Correcting satellite derived DNI with systematic and seasonal deviations: Application to India

Abstract

a b s t r a c tA simple method for correcting satellite-derived direct normal irradiance, with important deviations to the experimental data, is presented in this work and illustrated for the particular case of Rajasthan (India). Northwest India is expected to have a high level of solar radiation and it is an interesting area for solar concentrating power systems. However uncertainty in direct normal irradiance estimations from satellite may affect negatively to the bankability of solar plants. Direct normal irradiance have been estimated for a site in Rajasthan from satellite information for the period 2003 to 2011, and ground measurements during 2011 have been used to analyze the uncertainties and to develop a simple correction method. The original satellite estimations showed important deviations from the experimental values and high bias. A systematic underestimation of direct irradiance has been observed during the dryer seasons that could be attributed to an overestimation of the aerosol optical depth input to the model. These observations have allowed the design of a correction methodology. Unbiased new estimations of direct normal irradiance have been generated with this methodology with important reduction in the deviations and with an agreement in the distribution functions compared to the distribution function of the ground data.

Validation of Hourly Global Horizontal Irradiance for Two Satellite-Derived Datasets in Northeast Iraq

“…Those rates are quite reasonable for hourly GHI [42]. Those rates of bias can be corrected or modified in some ways [14,18,56,57].…”

“…This indicates that the GHI ground data are well explained by the SDDs in clear-sky conditions, whereas they are not explained well in cloudy-sky conditions ( Figures S6-S15). The results of high bias and RMSE indicate that further research is required to correct the errors under cloudy-sky conditions, whereas several studies have done bias corrections for all-sky conditions [14,18,56,57].…”

Concentrated solar power technology in India: A review

“…For concentration, most systems use glass mirrors because of their very high reflectivity. Sun tracking system is also required to align the beam radiation on the receiver [19]. CSP based systems concentrate the direct normal radiation of the sun on an area called receiver which is designed to absorb maximum radiation falling on it [20].…”

Solar global horizontal and direct normal irradiation maps in Spain derived from geostationary satellites

“…However, under clear sky conditions the inaccuracy in the determination of the aerosol loads (an even other atmospheric constituents) can have an important contribution to the model retrievals (Gueymard, 2011;Gueymard, 2012;Gueymard, 2014). The use of high quality ground data in hourly basis of the measured solar radiation components can allow for improvement of the satellite-based models, by reducing the bias or even systematic errors, that could result in more accurate mapping of the solar resource in a region (Cebecauer and Suri, 2012;Mieslinger et al, 2014;Polo et al, 2015).…”