High resolution characterisation of solar variability for two sites in Eastern Canada

The characterisation of solar resource variability is important to understanding the impacts of PV grid-integration. A total of 41 monitoring units were distributed at two sites in Eastern Canada, collecting irradiance data with a recording period of 10 ms. The solar variability was quantified using the Variability Index and distribution using the daily Clear-Sky Index, allowing grouping of the days measured at each site into four discrete categories. The Variability Score was also computed to facilitate comparisons with other similarly characterised sites. The effect of recording period on these metrics suggests that using a recording period longer than 400 ms would lead to underestimating variability in many cases. The dependence of observed variability on geographic dispersion is also examined, demonstrating a relationship between cloud speed, footprint area, and the averaged Variability Index.