scholarly journals Long-term variability of solar irradiance and its implications for photovoltaic power in West Africa

2020 ◽  
Author(s):  
Ina Neher ◽  
Susanne Crewell ◽  
Stefanie Meilinger ◽  
Uwe Pfeifroth ◽  
Jörg Trentmann
Keyword(s):  
West Africa ◽  
Power Systems ◽  
Solar Irradiance ◽  
Positive Trend ◽  
Wet Season ◽  
Regional Variability ◽  
Surface Solar Radiation ◽  
Data Set ◽  
Photovoltaic Power

Abstract. This paper addresses long-term changes in solar irradiance for West Africa (3° N to 20° N and 20° W to 16° E) and its implications for photovoltaic power systems. Here we use satellite irradiance (Surface Solar Radiation Data Set-Heliosat, Edition 2.1, SARAH-2.1) to derive photovoltaic yields. Based on 35 years of data (1983–2017) the temporal and regional variability as well as long-term trends of global and direct horizontal irradiance are analyzed. Furthermore, at four locations a detailed time series analysis is undertaken. The dry and the wet season are considered separately. According to the high resolved SARAH-2.1 data record (0.05° x 0.05°), solar irradiance is largest (with up to 300 W/m² daily average) in the Sahara and the Sahel zone with a positive trend (up to 5 W/m²/decade) and a lower variability (

scholarly journals Photovoltaic power potential in West Africa using long-term satellite data

2020 ◽  
Vol 20 (21) ◽  
pp. 12871-12888
Author(s):  
Ina Neher ◽  
Susanne Crewell ◽  
Stefanie Meilinger ◽  
Uwe Pfeifroth ◽  
Jörg Trentmann
Keyword(s):  
West Africa ◽  
Temporal Variability ◽  
Solar Irradiance ◽  
Negative Trend ◽  
Positive Trend ◽  
Wet Season ◽  
Regional Variability ◽  
Surface Solar Radiation ◽  
Data Set

Abstract. This paper addresses long-term historical changes in solar irradiance in West Africa (3 to 20∘ N and 20∘ W to 16∘ E) and the implications for photovoltaic systems. Here, we use satellite irradiance (Surface Solar Radiation Data Set – Heliosat, Edition 2.1 – SARAH-2.1) and temperature data from a reanalysis (ERA5) to derive photovoltaic yields. Based on 35 years of data (1983–2017), the temporal and regional variability as well as long-term trends in global and direct horizontal irradiance are analyzed. Furthermore, a detailed time series analysis is undertaken at four locations. According to the high spatial resolution SARAH-2.1 data record (0.05∘×0.05∘), solar irradiance is largest (up to a 300 W m−2 daily average) in the Sahara and the Sahel zone with a positive trend (up to 5 W m−2 per decade) and a lower temporal variability (<75 W m−2 between 1983 and 2017 for daily averages). In contrast, the solar irradiance is lower in southern West Africa (between 200 W m−2 and 250 W m−2) with a negative trend (up to −5 W m−2 per decade) and a higher temporal variability (up to 150 W m−2). The positive trend in the north is mostly connected to the dry season, whereas the negative trend in the south occurs during the wet season. Both trends show 95 % significance. Photovoltaic (PV) yields show a strong meridional gradient with the lowest values of around 4 kWh  kWp−1 in southern West Africa and values of more than 5.5 kWh  kWp−1 in the Sahara and Sahel zone.

scholarly journals Long-term variability of solar irradiance and its implications for photovoltaic power in West Africa

2020 ◽  
Author(s):  
Ina Neher ◽  
Susanne Crewell ◽  
Stefanie Meilinger ◽  
Uwe Pfeifroth ◽  
Jörg Trentmann
Keyword(s):  
West Africa ◽  
Solar Irradiance ◽  
Dry Season ◽  
Negative Trend ◽  
Annual Data ◽  
Positive Trend ◽  
Data Set ◽  
Data Record ◽  
The Impact

&lt;p&gt;&lt;span&gt;&lt;span&gt;West Africa is one of the least developed regions in the world regarding the energy availability and energy security. Located close to the equator West Africa receives high amounts of global horizontal irradiance (GHI). Thus, solar power and especially photovoltaic (PV) systems seem to be a promising solution to provide electricity with low environmental impact. To plan and to dimension a PV power system climatological data for global horizontal irradiance (GHI) and its variability need to be taken into account. However, ground based measurements of irradiances are not available continuously and cover only a few discrete locations.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;&lt;span&gt;Data records of surface irradiance based on satellite measurements have the advantage of covering wide spatial regions and being available over long time periods. The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) Satellite Application Facility on Climate Monitoring (CM SAF) provides the Surface Solar Radiation Data Set-Heliosat, Edition 2.1 (SARAH-2.1), a 35 year long climate data record in an half hourly resolution, covering the whole of Africa and Europe.&lt;br&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;&lt;span&gt;In this study, the SARAH-2.1 data record (1983-2017) is used to analyze the impact of 35 years atmospheric variability and trend on GHI and PV yields over West Africa (defined as the region from 3&amp;#176;N to 20&amp;#176;N and 20&amp;#176;W to 16&amp;#176;E). The trend and the variability of solar irradiance is analyzed separately for the wet and dry season as well as for annual data. Furthermore, a simplified model provides high-resolution potential PV yields. &lt;/span&gt;&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;&lt;span&gt;According to the SARAH-2.1 data record, solar irradiance is largest (with up to 300 W/m 2 daily average) in the Sahara and the Sahel zone with a positive trend (up to 5 W/m&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span&gt;&lt;span&gt;2&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;span&gt;&lt;span&gt;/decade). Whereas, the solar irradiance is lower in southern West Africa with a negative trend (up to -5 W/m&lt;/span&gt;&lt;/span&gt;&lt;sup&gt;&lt;span&gt;&lt;span&gt;2&lt;/span&gt;&lt;/span&gt;&lt;/sup&gt;&lt;span&gt;&lt;span&gt;/decade). The positive trend is mostly connected to the dry season, while the negative trend occurs during the wet season. PV yields show a strong meridional gradient with lowest values around 4 kWh/kWp in southern West Africa and reach more than 5 kWh/kWp in the Sahara and Sahel zone.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;&lt;p&gt;&lt;span&gt;&lt;span&gt;T&lt;/span&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;his poster will discuss the long-term trend and variability analysis of solar irradiance and highlight the implications for photovoltaic-based power systems in West Africa.&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;

scholarly journals Two years of Ozone radio soundings over Cotonou as part of AMMA: overview

2009 ◽  
Vol 9 (3) ◽  
pp. 11221-11268 ◽  
Author(s):  
V. Thouret ◽  
M. Saunois ◽  
A. Minga ◽  
A. Mariscal ◽  
B. Sauvage ◽  
...  
Keyword(s):  
West Africa ◽  
Biomass Burning ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
Data Sets ◽  
Wet Season ◽  
Data Set ◽  
In Situ Data ◽  
Multidisciplinary Analysis ◽  
First Time

Abstract. As part of the African Monsoon Multidisciplinary Analysis (AMMA) program, a total of 98 ozone vertical profiles over Cotonou, Benin, have been measured during a 26 month period (December 2004–January 2007). These regular measurements broadly document the seasonal and inter annual variability of ozone in both the troposphere and the lower stratosphere over West Africa for the first time. This data set is complementary to the MOZAIC observations made from Lagos between 0 and 12 km during the period 1998–2004. Both data sets highlight the unique way in which West Africa is impacted by two biomass burning seasons: in December–February (dry season) due to burning in the Sahelian band and in June–August (wet season) due to burning in southern Africa. High inter annual variabilities between Cotonou and Lagos data sets and within each data set are observed and are found to be a major characteristic of this region. In particular, the dry and wet seasons are discussed in order to set the data of the Special Observing Periods (SOPs) into a climatological context. Compared to other dry and wet seasons, the dry and wet season campaigns took place in rather high ozoneenvironments. During the sampled wet seasons, southern intrusions of biomass burning were particularly frequent with concentrations up to 120 ppbv of ozone in the lower troposphere. An insight into the ozone distribution in the upper troposphere and the lower stratosphere (up to 26 km) is given. The first tropospheric columns of ozone based on in-situ data in this region are assessed. They compare well with satellite products on seasonal and inter annual time-scales, provided that the layer below 850 Pa where the remote instrument is less sensitive to ozone, is removed.

scholarly journals An overview of two years of ozone radio soundings over Cotonou as part of AMMA

2009 ◽  
Vol 9 (16) ◽  
pp. 6157-6174 ◽  
Author(s):  
V. Thouret ◽  
M. Saunois ◽  
A. Minga ◽  
A. Mariscal ◽  
B. Sauvage ◽  
...  
Keyword(s):  
West Africa ◽  
Biomass Burning ◽  
Lower Stratosphere ◽  
Lower Troposphere ◽  
Data Sets ◽  
Wet Season ◽  
Data Set ◽  
In Situ Data ◽  
Multidisciplinary Analysis ◽  
First Time

Abstract. As part of the African Monsoon Multidisciplinary Analysis (AMMA) program, a total of 98 ozone vertical profiles over Cotonou, Benin, have been measured during a 26 month period (December 2004–January 2007). These regular measurements broadly document the seasonal and interannual variability of ozone in both the troposphere and the lower stratosphere over West Africa for the first time. This data set is complementary to the MOZAIC observations made from Lagos between 0 and 12 km during the period 1998–2004. Both data sets highlight the unique way in which West Africa is impacted by two biomass burning seasons: in December–February (dry season) due to burning in the Sahelian band and in June-August (wet season) due to burning in southern Africa. High interannual variabilities between Cotonou and Lagos data sets and within each data set are observed and are found to be a major characteristic of this region. In particular, the dry and wet seasons are discussed in order to set the data of the Special Observing Periods (SOPs) into a climatological context. Compared to other dry and wet seasons, the 2006 dry and wet season campaigns took place in rather high ozone environments. During the sampled wet seasons, southern intrusions of biomass burning were particularly frequent with concentrations up to 120 ppbv of ozone in the lower troposphere. An insight into the ozone distribution in the upper troposphere and the lower stratosphere (up to 26 km) is given. The first tropospheric columns of ozone based on in-situ data over West Africa are assessed. They compare well with satellite products on seasonal and interannual time-scales, provided that the layer below 850 hPa where the remote instrument is less sensitive to ozone, is removed.

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