BT is selling a pair of 500Mbps Powerline AV adaptors, the Trendnet TPL-4012E2K, for only £27.51 excluding delivery - that’s less than £14 per unit.
Each comes with a Gigabit Ethernet port and up to 16 can be used without running new cabling. The adaptors can be controlled using a Windows utility, and a trio of LED lights allows easy troubleshooting.
Unfortunately, the adaptors are not pass-through, which means that you lose one wall power socket when you use one of these, nor are they PoE (power over ethernet) capable. Also, they consume around 5 Watts when in use.
Other features of the device include 128-bit AES encryption, a three year warranty and HomePlug AV compatibility. Note that it is compatible with Windows but not with Mac or Linux.
Usually Powerline adaptors are used to complement rather than replace wireless networks. They are great to create access points in rooms where network signals are weak, when paired with a wireless router.
The maturity of the Powerline market means that these adaptors can now be used for anything including smart TVs, network attached storage and even games consoles.