Power over Ethernet sounds like deep electrical territory, but it is one of the most genuinely money-saving ideas in office networking - and most owners have never had it explained. In one line: it sends both data and electrical power down the same network cable, so a device like a ceiling Wi-Fi point or a camera needs no nearby plug socket. That small fact removes a surprising amount of cost and hassle.
One cable, two jobs
Normally, a networked device needs two things: a network cable for data, and a power lead plugged into a wall socket. Power over Ethernet, almost always shortened to PoE, lets a single standard network cable carry both.
The power comes from a PoE-capable network switch (or a small in-line injector) in your comms cupboard. The cable runs to the device - and that is all the device needs. No electrician at the ceiling, no extension lead trailing to a camera, no socket behind the desk phone.
Where the money actually disappears
The savings are not in the technology itself, which is cheap. They are in everything you no longer have to install or pay an electrician to do.
- •No new mains sockets at awkward, high or outdoor locations - often the single biggest line on a fit-out quote.
- •Devices go exactly where they work best (a ceiling, a corridor, a car park) rather than wherever a socket happens to be.
- •One cable per device to run and label, not two - faster installs, tidier comms rooms.
- •Central backup power: put one battery backup (UPS) on the switch and every PoE device rides through a power cut.
- •Easy moves: relocating a camera or access point is a cable change, not an electrical job.
What you can run on it
If you have noticed how few cables modern offices seem to have, PoE is usually the reason. The everyday devices it powers are exactly the ones that are awkward to plug in.
Common PoE-powered kit includes wireless access points on ceilings, IP security cameras inside and out, VoIP desk phones, door-entry and access-control readers, digital signage and display screens, and small sensors. Newer, higher-power versions of PoE can even run some laptops' docking points, monitors and compact devices - the ceiling of what it can drive keeps rising.
The one number to check
PoE comes in power levels, and matching them is the only technical care you need to take. Lower tiers suit phones and basic cameras; higher tiers (often branded PoE+ and PoE++) are needed for pan-tilt-zoom cameras, the latest Wi-Fi access points, and anything hungrier.
The practical rule: make sure the switch can supply enough power for what you plug in, and check the switch's total power budget across all its ports - a switch might power eight small devices comfortably but not eight power-hungry ones at once. This matters more as kit gets thirstier: the newest Wi-Fi 7 access points draw more than older ones, so a PoE switch bought years ago may not have the headroom for them.
Specifying it without overthinking
For most offices the decision is refreshingly simple: when you buy or replace network switches, buy PoE ones. The premium over a non-PoE switch is modest and it future-proofs you for cameras, phones and access points you have not even planned yet.
Pair that with a thought about resilience - a single battery backup on the switch keeps your cameras and Wi-Fi alive during an outage - and a thought about segmentation, because PoE cameras and IoT devices are exactly the kit you want isolated on their own VLAN. Get those three things right and PoE becomes invisible infrastructure that quietly saves you money for years.