The Commission for Dark Skies


The economic cost of wasted light: money and energy ‘glowing to waste’

The most visible, yet largely ignored aspect of energy waste is that of night-time lighting. If water were leaking from the mains every few metres, action would very soon be taken. We walk past wasted light from streetlamps, sports facilities and domestic floodlights and give it little thought. How much energy is wasted by light pollution? How much money? Can this even be calculated? It is impossible to know exact present or future lighting costs: the technology, and prices and global demand change too rapidly. The only certainty: waste light costs a lot of money. Two modern estimates: European dark-sky organisations suggest a figure for the continent of Europe, based on satellite monitoring, numbers of lights and estimated efficiency, of two billion Euros annually. The International Dark-Sky Association concludes that about a third of exterior lighting in the U.S.A is wasted through misdirection, costing about 2 billion dollars a year. Before we invest all our faith in alternative sources, we need to cut down on the energy that we use, and waste, through inefficient lighting, heating etc.

LED lamp on a hospital wall

LED lamp on a hospital wall (Image: Bob Mizon)

Why do we still see new lights being installed which are too bright, shine where their emissions are not needed, and are often simply unnecessary?