Development of clear sky models, impact assessment of short-term temporal variability of solar power and day-ahead prognosis of solar irradiance in Rajasthan
Student name: Mr Sujit Kumar Tripathy
Guide: Dr B Prasad
Year of completion: 2015
Host Organisation: Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH, New Delhi
Supervisor (Host Organisation): Dr Indradip Mitra
Abstract: In 2010, National Institute of Wind Energy (NIWE), Chennai, an autonomous R&D institution
functioning under the aegis of MNRE, GOI, had embarked on a journey to set up solar radiation
resource assessment (SRRA) stations all over India. As of April 2015, 121 SRRA stations are
dispersed across the length and breadth of our country, constituting the world’s largest network of
solar radiation measurement stations. Everyday millions of data points quantifying global, direct and
diffuse irradiance are acquired at SRRA stations and stored at Central Receiving Station (CRS)
established at NIWE. These measured data points go through a rigorous quality control (QC) in
accordance to baseline surface radiation rules of World meteorological Organization (WMO). Clear
sky models by Iqbal and Bird are used extensively for the quality control procedure.
This report provides an overview on the Bird, Iqbal global horizontal irradiance (GHI) clear sky
models. Iqbal model estimates the terrestrial solar radiation under a cloudless sky as a function of
solar elevation angle, site altitude, Raleigh scattering and various atmospheric conditions, while
Bird model considers additional parameters such as aerosol concentration, water vapour column etc.
Also, a Matlab based advanced clear sky GHI calculator (Implementing Bird, Iqbal models and
hybrid model of both) has been developed and discussed here.Key Words: Clear Sky Model, Bird Model, Iqbal Model, Hybrid Model, Solar Position.
