[youtube]https://www.youtube.com/watch?v=52YKJ31pde0;
Think of all the electricity that's wasted by city lights that stay on when no one needs them. To solve this problem, one Barcelona neighborhood is using a system of Endesa LED lights, controlled wirelessly, to provide light exactly when, and where, it's needed. It keeps the streets safe while saving the city money.
Psychologist says people who never comment on social media share these 5 positive traits