What is powerline networking?

Author: Matt Powell

Last updated: 13 March 2024

There’s no doubt Wi-Fi is a wonder of the modern age, making it effortless to connect devices across your home without the need for wires.

But sometimes signals just aren't strong enough to cater your entire home. When this happens, you need to complement your wireless with wired connections.

If your Wi-Fi doesn’t have the reach, then try powerline networking. It’s an affordable and easy way to use wired networks.

What's a powerline adapter?

Powerline network adapters, aka HomePlugs, are devices that transmit data over your home's electrical wires.

They transform an electrical circuit into a data network. This allows you to create a wired network with minimum effort and without requiring miles of cabling snaking throughout your home or office.

To get started with powerline networking, you only need two powerline adapters and a couple of network cables.

One adapter is plugged in next to the main wireless access point, which will be your home Wi-Fi router, and linked with a network cable. The other adapter can go anywhere on the same electrical circuit, which for most of us will be anywhere in our home.

The other end could provide wired connectivity to a device, such as a computer or games console, in another room or extend a Wi-Fi network using a powerline Wi-Fi booster.

Powerline adapters usually connect automatically and don’t require software or any configuration. Once you’ve got that second adapter powered up, you can bring internet connectivity and home networking to any devices on the other end right away.

What kind of HomePlug adapter should I buy?

There’s a massive variety of powerline gear with many added extras to suit most requirements, so what should you look out for when buying?

Speed

The key difference to consider when choosing the best powerline adapter is data transfer speed.

Early HomePlug models were only capable of a tiny 14Mb transfer rate, but today's entry-level models offer 200Mb or 500Mb, and the latest hardware boasts speeds of 1200Mb+. These speeds sound like they should be matching what you’d be getting from your router on its own.

However, you should take advertised speeds with a pinch of salt.

A 1200Mb adapter will, in reality, provide a performance of 100-120Mb at best, while the 500Mb models deliver about 60Mb, and 200Mb adapters are typically capable of around 30-40Mb.

Make sure you remember that Mb or Mbps is a measure of speed in Megabits Per Second. It’s not to be confused with megabytes or MB, which is the size of a file. At a transfer rate of 100Mb, it would take eight seconds to move 100MB of information.

You should consider how this will impact your usage. If you’re using powerline adapters mainly for web browsing, then a 200Mb adapter will easily suffice. But if you’re planning on streaming HD video or frequently transferring large files, then it’s worth investing in faster adapters.

Take your broadband speed into account, too, or you could find performance takes a hit when using the powerline connection.

Anyone with fibre broadband should get a 500Mb powerline device at a minimum. If you’ve got a speedy connection, like Virgin Media’s M500 Fibre Broadband, you should use the fastest powerline adapters available to avoid limiting the broadband performance.

Finally, it's important to check the network interface on your devices. For a long time, the standard speed of a wired network connection was 100Mb, and lots of computers and other hardware will be limited to that rate. But newer equipment may support faster gigabit ethernet cables.

If you’re planning on using powerline networking for speeds above 100Mb, you’ll need to make sure you've got a gigabit connection on your device.

Ports and pass-throughs

A basic HomePlug will have a single ethernet port, but some models offer several ethernet connections, so you can connect multiple devices.

The multiport adapters are usually only a little more expensive and worth it even if you don’t need those ports right away. Otherwise, to add more ports, you’ll either need to replace the adapter or use a network switch. If you have left it a little late, a network switch isn’t expensive, but it will be extra clutter.

Some adapters will also have pass-throughs for the power socket. This isn’t an essential feature, but it’s a useful thing to have if power points are at a premium.

Wireless extenders

Some powerline adapters also have built-in Wi-Fi extenders. This is a great way to bring Wi-Fi connectivity to areas of your home where the signal is weak or non-existent.

Compared to Wi-Fi repeaters which amplify a weak signal, the connection should be faster and more stable. Unfortunately, you will still lose some performance compared to directly connecting to the router. Moreover, you need to be prepared to pay a bit more for this capability.

Frequently asked questions about powerline adapters

• Can I use a powerline adapter on an extension socket?

  Powerline adapters may work with an extension lead or power strip, but this can impact speed and reliability. Surge-protected extensions, in particular, can result in a very noticeable hit to performance and might not work at all. 

  If you’re not transferring lots of big files, streaming HD movies, or trying to get the maximum broadband speed at the other end, then it might not matter. Otherwise, they should go straight into the wall for the best performance.

• Why is my powerline connection so slow?

  Distance from your router, other electrical items and the quality of your power lines can all affect performance.

  If the speed is poor, you should try other sockets and run a speed test at each point to find the best position.

  Some adapters have indicator lights that give a rough idea of the speed.

  Also, keep in mind what we said above about the speed of powerline adapters. The advertised speeds aren’t realistic. In practice, the data transfer speed will be far lower than the claims printed on the box.

• Are powerline adapters backwards compatible, and can I mix adapters from different manufacturers?

  If you're buying a new powerline setup, you are best off getting the same make and model to ensure compatibility.

  However, leaving aside the reduced performance when connecting to a slower adapter, mixing powerline kits of different speeds from different manufacturers isn't usually an issue so long as they support the same standards.

  The most popular type of home powerline starter kit is HomePlug. Just as Wi-Fi has been standardised, the HomePlug Alliance has created specifications for manufacturers to follow to ensure a dependable level of performance and compatibility.

  HomePlug 1.0 was the original specification but has since been supplanted by HomePlug AV and HomePlug AV2 adapter kits.

  Any adapter meeting a HomePlug AV standard should be compatible with another. But older HomePlug 1.0 devices won’t usually work with AV, though they should be able to coexist.

  There are other types of powerline standards, notably the competing HomeGrid, aka G.Hn. These devices won’t work with HomePlug adapters, but since they’re not widely available in the UK, you’re unlikely to encounter this problem.

• Are Powerline adapters secure?

  If your wireless network is already secure, you shouldn’t have much to worry about. In order for someone to gain access to devices on your network, they would need to either connect to your Wi-Fi or plug in to the network.

  If your powerline adapters have any kind of management options you’ll be provided with a username and password in the box to access these settings. Assuming this is not a generic login for every adapter from the same manufacturer it should be relatively safe. But if it’s shared, you’ll definitely want to change it to something unique.

  For further help with home network security, visit our guide on changing your router settings.

• Are Powerline adapters better than using Wi-Fi?

  Depending on what you’re using the internet for, both powerline adaptors and Wi-Fi can provide similar speeds. Powerline adaptors can give you a stronger connection at a further distance than your standard Wi-Fi range can, but both can be limiting.

  If you’re going to be doing a lot of large downloads or gaming, we’d always recommend using a wired connection directly into the router for the best speeds. But if you’re happy with your Wi-Fi speeds, you won’t need to invest in a powerline adaptor.

Expert Summary

Powerline networking is a great way to get broadband around your home. With a single wired plug attached to your router, you can use further plugs to get internet all over your home. If your Wi-Fi isn’t as fast as you’d like, and a wired connection won’t work for you, a powerline network could solve your problems. Some powerline adaptors can also work as Wi-Fi extenders, which is another bonus if you have any internet weak spots.

Powerline networking works with every form of broadband provided you have a Wi-Fi router. So use our deals checker to see what packages are available for you.