Inferring PV System Specifications from Net Load

The increasing penetration of grid-connected solar photovoltaics (PV) has challenged the existing method of planning and operating the distribution grid. Electric utilities increasingly require visibility on the Behind- The-Meter (BTM) PV installations within their territories. They are interested in knowing the physical characteristics of the installed PV systems as well as their energy production profiles. This paper provides a novel method to infer the azimuth, tilt, and size of a PV system using only net load data and PV system location. Net load (total load minus PV production) represents the combined effect of consumption and PV system production. Our method utilizes Solar Anywhere® to produce plane of array irradiance for various azimuth and tilt combinations which serves as the ground truth data. The optimal PV system specification for each individual PV system is inferred by matching characteristics derived from net load data to the ones derived from the ground truth data. The proposed method is demonstrated on a test site in California and then implemented for all residential PV systems in a utility’ service territory. All locations have both net load and PV production data. We use the net load data to infer the system specifications and then the PV production data to validate the method’ accuracy.