It should be possible to determine what portion of the day bright sunshine is possible within. At the very least, constrain between dawn and dusk. This will reduce number of sensor readings, and thus energy consumption, and also facilitate earlier reporting of daily averages.
Found a very low power Ambient & UV sensor that can trigger interrupts - could potentially be "always on" and when interrupt is triggered update the thresholds to next lighting level boundaries.
It should be possible to determine what portion of the day bright sunshine is possible within. At the very least, constrain between dawn and dusk. This will reduce number of sensor readings, and thus energy consumption, and also facilitate earlier reporting of daily averages.