Best Energy

The Zooz ZEN04 is a compact single-outlet Z-Wave smart plug with built-in power monitoring. It pairs with any certified Z-Wave hub, including Home Assistant with a Z-Wave radio, Hubitat, HomeSeer, and SmartThings, and it reports on/off state, watts, kilowatt-hours, voltage, and amperage without a vendor account or cloud service anywhere in the loop.

The Shelly 1PM Gen3 is a compact Wi-Fi relay with built-in power metering, the third-generation successor to one of the most popular DIY smart relays ever made. It installs behind a wall switch or outlet, switches loads up to 16 amps on 110-240 volt AC circuits, and continuously reports active power and accumulated energy use — a smart switch and an energy monitor combined in a single flush-mount module roughly 41 by 36 by 17 millimeters.

The Emporia Smart Plug is a Wi-Fi smart plug built around energy monitoring rather than treating it as a checkbox feature. It is UL-listed, rated for 15 amps, and feeds per-outlet consumption data into the same Emporia app that serves the company's Vue whole-home energy monitors, which makes it the usual pick for people assembling a low-cost picture of where their electricity goes, appliance by appliance.