Refoss Smart Home Energy Monitor, Native Open API & Web UI (No Cloud Required), Real Time Electricity Usage Monitor, Power Consumption Meter Works with Home Assistant & MQTT, Solar Net Metering, ETL

I’ve been using the Refoss Smart Energy Monitor for a week now, and I’m thoroughly impressed. One of the standout features is its local integration with Home Assistant, which is precisely why I chose this energy monitor. The instructions were straightforward, and the video on the Amazon listing was particularly helpful, guiding me through the entire installation process. It should be relatively easy for anyone with basic electrical knowledge and some handy skills. However, I recommend doing some pre-planning before installation to determine which circuits you want to monitor. There are five L1 circuit sensor, five L2 circuits sensor, and six circuits sensor that can be used on either L1 or L2. You’ll need to choose one or the other. Additionally, you can combine some circuits and use one clamp for them, as long as they don’t exceed the current limit of the circuit sensor. For instance, I combined two kitchen outlets into one, saving me a sensor I used for monitoring a different. For balanced 240V loads like an AC unit or an EV charger, you can use one clamp and then change the circuit factor to 2 in the Refoss app or create a helper in Home Assistant that multiplies the energy usage by 2. This is because with balanced loads, the energy drawn on both lines is the same, which is why it’s called a balanced load. This way, you can save a sensor to monitor another circuit. I highly recommend making a note of which sensors are connected to which circuits to avoid wasting time trying to remember where you connected them. Setting up the energy monitor on the app was a breeze. I simply downloaded the Refoss app, followed its instructions to connect it to Wi-Fi, and updated the software of the energy monitoring module. The Refoss app allows you to monitor live energy usage for each connected circuit and view a history of energy usage for each circuit, broken down by day, week, month, and year which is awesome for using the app on its own. Connecting to Home Assistant was equally easy. I searched for the Refoss add-on, and the energy monitor was automatically detected on my network. It brought over all the entities shown in the Refoss app and then I got to setting up everything in home assistant. Overall, I highly recommend this affordable and reliable whole-house energy monitoring system. If you use Home Assistant, this is one of the best options out there that is supported natively through the Refoss addon.

I’ve been using the Refoss Smart Home Energy Monitor (EM16) for a few weeks now, and I’m seriously impressed with what it offers. As someone with a solar setup at home, I was particularly drawn to the Zero Feed-In Automation feature—and it works beautifully. Now, instead of sending excess power back to the grid for pennies, the system smartly kicks on high-energy appliances like my water heater and EV charger when solar output peaks. It’s already making a noticeable dent in my utility bills. Installation was straightforward with its clamp-on design, though I'd recommend a bit of caution when handling the current transformers as instructed. Once installed, everything syncs quickly with the Refoss app, which is clean and user-friendly. You get real-time data for each connected circuit—power, voltage, current, and power factor—plus clear breakdowns by minute, hour, day, and even year. The recent update (July 2025) added some killer features: ✔ Merge channels ✔ Export hourly-level data ✔ New energy stats page ✔ Invert CT readings without physically flipping the wires (huge time-saver)Another highlight is the smart alerts. I set thresholds for various appliances, and when something goes over the limit—like my dryer running longer than expected—I get an instant push notification. Great for both safety and savings. Also, it integrates with Home Assistant, which lets me automate energy usage smarter than ever. I love that all data stays local—no cloud dependency, which is a big privacy win. Only downside? It doesn't support Delta 3-phase, but for typical residential setups, this thing is perfect. Bottom line: Whether you're just energy-conscious or running a full solar + smart home setup, the Refoss EM16 is absolutely worth it. I’ve already seen more control over my energy usage and expect long-term savings. Highly recommend!

So far, the Refoss 16-channel power meter has been pretty solid. Install was straightforward, and the hardware feels high quality — about on par with Sense or other higher-end monitors I’ve used. My only small gripe on the hardware side is that it’d be nice if Refoss offered some CT clamp extension cables to help clean up wiring in a 200-amp panel. I have had no issue with the units integrated wireless receiver and it has been very reliable. The app itself is decent, but if you’re coming from Sense, it’s definitely a step down in polish. There’s no device detection or load learning, which feels like a weird omission these days. I’d love to see options to merge CTs in the app or have a bit of smart recognition when certain appliances (like the fridge or microwave) kick on. That said, this thing absolutely kills it with Home Assistant. That’s really where it shines. Setting up automations and triggers off individual clamp readings has been way more reliable than Sense ever was, and honestly, that alone makes it worth the upgrade. Overall, the Refoss delivers great hardware, accurate readings, and solid integration potential. The app could use some love, but if you’re the kind of person who enjoys tinkering and wants full control over your power data, this is a great pick.

I have been trying out the Refoss EM16 Smart Energy Monitor for a while now, and I must say, I'm impressed. It was easy to install—good instructions and helpful online videos meant the whole process was simple and quick. Took about an hour to have everything up and running, and all plugged in to the Refoss app successfully. I like best that this product is so versatile and thoughtful in design. You can just plan and label your circuits ahead of time, and if a clamp is showing up in the negative direction, you can simply reverse it in the app without the need to rewire. If you require additional circuits to be monitored, you can bus their wires together into a CT so long as they're on the same phase. The application is simple to operate, giving real-time monitoring of all the circuits, and detailed energy history by day, week, month, or year. Home Assistant support is where this product really shines. EM16 auto-commands and provides complete local access to all the data of each circuit, enabling advanced automation without the cloud. Solar system owners will love Zero Feed-In Automation—putting extra solar energy to use powering devices such as EV charging points or water heaters rather than returning it to the grid. The recent firmware releases saw the addition of various useful features, including channel merging, export of CSV data, improved dashboards, and inverting CT readings in software. The releases show that Refoss is refining the product according to feedback from users. Overall, the EM16 is a wonderful, budget-friendly energy monitoring system—easy to install, full of data, and ideal for smart home residents as well as anyone wishing to gain better control of and track their home energy usage. Highly recommended.

I self installed this on my 200amp panel and it works very well. Installation was straightforward as long as you’re comfortable doing work inside the panel (make sure the power is off!). It’s been really useful to see where unexpected power draws are coming from, such as a heater in one of my adult children’s rooms that I did not know about! Recommended for all who enjoy having details of what’s happening in their house.

Overall a good product after monitoring for a few hours. The app could be more user friendly and organized a bit better. Like some others have said some sensors are wired backwards and will give you a negative value even if installed correctly but is easily overcome with the circuit factor. About half of mine were wired incorrectly. I wish the pig tails were a bit longer to give more options on where to mount the receiver but overall installation was very easy. So far so good, the product is giving me lots of information about energy consumption like it was designed to do. Would recommend

I'm very happy with the EM 16. It does everything I was hoping it would. Install was easy. It took max 30 minutes once I got started. The app connected without issue. I installed all circuits as called out in the instructions but some circuits were showing negative power (as in energy flowing back to the grid) which was definitely not correct. I think that has more to do with my house but either way there are 2 ways to fix that. Either flip the clamp or set the power factor to -1 in the app which is essentially the same as physically flipping the clamp. The Home Assistant integration is great. There's almost no setup to connect it. The integration is native so when I added it to Home Assistant it connected itself to the EM16 without any additional inputs. Tips: - Install is really simple, power off to the whole house, connect the WiFi antenna, connect the power lead directly to a circuit, attached the clamps. - Do some planning before install. Consider which circuits should be monitored if you have more than 16. I wrote it out on excel first which made revisions before I started the install easy. It also made it easy to rename the circuits in the app after setup was complete - Mark the circuits you've planned on the breakers since the circuit numbers won't be visible when the panel cover is taken off. - There are 3 types of clamps, A, B, and C. A and B clamps need to be on different phases. C clamps need to adopt either the A phase or the B phase but they can't be on both. On North American panels, generally, each row of circuits (assuming the panel is oriented with the long edge vertically) is on a single phase. That means starting at the top of the panel and working down each row alternates phases. The photo with the panel cover is after the install. Apart from an antenna there’s no sign of the EM16.

After using this product for about 2 weeks, I can say that I'm very happy with it. It is easy to clip around your power cables, just make sure to have a multimeter or something to test that you are clipping at the correct one. (my installation had lots of colours mismatch). After installing, the Refoss app will automatically recognize it and install it, you will then be able to properly name your transformers and set a multiplier factor (i.e. negative if you clipped it reverted or a greater number if you ran out of transformers and want to estimate a double or triple phase). You can also give a estimated cost/kwh, set consumption alert per transformer, merge channels (i.e. 1 view for a 220v appliance were you clipped a transformer on both phases). I recommend it.