Wind, Solar-Powered Street Lights Only Need a Charge Once Every Four Days
What’s wrong with wind power and solar energy and right with coal? 
Well, coal can burn around the clock, as long as you have enough of it. But the wind doesn’t blow all the time and the sun doesn’t shine all the time. Sure, you can store power in batteries, but how much?
How about enough to power an LED streetlight, without wires, that is sure to turn on every night?
There’s a French company called Windela that has crossed a streetlight with a vertical-axis wind turbine and a solar panel. It charges up during the day, when the sun is shining or the wind is blowing. At night, it shines.
It also can work as a Wi-Fi relay, similar to a solar streetlight known as Starsight. Imagine it: Wi-Fi, light at night, no coal required.
