> if you power it with "green energy" then it doesn't really matter pollution-wise, and cost-wise it takes a long time to recoup the cost of switching all the b

> if you power it with "green energy" then it doesn't really matter pollution-wise, and cost-wise it takes a long time to recoup the cost of switching all the bulbs in energy savings. It doesn't matter what energy source any individual application is using, it only matters what happens at the margin. For example, if a city switching to slightly more efficient lightbulbs allows a coal power plant to be mothballed one year earlier, then it saves an entire year of coal power emissions from happening. Furthermore, streetlights operate on a complete inverse power curve to solar, meaning that additional solar is very unlikely to benefit streetlight power.