When most people look at an Ethernet cable, their first thought would be that this is how you transport data. However, you’ve probably seen devices like security cameras or network switches that aren’t only sending data over Ethernet, but also receiving power using that one cable.
Ethernet isn’t just for data
More powah!
Power over Ethernet (PoE) is exactly what it sounds like. It’s a standard that allows power to be sent over an Ethernet cable. This means that devices that fall within the PoE power range don’t need to be near an outlet, and you don’t need a separate power adapter.
Security cameras are an obvious use case for this technology. After all, you usually place them in spots that don’t have good power access, and you’re going to run Ethernet to them anyway, so if you can also power those cameras at the same time, it’s going to be the most secure and elegant solution. It also makes it easy to centralize your backup power, which is a big deal when it comes to security. An even more obvious use for this technology is to power a network switch. So it’s easy to offer ample Ethernet ports anywhere, without worrying about a building’s electrical wiring.
Security cameras are only the beginning
Free yourself from the grid
Security cameras might be a good place to start, but once you have a standard that supplies a guaranteed level of power, hardware designers can let their imaginations run. Wireless access points are a great candidate for PoE, and it allows you to position them in optimal spots for wireless performance. That’s usually not conveniently close to an outlet.
You can also make use of PoE VoIP (Voice over IP) phones, which is perfect, because those phones also use data over Ethernet to communicate. Ironically, this brings VoIP up to analog phone convenience, because, of course, phones also get their power from the phone line.
- Brand
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StarTech.com
- Length
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125ft
This extra long StarTech Cat-6 cable is a high-quality Ethernet cable that supports up to 10Gbps data transfer speeds.
Modern PoE can run surprisingly power-hungry devices
Going beyond a switch
The PoE standard allows for 15W of power, and with power loss over the cable there’s about 13W left for devices. That’s not bad, and devices like smart doorbells, intercoms, and SBCs like the Raspberry Pi can be powered this way.
That was the starting point, but with subsequent PoE revisions, the power level has gone up to 30W, 60W, and as much as 100W. Of course, there’s still power loss over the cable, so you might only get 70W out on the other side, but this really expands the types or number of devices you can run.
Just keep in mind that your PoE power source, such as a big powered switch, still has to split its power across multiple Ethernet lines. If the switch can put out 150W in total, then it doesn’t matter that each individual port is rated at 100W. The total budget is still just 150W.
There are also POE to USB-C converters, which really makes this a versatile power delivery system. There are many more devices that accept USB power than Power over Ethernet, and now you don’t have to choose.
Why power over Ethernet is safer than extension cords
Especially that really old one covered in dust
Because power is centrally managed through a PoE switch, every connected device benefits from built-in protection against overloads, short circuits, and power faults. If something goes wrong, the switch can shut off power to that individual port without affecting the rest of the network.PoE switches usually allow admins to cycle power, so you can remotely restart devices without having to unplug anything.
However, you should be careful when using “passive” PoE (as explained by Netgear) since passive systems don’t negotiate power levels, and it’s possible to damage a PoE device if a passive system gives it too much power. Passive PoE is not an official part of the standard, hence the warning. However, the active systems that you’re most likely to find today solve this issue. Some specialized equipment might still use passive PoE, but you should almost certainly avoid it.
Is your network ready for PoE?
It’s pretty easy to get started with PoE. Most people just start with a PoE switch, which is where the power comes from. However, if you already have a non-PoE switch, and you only need to power one or two gadgets, you can use a PoE injector to add power to specific lines without replacing your entire switch.
The good news is that most existing Ethernet cabling already supports PoE. Cat5e, Cat6, Cat6a, and newer cable standards all work perfectly well, although higher-quality cabling handles higher power levels and heat more effectively, especially over longer cable runs.
PoE is a great technology to invest in, especially as smart home tech and small devices that can run from PoE or USB converted from PoE become ever more numerous.


