Choosing an energy monitor for your home is really a question of scope: do you want a whole-home system that tracks your solar production and overall usage, or a single-circuit smart meter that lets you switch a device on and off while measuring its draw? The Sense SM2 and the SONOFF POWCT take two very different approaches, and the right one depends on the depth and size of the project you have in mind.
Quick Verdict
For a complete view of your home's energy, the Sense SM2 (USD 199.99) is the system-level pick, with four CT clamps and dedicated solar sensor clamps. For a focused, less expensive monitor and switch, the SONOFF POWCT (USD 34.99) offers a split CT sensor, new condition, and support for both Alexa and Google Home. The Sense is open-box but unused; the SONOFF is new.
Comparison Table
| Feature | Sense SM2 | SONOFF POWCT |
|---|---|---|
| Price | USD 199.99 | USD 34.99 |
| Best for | Whole-home monitoring with solar | Single circuit or appliance |
| Connection | Wi-Fi, Alexa | Wi-Fi, Alexa and Google Home |
| Sensing | 4 CT clamps (2 main + 2 solar) | Split CT sensor, up to 100 A |
| Condition | Open box, unused components | New |
Where Each Product Wins
The Sense SM2 wins when you need the full energy picture. Its four current transformer clamps let you monitor the main lines and solar production simultaneously, and the system connects to your home network over Wi-Fi for continuous tracking. The Sonoff POWCT wins on everything that matters for a single circuit: it's new, compact, and works with both Alexa and Google Home. The split CT design means you can clamp it around a wire without making direct contact with live conductors, and the built-in switch adds remote control.
Product Notes
UNUSED Sense SM2 Home Energy Monitor System w/ Sense Solar Sensors
If you want a complete picture of your home's energy, including solar input, the Sense SM2 is the system to consider. The package includes the monitor, two CT150 main current sensor clamps, and two additional solar sensor clamps-four total-so you can track both consumption and production. It connects over Wi-Fi and works with Alexa. That said, this is an open-box unit: the boxes have been opened and the packaging shows shelf wear, scuffs, and edge wear from storage. The system has never been installed or used, so the components are unused, but you'll need to be comfortable with cosmetic wear on the original boxes.
SONOFF POWCT Smart Power Meter Switch Energy Monitor Work with Alexa/Google Home
The SONOFF POWCT is a smart power meter that gives you a focused view of one circuit or appliance, and it doubles as a switch you can control from the eWelink app. Its split CT sensor clamps around a wire without touching live conductors, which lowers the installation risk, and it's rated for up to 100 A of current detection. The unit is new, with a white PC casing and an SMA antenna, and it works with Alexa and Google Home. The limitation is scope: it monitors the one line you attach it to, not your entire home, and it's intended for indoor installation. If your goal is to track a single high-draw appliance or a room's circuit, this is the practical pick.
Final Choice by Use Case
If you're setting up a full home energy monitor and you have or plan to have solar panels, the Sense SM2 is the better match. It comes with the main CT clamps and solar sensor clamps, and the open-box status doesn't affect the unused components. If you want a new, less expensive way to watch and control a specific appliance or room circuit, the SONOFF POWCT is the more practical choice. It gives you energy data, switching, and voice control without the whole-home system's cost.
