Ok, I think I solved the things now.
LEd vary a lot in efficiency. Some are just 20% efficient and other reach 60% efficience. About domestic LEDs, for room lighting or TV backlight, I don't know, but I bet mosts are more than 20% efficient.
Anyway if this discovery really have how creat a LED with a efficience of 75%, with lower cost and more pure light, it's interesting, but far from make your iphone battery lasts 4x more.
To make the absurd statment some news report said (about last 4x more) they need to ignore the energy consumption of processors and circuits. And they also needs to take as reference the worst kind of LEDs, with efficience of just 20%.
Journalists should be forbidden of make science NEWs, since they all tend to interpret things wrong and distort what scientists said. There should be a special class to wrote about science NEWS.
