Hmm, the article mentioned nothing about the weight. For a medium sized quadcopter, 3 times more energy (given the same weight) means as long as 3 hours of flight time which would make all these drone delivery dream come true.
Unfortunately, as hwillis explains in another comment (https://news.ycombinator.com/item?id=13779143), it's not 3x energy for the same weight, it's 3x energy for the same size. It seems to actually be about 2.5x heavier for the same energy.