Impact of the 4 April 2014 Saharan dust outbreak on the photovoltaic power generation in Germany

Abstract

Abstract. The importance for reliable forecasts of incoming solar radiation is growing rapidly, especially for those countries with an increasing share in photovoltaic (PV) power production. The reliability of solar radiation forecasts depends mainly on the representation of clouds and aerosol particles absorbing and scattering radiation. Especially under extreme aerosol conditions, numerical weather prediction has a systematic bias in the solar radiation forecast. This is caused by the design of numerical weather prediction models, which typically account for the direct impact of aerosol particles on radiation using climatological mean values and the impact on cloud formation assuming spatially and temporally homogeneous aerosol concentrations. These model deficiencies in turn can lead to significant economic losses under extreme aerosol conditions. For Germany, Saharan dust outbreaks occurring 5 to 15 times per year for several days each are prominent examples for conditions, under which numerical weather prediction struggles to forecast solar radiation adequately. We investigate the impact of mineral dust on the PV-power generation during a Saharan dust outbreak over Germany on 4 April 2014 using ICON-ART, which is the current German numerical weather prediction model extended by modules accounting for trace substances and related feedback processes. We find an overall improvement of the PV-power forecast for 65 % of the pyranometer stations in Germany. Of the nine stations with very high differences between forecast and measurement, eight stations show an improvement. Furthermore, we quantify the direct radiative effects and indirect radiative effects of mineral dust.For our study, direct effects account for 64 %, indirect effects for 20 % and synergistic interaction effects for 16 % of the differences between the forecast including mineral dust radiative effects and the forecast neglecting mineral dust.

Effects of Particle Nonsphericity on Dust Optical Properties in a Forecast System: Implications for Model‐Observation Comparison

“…The calculation of the optical properties is based on the wavelength-dependent refractive indices of dust used by Rieger et al (2017), which is in good agreement (difference <5% in the shortwave) with the recent dust refractive index databases for North Africa (Stegmann & Yang, 2017). For spherical particles, the results of the Mie calculations conducted by Gasch et al (2017) are used.…”

Solar Energy Estimations in India Using Remote Sensing Technologies and Validation with Sun Photometers in Urban Areas

“…Aerosols made up of dust, smoke particles, haze, and small water droplets cause scattering of SR, which varies depending upon the actual atmospheric conditions. In certain cases, aerosol can cause 80% reduction in SR, as shown in [46,[90][91][92][93]. Under clear-sky conditions, when the atmosphere is free of clouds, aerosols play an important role in the transfer of SR.…”

A Process Study on Thinning of Arctic Winter Cirrus Clouds With High‐Resolution ICON‐ART Simulations

“…Keeping the standard deviations i constant during the simulation, the modes' mean diameter is a diagnostic variable being able to change due to aerosol dynamical processes like sedimentation, dry deposition, and washout. A detailed description of parameterizations for mineral dust emission can be found in Rieger et al (2017). The emission fluxes of sea salt aerosol are calculated online depending on wind speed and temperature (Lundgren et al, 2013).…”

“…The radiative fluxes in ICON-ART are calculated using the Rapid Radiative Transfer Model (RRTM) (Mlawer et al, 1997). The interactions of mineral dust and sea salt with the radiative fluxes realized in ICON-ART are described in detail in Rieger et al (2017) and Gasch et al (2017). To account for the impact of hydrometeors on radiation, cloud optical properties are calculated based on the effective radius (r e ) following Stevens et al (2013).…”