| > 2. modern 100 W light bulbs typically use LED and only require ~14 W of power (so ~14% of the power draw) You are limiting yourself to residential light bulbs, which previously typically came in "100W" (actually 1,600 lumen) and "60W" (actually 800 lumen) varieties. Yes, the modern indoor 1600 and 800 lumen bulbs now use less power. But if you look up street lights, you'll find HPS/Halide can use 100-400W, while modern LED use 50-150W. Also architectural lamps that wash against the side of a building may have different outputs. Given the hundreds/thousands of street lights out there, if (say) half the light is going up (or even sideways) that's a lot of waste: we could all the photons that are going up/out could be redirect down then we could reduce the power needed even further. > 3. neither of the above actually matter though because power at night is essentially free; wind turbines, hydro, geo thermal, etc. all continue to work at night and can't be easily shut off, even though demand for power is much much lower. And what does this light do to people's (and animals') circadian rhythms? What does the excess glare of street lights do to road users (like drivers), especially after it has rained? What have we lost 'culturally' by not being able to see the stars? |