A method for operating a solar thermal system. The method includes providing a photovoltaic apparatus coupled to a solar thermal apparatus. In a preferred embodiment, the solar thermal apparatus comprises flow region having a first measurement region and a second measurement region. The first measurement region is configured by a spatial distance to the second measurement region according to one or more embodiments. The present method also includes receiving electrical information associated with operation of the photovoltaic apparatus and receiving thermal information associated with operation of the solar thermal apparatus. In a specific embodiment, the thermal information is derived from the first measurement region and the second measurement region. The method also includes processing the electrical information and associating the electrical information against one or more electrical parameters and processing the thermal information and associating the thermal information against one or more thermal parameters. In a preferred embodiment, the method associates the one or more thermal parameters with the one or more electrical parameters to determine a state (e.g., failure, working, maintenance) of the solar thermal apparatus.