Certain example embodiments relate to a glazing assembly including a first glass substrate. A radiation shield covering, directly or indirectly, at least a part of a peripheral edge area of the first glass substrate. A dual junction solid-state heat flux sensor includes a first junction oriented in the assembly at a first location at which radiation from a radiation source is receivable through the first glass substrate; a second junction oriented in the assembly at a second location that is blocked from the radiation source by the radiation shield; and circuitry configured to generate a signal based on a differential between transduced voltages respectively generated at the first and second junctions. A control module may be configured to receive the signal and selectively generate an action responsive thereto.