We call this Zhenjin, or shocking power. It's not that hard to learn but requires a fair bit of training. It probably took me six months of daily training to be able to use it in sparring and three years to get really good at it, by which point it was scary effective and people stopped sparring with me..
Mind you, I was training a lot of other things too, so it could be done quicker. The power comes from rapidly dropping your centre of gravity whilst issuing some power into the ground, then, when, the ground sends back an equal force, re-directing that force into your opponent in the form of a wave.
The great thing about it is that it doesn't rely on acceleration, will do a similar amount of damage no matter where your fist is in the punching process, can be done whilst moving backwards and forwards, has great stopping power and can be used with or without a weapon.
Note: You will still need to be able to make contact with them for it to be of any use.