Investigation of City-Level Site-Pair Correlations of Solar Variability using Empirical Satellite Data

The paper discusses solar resource variability and geographic smoothing at a city-level by estimating the site-pair correlations of solar variability. The site-pair correlation of solar variability, ρ
_ΔKt
, is quantified by estimating the correlation between the changes in clear-sky indices, ΔKt, of a pair of sites. The paper studies the variation of ρ
_ΔKt
with a) the distance between the sites, and b) both the distance between the sites and the difference between the relative humidity profiles of the sites. The study has been conducted for three Indian cities - Mumbai, Delhi and Bengaluru - on hourly radiation and climatic data spread over a span of five years, 2010 - 2014.