Solar Irradiance was computed as the output of an open-source shading model that can be applied in the SAGA GIS software package. The model takes a digital elevation model as input and simulates direct and diffuse solar irradation on a surface over time. The model considers climate, atmospheric conditions, and the sun's shifting positions in the sky. For computational tractability, this model was fit for the duration of March 1 to March 31, 2017. The digital elevation model was generated using GMTED2010 (Global Multi-resolution Terrain Elevation Data), which is freely available with global coverage at 30 square meter resolutions. A more precise model could be trained with Lidar data of 1 square meter resolution. Given the course elevation model input, the kWh/m2 estimates are likely undervalued compared to ground truth.
The maps above show aggregate statistics of solar irradiance at the village tract level.