Israel’s eVolution Networks’ Smart Energy Solution (SES) examines cell phone usage rates, locations, energy costs etc. to activate and deactivate base stations as needed. It is saving Telefonica up to 35% of its energy costs. Warren Buffet has now decided to invest in eVolution.

http://www.timesofisrael.com/power-investor-warren-buffett-backs-israeli-power-saver-tech/