HomePlug adapters are a great way to extend internet from a router to reach any room in the house, without laying new ethernet cables.
They can even extend internet to a garage, outbuilding or garden room, if that building is connected to the house electrical circuit.
What Are HomePlug Adapters?
HomePlug is the family name for several power line communications specifications, developed by the HomePlug Powerline Alliance. HomePlug adapters are also commonly called Powerline adapters.
These adapters plug into a standard electrical socket and allow devices to communicate with each other through existing home electrical wiring. There is no electrical work required – the adapters are truly plug and play.
A typical use would be to connect 1 adapter to your router and connect a second adapter to a PC/Xbox etc at the other side of the house. Network data (e.g. internet traffic) between the adapters passes through the home electrical wiring, providing internet access to rooms that are far way from the router’s location.
Why Are HomePlug Adapters Useful?
Most homes use a wireless router to provide internet access. Routers allow wired connection (via Ethernet cable) to a nearby PC or wireless connection to laptops and phones etc in other rooms.
Wired connections are quickest and most stable but often only make sense for computers in the same room as the router. Other rooms in the house can be too hard to reach with ethernet cable – especially if you don’t want to rip up flooring or drill through walls to lay new cable.
So devices in other rooms of the house (and in outside buildings) have to use a wireless connection. However, WiFi can be slow or unreliable if the device is too far away from the router or if the signal is broken up by thick walls.
If a wireless signal does not reach (or is very weak in) certain rooms then internet access there may be impossible or interrupted as the WiFi signal keeps dropping.
HomePlug adapters provide a simple solution – they extend internet by turning your mains electrical wiring into a wired network, passing internet through to wherever you want.
What Speed Do HomePlug Adapters Support?
The original AV specification was limited to data transmission speeds of 500 megabits per second as it used only the neutral wire in home wiring to transfer data.
The current specification, AV2, was introduced in 2012 and has had several incremental increases in speed since. It improves speeds significantly by using the live wire as well as the neutral wire in the electrical wiring (Devolo adapters use the ground wire too for even faster speeds, in countries that have a ground wire).
Current AV 2 speeds are measured in megabits per second and range from AV2 600, AV2 1000, AV2 1200 up to AV 2000.
Note that these are theoretical, not real world speeds. Actual speeds will depend on the condition and age of your home electrical wiring, the distance between adapters and even the electrical ‘noise’ interference from major electrical appliances in your home.
In real world tests, AV2 600 may achieve 30-60 Megabits per second (depending mainly on the distance between adapters). AV1200 adds higher potential maximum speeds, perhaps 30-110 Megabits per second.
AV 2000 isn’t generally worth paying extra for – real world speeds are much the same as cheaper AV 1200 adapters.
In my opinion, AV 1200 should be fine for internet use, sharing documents or streaming HD video. For comparison: a typical wireless N network will only achieve theoretical speeds of up to 300Mbps so Powerline compares well.
Are Powerline Adapters Backwards Compatible?
AV2 standard adapters should all be backwards compatible with each other. So if you already have a couple of AV 2 600 adapters you can buy a pair of AV 1200 adapters and they should all work fine on the same network – especially if they are all from the same manufacturer.
Adapters from different manufacturers should also be compatible with each other if they share the same standards (e.g. AV2). If in doubt, stick to the same manufacturer for best compatibility.
Types Of Powerline Adapter
There are several different types of adapter:
- Standard adapter with one ethernet socket – to connect to a router or feed 1 wired device e.g. a PC
- Standard adapter with 2 or 3 ethernet sockets – to feed more than 1 wired device e.g. a PC and an Xbox [see tip below]
- WiFi adapter – has at least 1 ethernet socket for a wired device but also creates a new WiFi network – to feed wireless devices like laptops and mobiles
In addition, all 3 types may be available with ‘pass-through’ which means they have a socket on the front that you can plug a standard electrical device into – this avoids using up a power socket, useful if the room only has 1 spare socket available.
Tip: if your adapter has only 1 ethernet socket you can still use that to feed several wired devices by connecting it to a cheap 5 port network switch like the Netgear GS305 5 port Gigabit switch, check price at Amazon. Just connect the adapter to the switch via ethernet cable then connect your wired devices to the switch – all plug and play.
Some adapters also have colored lights to indicate the strength of the powerline network signal – good as a quick guide way to highlight problems. But this isn’t essential – you can test the throughput of the network by timing the transfer of some large files or by running an internet speed test to see if data transfer speeds are reduced in different sockets or rooms.
How Does HomePlug Work?
You need at least 2 HomePlug adapters to extend your existing internet to a new location so, when buying, do make sure you are buying 2 units, not just one. Adapters are often sold in ‘starter kits’ that contain 2 adapters, such as the TP-Link AV 1000 WiFi Powerline kit, check price at Amazon.
One adapter plugs into a power socket near your router and connects to the router via the supplied ethernet cable.
The second adapter plugs into a power socket in the room you want to extend internet access to and connects to your PC (or other wired device) via the supplied ethernet cable.
Internet data is passed through the house electrical circuit transparently – just as if you had connected your PC directly to the router.
For wireless devices like laptops and phones you may not be able to use ethernet cable to connect to the second adapter so you need a WiFi adapter instead.
A WiFi powerline adapter has integrated wireless networking – it creates a new WiFi network that you can connect to from your wireless devices.
If the WiFi signal from your router doesn’t currently reach the whole house, this is a great way to extend WiFi – your router can supply wireless to devices in one side of the house and the powerline WiFi extender can supply wireless to the other side.
Tip: if you don’t have a WiFi adapter, advanced users could set up an old/cheap cable wireless router to provide WiFi from a standard adapter – connect the adapter via ethernet to the cable wireless router, then set up the cable wireless router to provide a new wireless network. You will be using the powerline adapter (instead of a cable modem) to provide internet to the router – see our guide on setting up a cable wireless router.
Can You Use More Than 2 Powerline Adapters?
You need at least 2 adapters to provide a network – you can easily move the second adapter to another room if you want to permanently change its location.
But, if you want to extend network coverage to more rooms (or buildings outside) then you can buy more adapters – up to a maximum of 16 adapters per powerline network.
E.g. if you have 4 adapters (1 connects to the router) you can supply 3 other locations with internet access (or wireless networks if they are WiFi adapters).
Can You Plug A Powerline Adapter Into An Extension Lead?
Manufacturers always recommend that each powerline adapter is plugged directly into a power socket (not an extension lead or a surge protector) to prevent interference from other devices attached to the same extension.
In my own experience, the adapter may still work on extension leads but speed is likely to be reduced, or the connection may become intermittent.
This becomes more of an issue the further away the adapter is from the router’s location, because the signal is already weaker (and speeds slower) at longer distances. A lot will depend on the condition of your electrical wiring too.
As mentioned above, if you don’t have a spare wall socket the safest option is to buy a ‘pass-through’ adapter that has a power socket built in – you can then plug another electrical device into that.
Are There Any Security Issues With Powerline Adapters?
In old AV devices there used to be a possibility that data signals could travel through the power lines to outside of your home so, theoretically, they could be intercepted by someone nearby who used similar adapters. So adapters had to be paired together with a security button on each adapter (like WPS on modern routers) or set up with a shared password via a configuration webpage.
But modern AV 2 specification adapters typically use 128-bit AES encryption to make the powerline network safe and private. This level of encryption is at least as good as the WPA2 encryption used by most wireless routers so the risk is no higher than that of a router’s standard wireless network.
Powerline Adapter Pros and Cons
- No need to rip up flooring or walls to extend a wired ethernet network
- WiFi adapters can extend your wireless coverage to more rooms and areas that are out of reach of your router
- Plug and play so no set up required, just plug them into a power socket
- Simple to move them between sockets or rooms – and take them with you if you move house
- Cheap to buy, compared to the cost of cable installation or installing WiFi repeaters
- They generally only work on the same electrical supply (panel or consumer unit) so if you have different subpanels for an outside building or extension the powerline signal may not bridge across. To be honest, the best way of finding out is to try them and see – there are so many different types of circuits and quality of wiring that it’s hard to be sure what will work without testing
- As the adapters are bulkier than a standard plug, make sure you have enough space around the wall socket to plug it in
- Each adapter uses up a power socket – if this is an issue, choose a pass-through adapter
- Electrical noise or interference can reduce speeds or even block the powerline network completely. In my experience this isn’t common (and any drop in speed may not be noticeable) but you may need to experiment and work out which appliance is causing most interference e.g. a lighting system that has a dimmer switch or a short wave radio