Moon-reactive street-light

These winter months, I am walking home in darkness from college. There is one particular patch on my walk which is quite precarious as it is outside a building site. The rest of my route is well-lit. So I particularly notice when the moon is out because a full, bright moon makes this section of my walk easy to navigate.

Streetlights can turn on/off in daylight when they are not needed. Why couldn't streetlights turn off at night time too - on those nights that are illuminated by the moon? How much energy would be saved? Surely a minimum of 12 nights per year, i.e. 1/40th. But every watt of energy saved is a drop of oil still in the ground or an ounce less carbon in the atmosphere, eh?

So for the purposes of this blog, I did a bit of googling.
"Lunar-resonant streetlights". They exist!
 Designed by Civil Twilight Design Collective. The lamps use led bulbs and respond to moonlight, dimming according to the level of lunar brightness.
A book reference which may potentially provide info on calculations etc: Light and Color in the Outdoors By Marcel Minnaert