An Unsupervised Method for Estimating the Global Horizontal Irradiance from Photovoltaic Power Measurements

摘要

In this paper, we present a method to determine the global horizontalirradiance (GHI) from the power measurements of one or more PV systems, locatedin the same neighborhood. The method is completely unsupervised and is based ona physical model of a PV plant. The precise assessment of solar irradiance ispivotal for the forecast of the electric power generated by photovoltaic (PV)plants. However, on-ground measurements are expensive and are generally notperformed for small and medium-sized PV plants. Satellite-based servicesrepresent a valid alternative to on site measurements, but their space-timeresolution is limited. Results from two case studies located in Switzerland arepresented. The performance of the proposed method at assessing GHI is comparedwith that of free and commercial satellite services. Our results show that thepresented method is generally better than satellite-based services, especiallyat high temporal resolutions.