I actually don't believe that Force lightning has enough kinetic force on its own to do what Sidious and Dooku have done with it.
In AOTC, when Dooku electrocutes Anakin, the lightning courses through him for a moment, before he is thrown sideways into a wall. A throw through the Force much like when Dooku threw Obi-Wan like a rag doll.
In ROTS, I believe that Sidious did indeed use an additional Force power in the form of a push to rocket Mace's near-dead form out the window.
The reason perhaps, that Yoda was sent flying into a wall was because of his small size. Likely enough to be lifted clean off of the ground. Although there may be more to it.