Quote from another forum/comment thread:
Power Line Adapters (PLAs) whilst seemingly a good solution to home
networking are essentially a very poor technology. They pollute the
radio spectrum, interfere with your neighbours radio (preventing
reception of Short Wave broadcasts) and do not adhere to the European
They rely upon your internal house wiring to pass signals between
units. Unfortunately, your house wiring is a good ariel and these
signals go far beyond your house, many 100s of yards and in some cases
get into external telephone lines and street wiring and have even been
known to radiate from lamp posts. The units effectively become the
same as an illegal radio transmitter.
The government and OFCOM know the problems regarding PLAs and will
respond when complaints are made by your neighbours, by removing the
devices, so please ensure that the retailer has a sale or return
policy. In a lot of cases involving BT, this translates to BT
replacing the PLAs with CAT5 cabling.
Home networking has a perfectly good wireless system based on the IEEE
802.11 standard (see http://en.wikipedia.org/wiki/IEEE_802.11
is commonly called WiFi and operates at frequencies (2.4GHz) that do
not interfere with other equipment. It is legal, adheres to all
European EMC directives and allows you to transfer your broadband and
gaming system throughout the house.
There are campaigns afoot both at local and governmental level to have
PLAs removed from the shops and banned. Australia has already taken
steps to ban PLA devices.
So in reality, they are not such a good idea after all.