PoE vs WiFi Security Cameras

What does PoE actually deliver to the camera?

IEEE 802.3 defines three tiers. The original 802.3af reserves 15.4 W at the switch and guarantees the camera can draw up to 12.95 W, which covers the large majority of fixed bullet and dome cameras sold today. 802.3at, sometimes called PoE+, raises that to 30 W reserved and 25.5 W delivered, which is what a heated housing, a wiper or a small pan and tilt head needs. 802.3bt goes up to 90 W reserved and 71.3 W delivered, the ceiling of the standard, built for a full size PTZ camera running a heater through a winter.

The point of quoting these numbers is that a PoE camera is never power starved by the cable. The single Ethernet run carries more power than almost any fixed camera will ever ask for, and it carries the video signal back over the same wire with no compression loss from a radio link.

Why does a WiFi camera almost always mean a battery?

Some WiFi cameras plug into an outlet, but the popular outdoor WiFi cameras are battery powered because that is the only way to mount them where there is no outlet, which is most of the places a security camera actually needs to go. A battery has to run the sensor, the WiFi radio, and usually a bright infrared or white light array, and WiFi radios are notably power hungry compared to the low current draw of a wired Ethernet chip.

The result is a maintenance task that never ends: recharging or swapping batteries every few weeks to few months depending on how much motion the camera records, and doing it more often in cold weather because lithium batteries lose capacity as the temperature drops.

Does WiFi ever beat PoE outright?

Yes, and it is worth being honest about when. A solar powered WiFi camera that stores footage on the camera itself, rather than requiring a cloud plan, removes both weaknesses at once: no cable to run and no recurring bill. That configuration earns a real recommendation on this site for a position with no realistic cable route and decent sun exposure, such as a detached shed or a far corner of a fence line.

A rented property is the other clean case. You cannot run structured cabling through a landlord's walls, so a battery camera that mounts with two screws and comes down when you move is the only practical option regardless of what the standard says about power budgets.

What does PoE cost that WiFi does not?

Cable, and the labor of running it. A single Ethernet run to a soffit camera is a manageable DIY task with a fish tape and a drill, but six or eight runs to every corner of a house is a real afternoon of work, and it usually means either an NVR with built in PoE ports or a separate PoE switch to power everything from one place.

What does WiFi cost that PoE does not?

A subscription, in most cases. Cloud based WiFi cameras from the largest brands generally hold only a live view for free and charge a monthly fee for any recording history at all, which over five years is routinely more than the camera itself cost. Battery replacement or recharging labor is a real, recurring cost too, just one that shows up as your time rather than a bill.

• A cloud subscription, if the camera does not store locally
• Replacement batteries or the time to recharge on a cycle
• A weaker signal at range, which can mean a WiFi extender near the camera

The verdict, by situation

Choose PoE for anything permanent: a house you own, a business, any position with a realistic path to run a cable. Choose a solar WiFi camera with local storage for a position with no cable route and good sun. Choose a battery WiFi camera only when neither of those applies, such as a rental, and go in accepting the recharging cycle and, likely, a subscription as the price of the flexibility.