Powerline does work with limitations. Its been around here for quite some years now. It works if you stay in the ring main. Speed is not that great and if the signal goes through the circuit breaker box it screws it.
Sorry I have to disagree. I have used them where the router was at the end of a large old house and where the signal was required was in a stand alone annexe fed via a sub-main.
The whole thing works faultlessly and is not discernibly slow enough to be of concern.
mixture links to a report that indicates that interference CAN occur. Judging by the hundreds in operation I am not sure how much of an issue it is.
I use
Solwise Homeplugs
At under £40 to solve your problem completely in a matter of minutes it strikes me as being something of a no-brainer.
Just my opinion of course.