Energy demand is increasing while we are facing a depletion of fossils fuels, the main source of energy production in the world. These last years, photovoltaic (PV) system technologies are growing rapidly among altern...Energy demand is increasing while we are facing a depletion of fossils fuels, the main source of energy production in the world. These last years, photovoltaic (PV) system technologies are growing rapidly among alternative sources of energy to contribute to mitigation of climate change. However, PV system efficiency researches operating under West African weather conditions are nascent. The first objective of this study is to investigate the sensitivity of common monocrystalline PV efficiency to local meteorological parameters (temperature, humidity, solar radiation) in two contrasted cities over West Africa: Niamey (Niger) in a Sahelian arid area and Abidjan (Cote d’Ivoire) in atropical humid area. The second objective is to quantify the effect of dust accumulation on PV efficiency in Niamey (Niger). The preliminary results show that PV efficiency is more sensitive to high temperature change especially under Niamey climate conditions (warmer than Abidjan) where high ambient temperatures above 33°C lead to an important decrease of PV efficiency. Increase of relative humidity induces a decrease of PV efficiency in both areas (Niamey and Abidjan). A power loss up to 12.46% is observed in Niamey after 21 days of dust accumulation.展开更多
<span style="font-family:Verdana;">Thermal comfort is one of the most important requirements that scientists and building designers must meet to ensure the indoor air quality knowing its importance on ...<span style="font-family:Verdana;">Thermal comfort is one of the most important requirements that scientists and building designers must meet to ensure the indoor air quality knowing its importance on productivity and the health of occupants. However, it has never been of great concern for architects and architectural historians and seldom explores it. Buildings are the large consumer of the most energy consumption (around 40% worldwide) and generate around 35% of GHGs like CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> that leads to extreme climate change. Hence, general and specific eco-friendly solutions in the field of building construction are required. Analysis of this study shows that air conditioning consumption can be significantly reduced thanks to the compressed earth bricks and by taking into account the climate and the orientation of the facades. However, this paper establishes viable low-cost option of building energy consumption while maintaining the thermal comfort and good indoor air quality. This work explains the effect of a single residential room orientation, by reducing </span><span style="font-family:Verdana;">the thermal amplitude, and improving the thermal phase shift in Ouagadougou</span><span style="font-family:Verdana;"> climate conditions in April. Internal temperature was modelled with 8 cardinal orientations. The result corresponds to a decrease of thermal amplitude </span><span style="font-family:Verdana;">damping greater than 4<span style="white-space:nowrap;">°</span>C between East-West and North-South sides and, with a thermal phase shift of 4</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">hours</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">30</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">minutes between the Nord and West walls.</span>展开更多
The sensitivity of mono-crystalline solar PV module towards dust accumulation, ambient temperature, relative humidity, and cloud cover is investigated from May to August 2015 for Niamey’s environment. Two solar modul...The sensitivity of mono-crystalline solar PV module towards dust accumulation, ambient temperature, relative humidity, and cloud cover is investigated from May to August 2015 for Niamey’s environment. Two solar modules with the same characteristics have been used to carry out the impacts of the dust on the solar PV module. One of the modules is being cleaned every morning and the second one was used for monitoring the effect of dust accumulation onto the surface of the unclean module for May and June. The ambient temperature around the solar PV module was recorded at the same time with the output voltage and the output current to assess the impacts of ambient temperature on the PV conversion efficiency. In addition to these field test measurements, the solar radiation data measured in National Center of Solar Energy (CNES) of Niamey were also used. Also the relative humidity for the study area data obtained NASA power agro-climatology website was used. Results show that the dust accumulation has the greatest impact on the performance of the PV module followed by temperature, relative humidity and cloud cover. Exposing the module in 23 days has reduced the energy output by 15.29%. The power output and the conversion efficiency of the PV module have dropped by 2.6% and 0.49% respectively. The relative humidity also has reduced the energy output by 4.3 Wh/m2/day.展开更多
文摘Energy demand is increasing while we are facing a depletion of fossils fuels, the main source of energy production in the world. These last years, photovoltaic (PV) system technologies are growing rapidly among alternative sources of energy to contribute to mitigation of climate change. However, PV system efficiency researches operating under West African weather conditions are nascent. The first objective of this study is to investigate the sensitivity of common monocrystalline PV efficiency to local meteorological parameters (temperature, humidity, solar radiation) in two contrasted cities over West Africa: Niamey (Niger) in a Sahelian arid area and Abidjan (Cote d’Ivoire) in atropical humid area. The second objective is to quantify the effect of dust accumulation on PV efficiency in Niamey (Niger). The preliminary results show that PV efficiency is more sensitive to high temperature change especially under Niamey climate conditions (warmer than Abidjan) where high ambient temperatures above 33°C lead to an important decrease of PV efficiency. Increase of relative humidity induces a decrease of PV efficiency in both areas (Niamey and Abidjan). A power loss up to 12.46% is observed in Niamey after 21 days of dust accumulation.
文摘<span style="font-family:Verdana;">Thermal comfort is one of the most important requirements that scientists and building designers must meet to ensure the indoor air quality knowing its importance on productivity and the health of occupants. However, it has never been of great concern for architects and architectural historians and seldom explores it. Buildings are the large consumer of the most energy consumption (around 40% worldwide) and generate around 35% of GHGs like CO</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> that leads to extreme climate change. Hence, general and specific eco-friendly solutions in the field of building construction are required. Analysis of this study shows that air conditioning consumption can be significantly reduced thanks to the compressed earth bricks and by taking into account the climate and the orientation of the facades. However, this paper establishes viable low-cost option of building energy consumption while maintaining the thermal comfort and good indoor air quality. This work explains the effect of a single residential room orientation, by reducing </span><span style="font-family:Verdana;">the thermal amplitude, and improving the thermal phase shift in Ouagadougou</span><span style="font-family:Verdana;"> climate conditions in April. Internal temperature was modelled with 8 cardinal orientations. The result corresponds to a decrease of thermal amplitude </span><span style="font-family:Verdana;">damping greater than 4<span style="white-space:nowrap;">°</span>C between East-West and North-South sides and, with a thermal phase shift of 4</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">hours</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">30</span><span style="font-family:;" "=""> </span><span style="font-family:Verdana;">minutes between the Nord and West walls.</span>
文摘The sensitivity of mono-crystalline solar PV module towards dust accumulation, ambient temperature, relative humidity, and cloud cover is investigated from May to August 2015 for Niamey’s environment. Two solar modules with the same characteristics have been used to carry out the impacts of the dust on the solar PV module. One of the modules is being cleaned every morning and the second one was used for monitoring the effect of dust accumulation onto the surface of the unclean module for May and June. The ambient temperature around the solar PV module was recorded at the same time with the output voltage and the output current to assess the impacts of ambient temperature on the PV conversion efficiency. In addition to these field test measurements, the solar radiation data measured in National Center of Solar Energy (CNES) of Niamey were also used. Also the relative humidity for the study area data obtained NASA power agro-climatology website was used. Results show that the dust accumulation has the greatest impact on the performance of the PV module followed by temperature, relative humidity and cloud cover. Exposing the module in 23 days has reduced the energy output by 15.29%. The power output and the conversion efficiency of the PV module have dropped by 2.6% and 0.49% respectively. The relative humidity also has reduced the energy output by 4.3 Wh/m2/day.