The moon, a street light or even a floodlight fairly near isn't going to produce enough voltage in a
solar panel. Sunlight is around 1000 watts per square metre.
Solar panels are about 17% efficient, so a 100W panel is about 0.6 square metres.
If you allow for the light to be a fifth of that power (the least that is worth bothering with), that's 200 watts per square metre or 120 onto a 100 watt panel.
So you'd need a 500W security lamp to be 25% efficient (they are under 20% in reality) and set up so that ALL its light shines onto your panel: none wasted. Ain't gonna happen, unfortunately.
And anything less bright, no chance.