**Validation of All-Sky Imager Technology and Solar Irradiance Forecasting at Three Locations: NREL, San Antonio, Texas, and the Canary Islands, Spain**

**Walter Richardson Jr. 1,\*, David Cañadillas 2, Ariana Moncada 1, Ricardo Guerrero-Lemus 2, Les Shephard 3, Rolando Vega-Avila <sup>4</sup> and Hariharan Krishnaswami <sup>5</sup>**


Received: 30 December 2018; Accepted: 8 February 2019; Published: 17 February 2019
