For home networking there have traditionally been two options – either lay ethernet cables around your house, or use Wi-Fi. It's Wi-Fi that's been widely adopted, with ethernet the better option for range, reliability and security for those that don't want more wires in the home. See all Wi-Fi and Networking reviews.
Powerline adaptors are an increasingly popular third way. They allow you to use your building's existing electrical wiring as a circuit for carrying a network signal. You plug Powerline boxes into different rooms in the house, that piggyback onto mains plug sockets, in different rooms in the house. Here we test TP-Link's reasonably priced TL-PA551KIT. See also Netgear WN3000RP Universal Wi-Fi Range Extender review.
In the box are two identical adaptors from TP-Link's 500+ range. TP-Link rates them for speeds ‘up to 500Mb/s'. The ethernet ports on each unit are gigabit ethernet, which means any data bottleneck you'll experience will be from the Powerline standard and your electrical wiring. Visit: Group test: What's the best powerline adapter?
Most 500Mbps Powerline adapters use 10/100 Ethernet rather than the Gigabit Ethernet used here, so full marks to TP-Link for not throttling the maximum speed by using the slower type of Ethernet – although you'll need a router that uses Gigabit Ethernet too to get the full benefit.
Also an essential feature now almost ubiquitous but missing from early Powerline units is a passthrough mains socket. This means you can plug the adaptor into a power socket and then plug any mains-powered device into the back of the adaptor, so you don't lose any outlets.
The units feature a power-saving mode that means that when no data is moving across them they move to a power-saving mode that's said to reduce power consumption by up to 85 percent.
In appearance the units are smart and white, if a little large. The white face helps them to blend into the room and three LEDs provide status information on power and network activity. But because of their size and the fact that the Ethernet port is on the underside – unlike the top-mounted Devolo dLAN AV500 Wireless+ Powerline adapters – these units won't fit well with power sockets mounted low on skirting boards.
The Devolo Powerline also features three Ethernet ports, even if they are only 10/100 Ethernet.
What distinguishes these Powerline adaptors is their ease of setup, or more accurately lack of setup. Simply plug the units into power sockets and connect the Ethernet cables and you are done. The devices take care of managing the connection over the power lines and so to the router and computer they believe they are directly connected via Ethernet. These TP-Link units perform this task extremely quickly and two seconds after the link is established.
Powerline testing procedure
House #1: We tested the TP-Link AV500+ in a Victorian house with fairly old wiring and the usual array of electronic devices (TV, Sky+, Hi-Fi, lamps, microwave, computers, etc) plugged into the power lines. The Internet router was situated in the office on the second floor, and we used Powerline to test data speed on the ground floor.
If your house was built more recently you may well achieve faster speeds than we did, but we use this house to get consistent speeds for a proper Powerline comparison.
First we must emphasise – as we do in all Powerline reviews – that despite all the Powerline manufacturers claiming 500Mbps speeds these are theoretical maximums, and you will never see such speeds via Powerline. You'll be lucky to get 100Mbps from a 500Mbps Powerline, but don't fret as this is well fast enough for most needs, such as watching catch-up TV or downloading fairly large files. And rest assured it's much, much faster than standard home Wi-Fi.
We got speeds up to 94Mbps but the house average was 59Mbps using Powerline and ethernet. This was a little above the average speed we got in our comparison of Powerline over ethernet, and will be sufficient for most users – we downloaded HD TV with few pauses.
House #2: For the first test in our second real-world trial we placed a unit next to the router and connected it by Ethernet, the power side was connected to the wall via a 4-metre extension lead. The other unit was placed in a room down the hall connected to another 4-metre extension cable.
In this setup the transfer speed achieved was 63Mbps, which is faster than a 40Mbps Devolo unit we tested (Devolo DLAN 500AV) in the same conditions.
We then plugged the second unit directly into the mains without using an extension. This setup saw a data rate of 75Mbps, the same as the Devolo units speed under the same conditions.
For the final test we plugged in each of the units in adjacent rooms with no extension cords, this resulted in a transfer speed of 85Mbps, the best performance equalling 17 percent of that advertised.
Check out all our Powerline adapter reviews and also our group test of the best Powerline adapters we've tested. You can get more information on Powerline including explanations of Powerline speed myths and lots of tips and trick in our feature What Is Powerline.