for the 1961–1989 period and after the diversion. The results show that the tributary diversion contributed to increase the water temperature of the Moisie River and that this increase is gradually attenuated as we progress downstream. Key words: temperature, impacts, model, Moisie, Québec, diversion, hydrology.

scholarly journals Snow cover sensitivity to black carbon deposition in the Himalayas: from atmospheric and ice core measurements to regional climate simulations

2014 ◽  
Vol 14 (8) ◽  
pp. 4237-4249 ◽  
Author(s):  
M. Ménégoz ◽  
G. Krinner ◽  
Y. Balkanski ◽  
O. Boucher ◽  
A. Cozic ◽  
...  
Keyword(s):  
Snow Cover ◽  
Black Carbon ◽  
Regional Climate ◽  
Ice Core ◽  
Ice Cores ◽  
Short Wave ◽  
Wave Radiation ◽  
The Tibetan Plateau ◽  
Snow Cover Duration ◽  
The Impact

Abstract. We applied a climate-chemistry global model to evaluate the impact of black carbon (BC) deposition on the Himalayan snow cover from 1998 to 2008. Using a stretched grid with a resolution of 50 km over this complex topography, the model reproduces reasonably well the remotely sensed observations of the snow cover duration. Similar to observations, modelled atmospheric BC concentrations in the central Himalayas reach a minimum during the monsoon and a maximum during the post- and pre-monsoon periods. Comparing the simulated BC concentrations in the snow with observations is more challenging because of their high spatial variability and complex vertical distribution. We simulated spring BC concentrations in surface snow varying from tens to hundreds of μg kg−1, higher by one to two orders of magnitude than those observed in ice cores extracted from central Himalayan glaciers at high elevations (>6000 m a.s.l.), but typical for seasonal snow cover sampled in middle elevation regions (<6000 m a.s.l.). In these areas, we estimate that both wet and dry BC depositions affect the Himalayan snow cover reducing its annual duration by 1 to 8 days. In our simulations, the effect of anthropogenic BC deposition on snow is quite low over the Tibetan Plateau because this area is only sparsely snow covered. However, the impact becomes larger along the entire Hindu-Kush, Karakorum and Himalayan mountain ranges. In these regions, BC in snow induces an increase of the net short-wave radiation at the surface with an annual mean of 1 to 3 W m−2 leading to a localised warming between 0.05 and 0.3 °C.

scholarly journals Economic and Environmental Assessment on Implementing Solar Renewable Energy Systems in Spanish Residential Homes

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4183
Author(s):  
Alberto Cerezo-Narváez ◽  
María-José Bastante-Ceca ◽  
José-María Piñero-Vilela
Keyword(s):  
Energy Efficiency ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Environmental Assessment ◽  
Hot Water ◽  
Solar Thermal ◽  
Small Scale ◽  
Gas Emissions ◽  
Energy Behavior ◽  
The Impact

In Europe, buildings are responsible for more than one third of the total final energy demands and greenhouse gas emissions. In the last twenty years, the European Union has published a succession of energy performance of building directives to define and ensure the fulfilment of a series of objectives regarding greenhouse gas emissions, energy consumption, energy efficiency and energy generation from renewable sources in buildings. For its part, Spain is adapting its legal framework, transposing these directives with the aim of achieving greater energy efficiency and sustainability for buildings. Under this context, an energy, economic and environmental assessment is performed to analyze the impact of these regulatory changes on a single-family home including a photovoltaic installation for self-consumption with surpluses and/or a solar thermal installation for domestic hot water supply, located in each one of the eight thousand one hundred thirty-one municipalities that make up Spain. The energy behavior of the original house is compared with that obtained after it is updated with these new facilities. The transient system simulation tool is used for the energy study. The results show that the European objectives are far exceeded. The energy savings achieved range from 67% to 126%, carbon dioxide emissions decrease by 42% to 100% and energy bills are reduced in cost by 32% to 81%. The findings of this work can be used by policymakers as guidelines for the development of national strategic plans and financial incentives for the promotion of small-scale residential photovoltaic and solar thermal applications, as well as by designers, supervisors, managers and developers to include them in their projects.

The Impact of Rooftop Vegetation on the UHI Phenomenon in Housing Projects: Baghdad City as an Example

2020 ◽  
Vol 5 (2) ◽  
Keyword(s):  
Short Wave ◽  
Wave Radiation ◽  
Climatic Parameters ◽  
Short Wave Radiation ◽  
Housing Projects ◽  
High Rise ◽  
Urban Heat ◽  
Almost All ◽  
Radiant Temperature ◽  
The Impact

This research investigates the impact of rooftop vegetation on the phenomenon of urban heat island (UHI) in hot-aired microclimates with an emphasis on housing projects in the context of Baghdad city. The methodology of this research relies on ENVI-met Headquarter 4.4.5 to create models that simulate and comparatively analyze the effect of rooftop vegetation on reduction UHI within housing projects. The analysis encompassed models of low-rise, mid-rise, and high-rise buildings. The simulated climatic parameters included the Predicted Mean Vote (PMV), air temperature, mean radiant temperature (MRT), reflected short-wave radiation, and humidity. The findings of this research indicated that rooftop vegetation can participate in the reduction of UHI phenomenon in housing projects, the most significant for almost all climatic parameters results were in low-rise and mid-rise buildings as compared to high-rise buildings.

Historical ablation rates and their drivers in Greenland – assessing the potential of the Wegener expedition for modern glaciological research

2020 ◽  
Author(s):  
Jakob Abermann ◽  
Wolfgang Schöner ◽  
Robert Schjøtt Fausto
Keyword(s):  
Air Temperature ◽  
Grid Point ◽  
Short Wave ◽  
Ice Age ◽  
Wave Radiation ◽  
Climate Change Signal ◽  
Horizontal Distance ◽  
West Greenland ◽  
Geometrical Change ◽  
The Impact

&lt;p&gt;Alfred Wegener contributed extraordinarily to early days of scientific explorations in Greenland. Involved in three expeditions, we present unique historical data that is stored at Graz University, where Wegener filled his last academic position until his tragic death in Greenland in 1930. In this contribution we reevaluate data from his last expedition 1929-1931 acquired at the Qaamarujuup Glacier in West Greenland (71&amp;#176;09'N; 51&amp;#176;11'W). Sub-weekly ablation measurements along with air temperature, humidity, pressure, wind and short-wave radiation data exist for two full ablation seasons both near sea level and in 950 m a.s.l.. The 20&lt;sup&gt;th&lt;/sup&gt; Century reanalysis product of the nearest grid-point performs well reproducing air temperature variability. Coincidentally, this expedition was carried out during a very warm period that was in fact comparable to recent years. We compare vertical ablation gradients from the years 1929/1930 obtained at Qaamarujuup in West Greenland with recent observations from the closest PROMICE automated weather station and discuss differences in a centennial perspective. Furthermore, we present a time-series of glacier stages from the little ice age (LIA) maximum up to present and quantify area and volume changes since. The glacier margin was in close proximity (&lt;50 m distance) to the ocean during the LIA maximum, 660 m and almost 3 km horizontal distance from the ocean in 1930 and in 2019, respectively. Such a drastic geometrical change manifests in differing drivers of the glacier boundary layer with the impact of the cooling ocean during summer decreasing with time as the glacier margin&amp;#8217;s distance to the ocean increases. We discuss the potential in using historical glacio-meteorological measurements along with a detailed glacier history in order to extract geometrical feedbacks from the climate change signal.&lt;/p&gt;

The influence of radiative forcing on permafrost temperatures in Arctic rock walls

2020 ◽  
Author(s):  
Juditha Schmidt ◽  
Sebastian Westermann ◽  
Bernd Etzelmüller ◽  
Florence Magnin
Keyword(s):  
Solar Radiation ◽  
Short Wave ◽  
Latitudinal Gradients ◽  
Wave Radiation ◽  
Strong Impact ◽  
Permafrost Degradation ◽  
Long Wave ◽  
Hourly Data ◽  
Set Up ◽  
Long Wave Radiation

&lt;p&gt;Climate change has a strong impact on periglacial regions and intensifies the degradation of mountain permafrost. This can result in instabilities of steep rock walls as rock- and ice-mechanical properties are modified. Besides altitude and the related air temperature, latitude is a crucial factor, as solar radiation has a strong impact on the energy transfer processes from the atmosphere to the ground. It can differ significantly in intensity and time over latitudinal positions and exposures of frozen rock slopes.&lt;/p&gt;&lt;p&gt;In this project, we suggest improving the parametrization of short-wave and long-wave radiation in thermal models for permafrost degradation. To achieve this, we will analyze temperature data of surface temperature loggers from Southern Norway to Svalbard. In total, 37 loggers were installed between 2010 and 2017. The field sites display enormous latitudinal gradients as well as topographic settings. Furthermore, they provide hourly data, allowing us to set up short-stepped time series for examination of solar radiation angles at varying latitudes.&lt;/p&gt;&lt;p&gt;The data is used to set up a transient heat-flow model (CryoGrid) to simulate the local thermal regime. The model takes into account varying input of short-wave radiation due to aspect, slope angle and time as well as long-wave radiation under different sky-view factors. Finally, the influence of solar radiation on permafrost degradation in steep rock walls is investigated.&lt;/p&gt;

scholarly journals The impact of the transition of hot water “preparation” by means of individual heating stations on the Kazan energy system

2019 ◽  
Vol 124 ◽  
pp. 05012
Author(s):  
I.N. Zapolskaya ◽  
Yu.V. Vankov ◽  
O.I. Zverev ◽  
R.R. Rotach
Keyword(s):  
Water Supply ◽  
Economic Effect ◽  
Energy System ◽  
Supply System ◽  
Hot Water ◽  
Water Supply Systems ◽  
Main Task ◽  
Apartment Buildings ◽  
Hot Water Supply ◽  
The Impact

The result of the implementation of technical solutions should be evaluated in terms of the effect on the power system as a whole. At the same time, the main task is to obtain a socio-economic effect noticeable for the consumer of energy resources, as he is a key figure of the energy system. The article considers the influence of modernization of hot water supply systems (HWS) by transferring the function of hot water preparation in apartment buildings to individual heating stations (IHS) from the district heating stations (DHS) with their subsequent liquidation, as well as the elimination of hot water supply grid. The expected result of these measures is the reduction in heat energy loss in heat carrier agents in heating networks, as well as improving the quality and reliability of the hot water supply system and the possible reduction of energy consumption by residents in apartment buildings. The effect on the operation of the heat supply system will not be provided by IHSs themselves, but by automatic controllers, installed together with them. This, in turn, will make it possible for the Central Heating and Power plants (boiler) to be modernized in operation in a timely manner, to improve the system’s efficiency. Computational studies were carried out in order to assess the impact of the transition from IHS to hot water supply on the energy system.

scholarly journals Impact of Lightning NOx Emissions on Atmospheric Composition and Meteorology in Africa and Europe

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1128
Author(s):  
Laurent Menut ◽  
Bertrand Bessagnet ◽  
Sylvain Mailler ◽  
Romain Pennel ◽  
Guillaume Siour
Keyword(s):  
Surface Flux ◽  
Short Wave ◽  
Atmospheric Composition ◽  
Wave Radiation ◽  
Nox Emissions ◽  
Large Area ◽  
Convective Clouds ◽  
Pollutant Concentrations ◽  
The Impact ◽  
Lightning Nox

NOx emissions from lightning have been added to the CHIMERE v2020r1 model using a parameterization based on convective clouds. In order to estimate the impact of these emissions on pollutant concentrations, two simulations, using the online coupled WRF-CHIMERE models with and without NOx emissions from lightning, have been carried out over the months of July and August 2013 and over a large area covering Europe and the northern part of Africa. The results show that these emissions modify the pollutant concentrations as well as the meteorology. The changes are most significant where the strongest emissions are located. Adding these emissions improves Aerosol Optical Depth in Africa but has a limited impact on the surface concentrations of pollutants in Europe. For the two-month average we find that the maximum changes are localized and may reach ±0.5 K for 2 m temperature, ±0.5 m s−1 for 10 m wind speed, 10 W m−2 for short wave radiation surface flux, and 50 and 2 μg m−3 for dust and sea salt surface concentrations, respectively. This leads to maximum changes of 1 μg m−3 for surface concentrations of PM2.5.

scholarly journals Observational evaluation of outdoor cooling potential of air-source heat pump water heaters

2021 ◽  
Author(s):  
Kazuki Yamaguchi ◽  
Tomohiko Ihara ◽  
Yukihiro Kikegawa
Keyword(s):  
Wind Speed ◽  
Heat Pump ◽  
Thermal Environment ◽  
Hot Water ◽  
Influential Factor ◽  
Water Supply Systems ◽  
Outdoor Air ◽  
Water Heaters ◽  
Air Source Heat Pump ◽  
The Impact

Abstract Heat pump water heaters are highly efficient hot water supply systems that effectively utilize the heat of outdoor air via heat pump technology. Many studies have been conducted to optimize the design and operation of heat pump water heaters from the perspective of climate change mitigation. Air-source heat pump water heaters, which absorb heat from the outdoor air and emit cold exhaust, can also be expected to alleviate the urban heat island effect; however, this has not been studied extensively. To estimate the impact of cold exhaust on building-scale climate, we conducted a multipoint measurement of the outdoor thermal environment around a low-rise apartment building equipped with air-source heat pump water heaters, in both summer and winter. Observations showed a substantial cooling effect that decreased air temperatures by 1°C within the site boundary on summer nights when multiple heat pump water heaters operated concurrently. The analysis revealed that the sensitivity of the ambient temperatures to cold exhaust depends strongly on local atmospheric conditions. The most influential factor was the wind direction: the sensitivity increased significantly when the exhaust outlet location was at the lee side of the building. Naturally, the wind speed also affected the sensitivity, which tended to be higher when the wind speed was lower. The convective stability near the ground surface, however, showed no significant influence over the sensitivity.

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