
My idea for the future involves on-demand street lights. With advances in LED (light-emitting diode) lighting, the street lamps could glow with a minimal amount of light to provide a bit of safety, and when a car or a pedestrian approaches, it turns itself on, for only as long as the car or pedestrian needs it. Then it goes back into its quiescent state.
This makes a lot more sense than burning kilowatts and generating photons for no one to see. Who do we think we are -- the universe? The only trouble is that we don't have the vast amounts of energy that the universe has at its disposal. We do need street lamps to light up our life, but only while life is under them.